ii78~2
Cross-Reference To Related Applications
The invention which is the subject matter of the present
application is advantageously employed with the inventions dis-
closed and claimed in Canadian patent application Serial No.
319,744 entitled COMPUTER CONTROLLED KEY TELEPHONE STATION SET
filed on January 16, 1979, in the name of Frank A. Coviello
and in Canadian patent application Serial No. 304,660 entitled
COMMUNICATION CIRCUIT filed on June 2, 1978, in the names of
Alan Bloch, Frank A. Coviello, Ira Guzik and Candido Puebla.
Ba~kground of the Invention
In various known key telephone systems, the implementa-
tion of the many available services or features required addi-
tional circuits in each station set and additional cond ctors
running from each station set to the key service unit(KSU).
It is not uncommon to have as many as 50 pairs of conductors
connecting each station set to the KSU. Consequently, the time,
'~
i~71~
effort and cost of installing, modifying or moving such key
telephone sets has become excessive.
Some attempts have been made to overcome these problems
by implementing key telephone service features by means of
signal multiplexing techniques, thus achieving substantial
reductions in the number of conductor pairs required for conn-
ection of each key telephone set to the KSU. Although this
approach hæs alleviated the cost and space problems somewhat,
it has been only moderately successful. As before, the addi-
tion of telephone services or features required circuit modi-
fications in the KSU and in the station sets. Also, such
signal multiplexing systems frequently employ a common control
circuit to supervise signalling and control for all of the
station sets. Thus, failure of the common control circuit
causes the entire system to fail.
Summary of the Invention
The present invention is embodied iD and carried out by
an electronic key telephone system in which telephone services
or features are implemented by switching in the key service
unit in response to signals received from the station sets, and
signals received by the station sets from the key service unit
control energization of visual indicators and connection of
internal circuitry in the station sets. The key service unit
includes a distributed space-division matrix with active and
passive ports, and has distributed time-division multiplexed
control with interleaved duplex signalling between the key
service unit and the station sets. All system options are
effected in the key service unit. Each station set is connected
to the key service unit by only four conductors, which form two
voice communication channels. The duplex signalling and the
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power transmission to each station set are both accomplished
over ~ phantom pair lncorporating the four conductors which
form the voice communication channels.
Brief DescriPtion of the Drawing
The present invention may be better understood by
reading the written description thereof with reference to the
accompanying drawing, of which:
Figure 1 is a block diagram of a first preferred embod-
iment of applicants' electronic key telephone system;
Figure 2 is a block diagram of a second preferred
embodiment of applicants' electronic key telephone system;
Figure 3 is a block diagram of the station card circuit
which is a component of applicants' electronic key telephone
system;
Figure 4 is a schematic wiring diagram of a section of
the station card circuit shown in Figure 3;
Figure 5 is a block diagram of the line card circuit
which is a component of applicants' electronic key telephone
system;
Figure 6 is a block diagram of the tone generator card
circuit which is a component of applicants' electronic key
telephone systems;
Figure 7 is a block diagram of the link card circuit
which is a component of applicants' electronic key telephone
system as shown in Figure 2;
Figure 8 is a block diagram of the register card circuit
which is a component of applicants' electronic key telephone
system as shown in Figure 2;
Figure 9 is a partially schematic, partially block
diagram of the page card circuit which is an optional component
of applicants' electronic key telephone systems; and
117t~
Figure 10 is a schematic diagram of the internal con-
ference card circuit which is an optional component of appli-
cants' electronic key telephone system as shown in Figure 1.
FIG. 11 illustrates the connection of a key telephone
station set of this invention to a key service unit by means of
four conductors thereby providing two communication paths and
providing data signalling to and from the key service unit and
the key telephone station set. FIG. 11 also functionally
illustrates the means by which the communication paths and the
logic circuitry are controlled in the key telephone station
set.
FIGs. 12A and 12B illustrate the data format by which
information is transmitted from the key service unit station
set logic circuit associated with each key telephone station set.
Periodic messages are transmitted in which time is divided into
a series of words, each one of the words being associated with a
control function or a particular key on the key telephone set.
During certain time elements of the word, signals are applied
from the key service unit to the station set; during certain
other time elements of the word pulse signals are transmitted
from the key telephone set to the key service unit.
FïG. 13 shows the diagram of the stored program digital
computer (microcomputer) residing in the key telephone set,
being a hardware illustration of the computer.
FIG, 14 shows a switch matrix for generating and trans-
mitting information to the computer regarding the status of
each of 32 switches arranged in eight columns and four rows.
FIG. 15 shows an indicating circuit arrangement whereby
seven columns and four rows of indicators are controlled by
driver circults responsive to outputs of the computer in the
key telephone set.
FIG. 16 shows a key arrangement of eight columns and
four rows in which the first column is designated "zero." The
arrangement, in the form of a matrix, indicates the correspon-
dence between the words of the multiplexed data transmitted
between each telephone set in the key service unit and the
physical switch matrix residing in the telephone set.
FIG. 17 illustrates the computer controlled electrical
circuits used to connect the telephone handset and speakerphone
of the two audio frequency communication paths.
Description of the Preferred Embodiments
Applicants' electronic key telephone system (EKTS)
incorporates the novel concept of a distributed space-division
matrix formed by active and passive ports. An active port is
defined as one which has the ability to seize a passive port,
but cannot be seized by any port. A passive port is defined as
one which has the ability to be seized by an active port, but
cannot itself seize any port. In applicants' system, any active
port can seize any passive port to which it is connected. Any
active port may be connected to any passive port by means of
backplane wirinq in the cabinet of the key service unit. The
sequence of events involved in the seiz~ng of a passive port by
an active port are as follows: (1) interrogating the passive
port by the active port to determine its status (seized or not
seized); if the interrogated passive port is not seized, (2)
closing a talk signal path from the active port to the passive
port; (3) signalling from the active port to the passive port
that it has been seized; and (4) signalling from the passive
port to all other active ports to which it is connected that
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it has been seized. ~f, upon interrogation of the passive
port bv the active port, it is found that the passive port
has been seized, the interrogating active port will not be
able to seize the passive port except in the special case of
an active port which is capable of pre-emptively seizing the
passive port, i.e., in spite of the ~assive port having
already been seized bv another active port.
Referring specifically to the first preferredembx~ment
of applicants' EKTS shown in Figure 1, the system includes a
variable number of electronic key telephone sets 100-1, ....
100-N the details of which are set forth in cross-referenced
application Serial No. 319,744. The key service unit KSU-l
is formed by a variable number of station cards 200-1, .....
200-N equal to the number of station sets; a variable number
of line cards 300-1, ..., 300-K; an optional page card 400, a
tone generator card 500, and an optional conference card 600.
Power is provided to KSU-l by a power supplv (not shown) gener-
ating outputs of ~25 volts DC, -25 volts DC, and -5 volts DC,
and ~ower is provided to each station set 100-1, ... , 100-N
through its associated station card 200-1, ...., 200-N via tle
auad-wire connection, which is described in detail in cross-
referenced application Serial No. 304,660. Each station caxd
200 has an arra~ of active ports A and a numker of passive ports
P. In this embodiment, each station card active port A is oon-
nected either to a passive port P in another station card 200,
or to the passive port P in a line card 300, or to a passive
port P in the page card 400, or to the passive port P in the in-
ternal conference card 600. Each page card ~ne outnut is o~n-
nected to the page inputs of one of four groups of station ~rds
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200. Tone generator card 500 provides the station cards 200
with audible and visual indicator signals for traDsmission to
the station sets 100. In this embodiment, all internal calling
is accomplished ~ithout dialing by actuation of a single station
set pushbutton or key to establish a direct connection through
the associated station card and the backplane wiring to another
station card and its associated station set. This embodiment
employs a non-blocking matrix arrangement that assures connection
to the desired internal station set regardless of the amount
of traffic on the system (if that station set is not busy).
Referring specifically to the second preferred embodiment
of applicants' EKTS shown in Figure 2, the system includes a
variable number of electronic key telephone sets 100-1, ....
100-N as in the system of Figure 1. The key service unit KSU-2
is formed by a variable number of station cards 200, a variable
number of line cards 300, a variable number of register cards
600, a variable number of link cards 700, a tone generator card
500, and (optionally) a page card 400. System power is provided
as in the embodiment of Figure 1, Each station card 200 has an
array of active ports A and a number of passive ports P. In
this embodiment, each station card active port A is connected
either to the passive port P in a line card 300, or to the
passive port P in a link card 700, or to a passive port P of one
other station card 200, or to a passive port P in the page card
400. Each link card active port A is connected either to the
passive port P of a line card 300, or to a passive port P in a
station card 200, or to a passive port P in the page card 400.
Each page cardzone output is connected to the page inputs
of one of four groups of statioD cards 200. Tone generator
3~ card 500 provides audible and visual indicator signals to the
station cards 200, the line cards 300, and the link cards 700
11787~Z
for transmission to the station sets 100 and to the C.O. line,
as may be appropriate. In this embodiment, most internal
calling is accomplished by dialing from a station set 100
through the associated station card 200 and a link card 700
to another station card 200 and its associated station set.
However, each station card does have a hotline connection from
one active port A through the backplane wiring to a passi~e
port P in one other station card. It is also possible to seize
a CØ line which does not bave its line card's passive port P
connected to an active port A of a particular station card by
having that station card seize a link card and then seize that
CØ line via the link card.
In both embodiments, there is an absolute minimum of
common equipment, and so the systems are never burdened with
more circuitry or hardware than is actually needed for any
given installation. Each system also has the capability of
allowing two groups of users to be separated by lines and
stations so that one group has CØ lines that do not appear at
stations in the other group. This configuration has application
when two or more departments or business entities in the same
location wish to be serviced by the same key telephone system.
System installation requires a minimum of time and expense.
Because all system options are accomplished in the KSU, rather
than in the station sets, the installer is not required to open
the station sets during installation or when implementing neu
services or features. The wiring from the KSU to the station
sets is accomplished with standard 4-wire Don-twisted 22 A~G
wire, which may be run for distances over 3,000 feet, and is
connected by modular plugs and jacks. All of these adt~antages
are yielded by the use of a solid state, distributed space di~-
ision matrix with time-division distributed control. Specifi-
11787;~2
cally, all of the logic functions for a given station are per-
formed bv the station set circuit and the associated station
card circuit. ~hus, a logic failure in one station card cir-
cuit will affect onlv the associated station, and repair or
replacement of the failed station card circuit may be effected
without interrupting or interfering with service on any other
line.
Referring specifically to Figue 3, the station card
circuit 200 shown there includes transformers 202 and 204,
which are connected to the A path (conductors 206 and 208)
and the B path (conductors 210 and 212), respectively. The
phantom path is connected from the center-tapped windings of
transformers 202 and 204 to the data transceiver 214, which is
fullv described in co-pending patent application Serial No.
319,744 and Serial No. 304,660. The data received from the
associated station set circuit 100 via the phantom pair is fed
in a continuous stream from the data transceiver 214 to the
microcomputer 216, which decodes the data. The microcomputer
216 is preferably the Part No. R6500/1 single-chip micro-
computer system manufactured by Rockwell International Cbrpora-
tion. When the data received from the associated station set
100 includes a word having a bit which is indicative that a
particular button has been depressed by the user of thestation
set, the microcomputer 216 generates the outPuts necessary to
implement the service or feature associated with that button.
For example, if a C.O. line is to be seized, an appropriate
output is fed from output terminal A5 of microcomputer 216 to
the current generator 218, which is a digital-to-analogo~nver-
ter formed by four operational amplifiers with their output
terminals ties so as to sum their respective outputs. In
response, the current generator 218 ~enerates a predetermined
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DC output current (1.6 ma) which is 6uperimposed upon any signal
received from the station set on the A path fed through
transformer 202 and DC blocking capacitance 220. Both the out-
put of current generator 218 and the signal received via the A
path are transmitted to the crosspoint array 222, which consists
of a number of ~OSFETs, each having its source electrode conn-
ected either to an associated line card circuit, or to a link
card circuit, or to a page card circuit, or to another station
card circuit, or to a conierence card circuit, all of the drain
electrodes being connected in common to the outputs of current
generator 218 and transformer 202. Each of the gate electrodes
of the MOSFETs is connected to an associated crosspoint latch
in the array of crosspoint latches 224, which consists of demul-
tiplexers formed by three eight-bit latches (CD4099BE). The
array 224 receives three continuous data streams from micro-
computer 216; latch command data, which is issued to all of the
crosspoint latches and consists of a one bit command (O or 1~;
write enable strobe data, which identifies which of the eight-
bit latches is to receive the latch command data; and address
data which identifies with a three-bit address that latch in
each package which is to receive the latch command data. When
the proper conjunction of inputs causes one of the crosspoint
latches 224 to close, the associated ~OSFET crosspoint in array
222 is biased conductive to close the audio path from A-pair
206, 208 through transformer 202, DC blocking capacitance 220
and the drain and source electrodes of the conductive ~OSFET
in array 222. A dial disable circuit 226 formed by a saturating
operational amplifier receives inputs from only those cross-
point latches 224 associated with crosspoints which are conn-
ected to line cards; those inputs are indicative of the statusof those latches, and when any such latch is closed, circuit
11
~1787Z;~
226 responds by terminating the dial disable output signal
which is normally fed to negative impedance circuit 228 and
to function multiplexer 230. Removal of the dial disable
signal activates the negative impedance 228 from an open
circuit condition to a first level of -600 ohms so as to match
the impedance in the station card 200 to the impedance to
which connection has been made via the conductive MOSFET
crosspoint. The function multiplexer 230, formed by a tree
of analog gates (a single CD4051BE) which receives a four-bit
address from the microcomputer 216, also receives a number of
simultaneous inputs including the presence or absence of a
dial disable signal, the presence or absence of a hands-free
disable signal, and slow-flashing and quick-flashing visual
indicator signals. These ~imultaneous inputs are time-division
multiplexed to form the input to terminal B7 of microcomputer
216, and are thus available for inclusion in the data stream
output at terminal D3 to the data transceiver 214. The array of
digital crosspoints 232 are, like the function multiplexer 230,
formed by a tree of analog gates (also a ~ingle CD4051BE) which
receives a four-bit address from the microcomputer 216, and also
receives a serles of simultaneous inputs in the form of voltages
indicative of the status (seizable, not seizable, etc) of the
passive ports to which the crosspoints 222 are connected. Each
of the analog crosspoints 222 is thus paired with one of the
digital crosspoints 232 to form an active port. The simultan-
eous inputs to digital crosspoints 232 are time-division multi-
plexed and output to the voltage discriminator 234 formed by
three analog-to-digital converters which provide a three-bit
message to the microcomputer 216 at terminals BO,Bl and B6.
3~ Viewing the inputs to these terminals at any point in time, if
none of the three voltage reference levels of discriminator 234
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is exceeded by the signal voltage (+2v, Ov, -2v or -4v) sampled
by digital crosspoint 232, then logic O appears at each of the
terminals BO, Bl and B6, indicating to the microcomputer 216
that the passive port being interrogated at that point in time
is seizable and its associated visual indicators in the station
sets are off. If the first voltage reference level is exceeded,
a logic 1 appears at B6 and logic O appears at BO and Bl, in-
dicating that the passive port being interro~ated at that point
in time is seizable, but its associated visual indicators are
on, indicating that the station card incorporating the inter-
rogated passive port is in use on its A-pair. If the second
voltage reference level is exceeded, a logic 1 appears at B6
and BO and a logic O appears at Bl, indicating that the passive
port being interrogated at that point in time is not seizable,
except by an active port with a pre-emptive seize capability,
and its associated visual indicators are on. If the third vol-
tage level is exceeded, a logic 1 appears at B0, B1 and B6,
indicating that the passive port being interrogated at that
point in time is not seizable by any active port, i.e., it has
been pre-emptively seized, and its associated visual indicators
are on. If the passive port of a line card being interrogated
at any point in time indicates that it is either receiving an
incoming call on the associated C.O. line, or is on HOLD, i.e.,
when the voltage signal input to data crosspoints 232 alternate
between Ov and +2v, this flashing signal will be sampled by the
associated digital crosspoint in array 23~and will be passed
through voltage discriminator 234 to terminal B6 as a series of
logic ls alternating with a series of logic Os at the rate and
duty cycle of the flashing signal being sampled. All of this
information is employed by the microprocessor 216 to determine
whether to signal the current generator 218 to send signal cur-
13
~17~72Z
rent on the audio path via a conductive ~OSFET crosspoint to a
passive port, and to signal the station sets from terminal D3
via data transceiver 214 as to the status of all the interroga-
ted passive ports.
If and only if a requested telephone ser~ice or feature
is indicated as being ~vailable upon interrogation of the rele-
vant passive port, signal current will be generated by the
active port to advise the passive port of its seizure and the
desired service. Specifically, the current generator 218 can
receive any one of four command signals from microcomputer 216
in response to data received at terminal AO. Absent any command
signal, the output from current generator 218 is nil (O ma). A
seize signal may appear at terminal A5, causing a seize current
(1.6 ma) to flow from current generator 218 on the audio path
and through a conductive MOSFET crosspoint to the passive port
to which that crosspoint is connected. That passive port is
thus informed that it has been seized, and it responds by gen-
erating a voltage signal which is transmitted to all of the
active ports to which the passive port is connected to indicate
to those active ports that it has been seized. A conference
signal may appear at terminal A6, causing a double seize current
(3.2 ma) to flow from current generator 218 to signal seizure
of two passive ports, e.g., conferencing two incoming C.O. lines.
The seized passive ports respond by each generating a voltage
signal indicative of seizure. The conference signal from ter-
minal A6 of microcomputer 216 is also input to negative imped-
ance 228 to adjust its value to -200 ohms so as to match the
impedance of the two conferenced lines to which the station card
has been connected through the seized passive ports. A flash
signal may appear at terminal A7 of microcomputer 216, causin~
14
li7872Z
a flash current (6.4 ma) to flow from current generator 218 and
break the loop current on a seized CØ line while continuing to
hold that line. Hold and privacy release signals may appear
at terminal A4 of microcomputer 216, causing either a hold cur-
rent pulse (14 ma) of brief duration to be generated, or a pri-
vacy release current pulse (14 ma) to be generated as long as
the privacy release button in the associated station set is
depressed. ID response to the aforementioned signals currents
from current generator 218, the KSU circuit incorporating the
receiving passive port implements the requested service indica-
ted by the signal current level, and the receiving passive port
generates a voltage signal indicative of its seizure.
Each ~tation card 200 includes one or more passive
ports, viz., a hotline B-port 238, a link B-port 240, or a page
input to B-port ~witching circuit 246. The te~l "B-port"
refers only to station card passive ports, which provide access
to the B-pair communication channel. In the system shown in
Figure 1, the station cards require no link B-ports 240, since
there are no links. If tbe optional paging and background
music features are eliminated, the PAGE and BG~ input circuits
in B-port switching circuit 246 may be eliminated. There are
multiple connections to the hotline B-port from one active port
in each of the other station cards in this system. In the
system shown in Figure 2, each station card has a link B-port
which may be seized by a link card circuit. The hotline B-port
is connected to one active port in only one other station card
200; if a system is desired in which all internal calling is to
be accomplished through the link cards, the hotline B-port may
be eliminated. As in the system of Figure 1, if the optional
paging and background music features are eliminated, the PA OE
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and BGM input circuits in B-port switching circuit 246 may be
eliminated. These B-port circuits are shown in detail in Fig-
ure 4. The hotline B-port ~38 col~prises a transformer 250 for
isolating the DC current signals, which are received from the
active ports to which transformer 250 is connected via the HLB
ANALOG conductor, from the VOICE or AUDIO PATH. A resistor 252
is connected across the DC signal-current-receiving winding
of transformer 250 for the purpose of providing a shunt path
past that winding so as to minimize transients induced in the
other winding by the DC current signals, and an impedance-
matching resistance 254 of equal value is connected across the
other winding. A signal current sensor circuit comprises tran-
sistor 256, which is biased by -9v. applied through resistor
260 to its base, which is also connected to the anode of diode
258, the cathode of which is grounded. The collector is conn-
ected through parallel resistor 262 and capacitor 264 to -9v.,
and the emitter is connected through resistor 252 and its
parallel winding of transformer 250 to the HLB ANALOG conductor.
A seize signal current (1.6 ma) is detected as an increase in
the voltage across resistor 262, which causes voltage compar-
ator 266 to generate a HL SEIZE 2 signal which is transmitted
to input terminal B5 of microcomputer 216. A latch command is
then generated in the data stream from terminal ~5,causing the
pertinent one of function latches 236 (Figure 3) to close and
thereby issue the HL CONTROL 2 signal (logic 1) to digital-to-
analog converter 261 in hotline B-port 23~. In response, the
D/A converter 261 generated an output which is applied through
resistor 263 to voltage follower 269, which generates a ~C
signal voltage indicating seizure (-2v.) which is transmitted
to the digital crosspoint(s) of the active ports to which hot-
line B-port 238 is connected. The microcomputer 216 further
16
li787Z,'Z
responds to the HL SEIZE 2 or 3 signals by simultaneously gener-
ating a SPLASH TONE ENABLE sigDal at terminal A1, thereby
triggering splash tone control circuit 294 which then turns on
JCT FET 293 for about 1 second to pass the steady SPLASH TONE
signal received from tone generator circuit 500 to the AUDIO
PATH, thereby signalling the called party that there is an
incoming call. The SPLASH TONE ENABLE signal is also applied
as an input to inverting OR gate 290, which responds by turning
off JCT FET 23~ to block any PAGE or BGM transmission. The
microcomputer 216 responds to the depression of the appropriate
buttons at the called party's station set by generating the HL
B ENABLE signal at terminal D1, which turns on ~OSFET 2~8 in
seize control circuit 242 and is also applied as an input to
inverting OR gates 290 and 286 in B-port switcl~ing circuit 246,
thereby turn~g off both JCT FET 289 and ~OSFET 287 to block
PAGE and BGM transmissions, and causing inverter 285 to turn
on MOSFET 284 in the VOICE or AUDIO PRTH. Thus, a path is
closed for the transmission of voice signals via transformer
250, MOSFET 268, attenuator 244 formed by a resistive pi network
and MOSFET 284 through DC blocking capacitor 248 and trans-
former 204 to the B-pair communication channel comprising con-
ductors 210 and 212.
With a seized DC signal voltage (-2v.) at the output of
voltage follower 269, the hotline B-port 238 may be pre-emptively
seized by an active port having that ability. If a pre-emptive
seize current signal (3.2 ma) is received by h~tline B-port 238,
voltage comparator 263 generates a HL SEIZE 3 signal which is
fed to function multiplexer 23~. A latch command is then
generated in the data stream from terminal D5, causing the per-
tinent one of the array of function latches 236 (Figure 3) to
issue the HL CONTROL 3 signal to digital-to-anaiog converter 25~.
17
11787Z;~
In response, the D/A converter 257 generates an output ~hich is
applied through resistor 259 to voltage follower 269, which gen-
erates a DC signal voltage indicating pre-emptive seizure (-4~ ).
If the user of the associated station set 100 is utilizing the
A-pair communication channel, the microcomputer will generate
a HL CONTROL 1 signal (logic 1) at terminal DO, thereby causing
digital-to-analog converter 265 to generate an output through
resistor 267 which causes voltage follower 26~ to generate a
DC signal voltage (Ov.) indicating that the hotline B-port 238
is seizable and that the associated visual indicator in the call-
ing party's station set is tD be ~ t If each of the signals HL
CONTROL 1,2,3 is a logic 0, the voltage follower 269 ~ill gen-
erate a DC signal voltage (+2v.) indicating that the hotline
B-port 238 is seizable and that the associated visual indicator
in the calling party's station set is not to be lit.
The link B-port 240 comprises an isolating transformer
270 with DC shunt resistor 272 connected across the DC signal
current-receiving winding, and an impedance-matching resistor
274 connected across the other winding. A combination current
sensor and voltage sender circuit is formed by transistor 275,
operational amplifier 276, and the parallel-connected resistor
277 and capacitor 278. A DC current signal received on the
LINK conductor from an active port is sensed as an increase in
voltage across resistor 277, which in turn causes comparator
279 to generate a LINK SEIZE signal which is applied to terminal
L2 of microcomputer 216. If the call is received handsfree
at the called speakerphone, the microcomputer 216 also gen-
erates a SPLASH TONE ENABLE signal at terminal Al in response
to the LINK SEIZE signal, thereby triggering splash tone control
circuit 294 which then turns on JCT FET 293 for about 1 second
to pass the steady SPLASH TONE signal to the AUDIO PATH. The
18
117~37Z~
SPLASH TONE ENABLE signal is also applied as an input to in-
verting OR gate 290, which responds by turning off JCT FET 289
to block any PA~E or BGM transmission. If the seizing link
sends DC signal current (3.2 ma) indicating an intercom ringing
call, i.e., one which is to be answered via the handset hybrid
circuit instead of the speakerphone at the called station, then
voltage comparator 280 will also generate an output, which is
fed to terminal B3 of microcomputer 216 as an IC~ RING CALL
signal. In response, the microcomputer 216 generates a latch
command at terminal D5 instead of a SPLASH TONE ENABLE signal
at terminal A1. The latch command is fed to the function lat-
ches 236 (Figure 3) along with address data and write enable
stiobe data. Function latches 236 are formed by one eight-bit
latch (CD4099BE) which acts as a demultiplexer of the three
streams of received data in the ~ame manner as crosspoint
latches 224. In response to the aforementioDed latch command,
an IC~ RING TONE ENABLE 6ignal i~ geDerated and fed to B-port
switching circuit 246 (1) to turn on JCT FETs 288 and 296 to
allow passage of ICM RING TONE to the called party through
normally-conductive MOSFET 287 and to the calling party through
transformer 270 in the link B-port 240, and (2) to turn off JCT
FET 289 through inverting OR gate 290 to block any PAGE or BG'l
transmission.
Vpon termination of either the SPLASH TONE ENABLE sig-
nal or the ICM RING TONE ENABLE signal, a LINK ENABLE signal
is generated at terminal D2 of microcomputer 216 to turn on
~OSFET 283 in seize control circuit 242. The LINK ENABLE sig-
nal is also applied as an input to inverting OR gate 286 in
B-port switching circuit 246, thereby turning on MOSFET 287 and
causing inverter 285 to turn on MOSFET 284. Thus, a path is
closed for the transmission of voice signals via transformer
1~
~7~7Z;~
270, ~OSFET 283, attenuator 244, and ~OSFET 284 to the B-pair
communication channel. The LINK SEIZE signal is also applied
to the positive input terminal of operational amplifier 276
' connected as a voltage follower with its negative input and
its output tied to the emitter and base, respectively, of
transistor causing its emitter to 275 become more positive.
Thus, a DC voltage signal (-2v.) indicating seizure is generated
at the emitter of transistor 275 and is applied through resistor
272 and its parallel winding of transformer 270 to the LINK
conductor for transmission to the link.
If a call coming in to link B-port 240 is answered
at an alternate station set by dialing the called station set
extension number with aprefix code number, the alternate station
set is connected to the seizing link through the link B-port
240 of the called station set. Under these conditions, the
seizing link will generate a call steal DC current signal
(3.2 ma) which causes comparator 281 to generate on output
which is fed to terminal B4 as a CALL STEAL signal in response
to which the microcomputer 216 prevents user access to the
B-pair communication channel of the called station set. The
CALL STEAL signal is also applied to the call steal timer
circuit 282 to reset it. The call steal timer circuit starts
to run for a predetermined period of time (e.g., 30 seconds)
whenever it receives a LINK SEIZE signal, and while it is
running it biases the positive input terminal of operational
amplifier 276 so as to allow the generation of a DC voltage
signal at the emitter of transistor 27~ indicating seizure of
the link B-port, thereby enabling the call from the link to be
"stolen" ~y pre-emptively seizing the link B-port 240 via an
active port in an alternate station set. The call steal timer
~1787ZZ
circuit is also reset by the LINK ENABLE signal from terminal
D2 of the microcomputer 216 so as to prevent an answered call
from being "stolen", thereby preserving the called user's pri-
vacy.
The PAGE and BGM signals are received from the page
and tone cards, respectively, and are controlled by JCT FETS 291
and 292, respectively, which are normally conductive when PAGE
ENABLE and BGM ENABLE signals are applied to their respective
gate electrodes. These enabling signals are generated by func-
tion latches array 236 in response to latch commands issued atterminal D5 of microcomputer 216 in response to data received
at terminal A0 from the associated station set 100. A combin-
ation on/off/volume switch in the station set 100 controls the
generation of the BGM ENABLE signal by the associated station
circuit 200; when the switch is off, the signal will not
be generated, and when the switch is on, the signal will be gen-
erated. The PAGE ENABLE signal will normally be generated in
each station circuit 200, but will be terminated upon seizure
of the page card through a link card or directly from the
station card in response to requests from the station set.
CO AUDIBLE is a signal which is continuously generated
within the EKTS on the tone card 500 (Figure 6) for trans-
mission to the internal speaker in the station set upon receipt
of a C.O. AUDIBLE ENABLE signal at the gate electrode of JCT FET
295. These enabling signals are also received from the tone
card 500 in response to INCOMING CALL ENABLE signals generated
by the various line cards 300 (Figure 5) in response to a
ringing signal from the Central Office.
The program listing which follows on pages 23-46 is the
sequence of instructions stored in microcomputer 216 of each
117872;~
station card 200 (Figure 3). Each ROM address (LOC) with
machine operation code (CODE) followed by the assembly language
instruction of the program is included in the listing. The
assembly language instructions are explained in detail in the
manufacturer's Data Sheet entitled "Part No. R6500/1 Nicrocom-
puter System", Document No. 29000D51, Revision 2, dated October
1978 and published by the Rockwell International Corporation.
The Symbol Table on pp. 47-48 includes four columns of program
symbols on each page, with the value of each symbol listed at
the right side of each symbol.
22
11787Z;2
LARGE SYSTEM 2/28/79 BELOW 2K....... PAGE 0001
LINE # LOC CODE LINE
0002 0000 *=$0800
0003 0800 FUNMUX ~$0002
0004 0800 HFENAB -$0003
0005 0800 LNKMUX -$0005
0006 0800 MUX-$002E
0007 0800 WD0-$0006
0008 0800 WD]-$0007
0009 0800 WD2-$0008
0010 0800 WD3-$0009
0011 0800 WD4e$000A
0012 0800 WD5'$000B
0013 0800 WD6-$000C
0014 0800 WD7-$000D
0015 0800 WD8'$000E
0016 0800 WD9~$000F
0017 0800 WD10-$0010
0018 0800 WDI18$0011
0019 0800 WD12-$0012
0020 0800 WD13~$0013
0021 0800 WD14 e$00 14
0022 0800 WDI Se$00 15
0023 0800 WD16'$0016
0024 0800 WD17~$0017
0025 0800 WD18=$0018
0026 0800 WDl9-$0019
0027 0800 WD20'$00lA
0028 0800 WD21-$001B
0029 0800 WD22-$001C
0030 0800 WD23-$00ID
0031 0800 WD24'$00lE
0032 0800 WD25'$00IF
0033 0800 WD26-$0020
0034 0800 WD27~$0021
0035 0800 WD28-$0022
0036 0800 WD29-$0023
0037 0800 WD30-$0024
0038 0800 WD31'$0025
0039 0800 KYHOLD - WD7
0040 0800 KYPREL - WDII
0041 0800 KYHFRE - WDI9
0042 0800 KYANS - WDI9
0043 0800 KYPAGE - WD30
OU44 0800 KYCONT - WD27
0045 0800 KYFLS8 - WD15
0046 0800 KYSPU - WD3
0047 0800 KYBPSS ' WD2
0048 0800 KYHKSW - WD0
0049 0800 STUSI - $0031
0050 0800 STUS'$0026
0051 0800 INDX5-$0028
0052 0800 INDX4'$0027
0053 0800 FNMXI-$0029
0054 0800 TTMR'$002A
0055 0800 INDXI~$002B
0056 0800 INDX23$002C
1171~ Z
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0002
LINE # LOC CODE LINE
0057 0800 CURSTA'$002D
0058 0800 PT32A'$80
0059 0800 DIPT3A-$81
0060 0800 PT32B'$82
0061 0800 DIPT3B-$83
0062 0800 PT22A-$CI
0063 OB00 DIPT2A-$C3
0064 0800 PT22B-$CO
0065 0800 DIPT2B'$C2
0066 0800 ULTCH-$C7
0067 0800 LLTCH-$C6
0068 0800 VPCT-$C5
0069 0800 LOWCT-$C4
0070 0800 LDLTCH-$C5
0071 0800 TICT-$Cl
0072 0800 CLINTI-$C0
0073 0800 TIFL-$CD
0074 0800 INTBT'$CE
0075 0800 ARC-$CB
0076 0800 PRC-$CC
0077 0800 MSCTR -$32 ;MASTER LOOP COUNTER
0078 0800 D8 PWON CLD ; CLEARS DECIMAL MODE
0079 0801 A2 3F RESET LDX #$3F
0080 0803 9A TXS
0081 0804 A9 00 ZROLP LDA #$00
0082 0806 95 00 STA $00,X
0083 0808 CA DEX
0084 0809 10 F9 BPL ZROLP
008' 080B E8 INX ;X-0
0086 080C 86 2B STX INDXI ;SET UP INDEX POINTERS
0087 080E A9 40 LDA #$40 ;FOR INDIRECT MODE
0088 0810 85 2C STA INDXI+]
0089 0812 BD 01 09 RSTLP LDA SUPTBL,X
0090 0815 BC 02 09 LDY SUPTBL+I,X
0091 0818 91 2B STA (INDXI),Y;WRITE PORT CONTROL BITS
0092 08IA E8 INX
0093 081B E8 INX
0094 081C E0 18 CPX #ENDTBL-supTBL+l~ALL DONE?
0095 08lE D0 F2 BNE RSTLP
0096 0820 58 CLI
0097 0821 A9 40 LDA #$40 ; SETS RELEASE REQ. TO INIT.
XPOINTS
0098 0823 85 26 STA STUS
0099 0825 20 6C 08 SYNC JSR OVTHI
0100 0828 A9 08 LDA #$08
0101 082A 05 80 ORA PT32A
0102 082C 85 80 STA PT32A ; SYNC PULSE HIGH
0103 082E A2 00 LDX #$00
0104 0830 ; ZERO X REGESTER (WD CTR)
0105 0830 20 79 08 JSR INITDL
0106 0833 A9 F7 LDA #$F7
0107 0835 25 80 AND PT32A
0108 0837 85 80 STA PT32A ; SYNC PULSE LOW
0109 0839 20 86 08 JSR SYLPl ;WAIT FOR "I"
0110 083C A9 7F SYCTl LDA #$7F
0111 083E 85 CE STA INTBT
:~1787;~Z
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0003
LINE i~ LOC CODE LINE
0112 0840 20 C3 08 JSR SYBY
0]13 0843 20 B6 08 JSR SYLPI ;WAIT FOR "2"
0114 0846 20 E7 OD JSR BPORT
0115 0849 20 40 OF JSR SHSH
0116 084C A5 31 LDA STUSI
0117 084E 29 FC AND #$FC
0118 0850 85 31 STA STUSI
0119 0852 24 CD SYNCIA BIT TIFL
0120 0854 50 FC BYC SYNCIA
0121 0856 A5 C4 LDA LOWCT
0122 0858 20 73 08 SYNC2 JSR OUTLO
0123 085B A9 02 LDA #$2
0124 085D 85 2A STA TTMR ;REPAIR TTMR
0125 085F A9 90 LDA #$90
0126 0861 A0 00 LDY #$00
0127 0863 20 BA 08 JSR SYLP2
0128 0866 20 DE 08 SYNC5 JSR TTIME
0129 0869 4C 19 09 JMP START
0130 086C A9 F7 OUTHI LDA #$F7 ;SIGNAL GOES TO -5V (DATA I
LEVEL)
0131 086E 25 C0 AND PT22B
0132 0870 85 C0 OUTHI0 STA PT22B
0133 0872 60 RTS
0134 0873 A9 08 OUTLD LDA #$08 ;SIGNAL GOES TO GND (DATA O
LEVEL)
0135 0875 05 C0 ORA PT22B
0136 0877 D0 F7 BNE OUTHIO ;BRANCH ALWAYS
0137 0879 A9 99 INITDL LDA #<DIALSTj**INSERT VECTOR LO ADDR**
0138 087B 48 PUA
0139 087C A9 08 LDA #>DIALST;**INSERT VECTOR HI ADDR**
0140 087E 85 28 INIT STA INDX5
0141 0880 68 PLA
0142 0881 85 27 STA INDX4
0143 0883 A9 EE LDA #$EE ;IRQ ON NEG. TRANS
0144 0885 85 CC STA PRC
0145 0887 A5 CD INTEA LDA TIFL ;CLEARS INT FLAG REG
0146 0889 A9 82 LDA #$82 ;SETS CAI INT.ENABLE
0147 088B 85 CE STA INTBT
0148 088D 60 RTS
0149 088E A9 A6 INITRP LDA#<RESPST ;**INSERT VECTOR LO ADDR**
0150 0890 48 PHA
0151 0891 A9 08 LDA #>RESPST;**INSERT VECTOR HI ADDR**
0152 0893 4C 7E 08 JMP INIT
0153 0896 6C 27 00 DINT JMP (INDX4)
0154 0899 48 DIALST PHA
0155 089A A9 FE LDA #$FE ;INDEXED TO START HERE FOR DIAL
0156 089C 25 80 AND PT32A
0157 089E 85 80 STA PT32A
0158 08A0 E6 26 INC STUS
0159 08A2 A5 CI INTRTN LDA TICT ;CLEARS IFR
0160 08A4 68 PLA
0161 08A5 40 RTI
0162 08A6 48 RESPST PHA
0163 08A7 46 26 LSR STUS ;INDEX HERE FOR RESPONSE
0164 08A9 38 SEC
0165 08AA 26 26 ROL STUS ;SET LSB STUS
0166 08AC D0 F4 BNE I~TRTN ;BRANCH ALWAYS
117872'~
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0004 :.
LINE # LOC CODE LINE ;
0167 08AE A9 00 TIP5T LDA #$00 .
0168 08B0 85 2A STA TTMR ; ~$~
0169 08B2 A9 C8 LDA #$C8
0170 08B4 D0 OA BNE STLLTH
0171 08B6 AS 40 SYLPI LDA #$40 ;GET LSB
0172 08B8 A0 02 LDY #$2 ;GET MSB
0173 08BA 24 CD SYLP2 BIT TIFL ;WAIT FOR TIMEOUT
0174 08BC 50 FC BVC SYLP2
0175 08BE 84 C7 STLTCH STY ULTCH ;SET UPPER LATCH
0176 08C0 85 C6 STLLTH STA LLTCH
0177 08C2 60 RTS
0178 08C3 A5 26 SYBY LDA STUS
1079 08C5 6A ROR A
0180 08C6 B0 06 BCS SYBYI
0181 08C8 A9 01 LDA #$01 ; SET LSB
0182 08CA 05 80 ORA PT32A
0183 08CC 85 80 STA PT32A
0184 08CE 46 26 SYBYI LSR STUS
0185 08D0 18 CLC
0186 08D1 26 26 ROL STUS
0187 08D3 60 RTS
0188 08D4 A0 09 DLYQ LDY#$09 ;TIME DELAY OF 72 CYCLES
0189 08D6 D0 02 BNE DLY0
0190 08D8 A0 07 DLY2 LDY #$07 ;TIME DELAY OF 57 CYCLES
0192 08DA 88 DLY0 DEY
0192 08DB DO FD BNE DLY0
0193 08DD 60 RTS
0194 08DE 24 CD TTIME BIT TIFL
0195 08E0 50 FC BYC TTIME
0196 08E2 E6 2A INC TTMR
0197 08E4 A5 C4 LDA LOWCT
0198 08F,6 A5 2A LDA TTMR
0199 08E8 C9 03 CMP #$3
0200 08EA F0 C2 BEQ TIP5T
0201 08EC C9 01 CMP #$01 ;START OF T3?
0202 08EE F0 07 BEQ T2PST ;SET LATCH=2*T
0203 08F0 A9 81 TIT LDA #$81
0204 08F2 A0 00 LDY #$00
0205 08F4 4C BE 08 JMP STLTCH
0206 08F7 A9 77 T2P5T LDA #$77 ;SET UP 2-05$Q@ELoUT
0207 08F9 A0 01 LDY #$01
0208 08FB 4C BE 08 JMP STLTCH
0209 08FE FO ADSTB .BYT $F0 ;STROBE ADDI
0210 08FF E8 .BYT $E8 ; ADD2
0211 O900 D8 .BYT $D8 ; ADD3
0212 0901 7F SUPTBL .BYT $7F
0213 0902 CE .BYT <INTBT ;CLEAR INT. ENAB.REG
0214 0903 40 .BYT $40
0215 0904 CB .BYT <ARC ;INITIALIZE AXIL CONTROL REG.
0216 0905 EF .BYT $EF
0217 0906 CC .BYT<PRC ;INITIALIZE PERIF.CONTROL
REGISTER
0218 0907 48 .BYT $48
0219 0908 C6 .BYT<LLTCH ;TIMER COUNTDOWN IN HEX(MICRO
SEC)
0220 0909 00 .BYT $UU
0221 090A C5 .BYT <LDI.TCH;TIMER HIGH BYTE
26
il787Z~
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0005
LINE # LOC CODE LINE
0222 090B FF .BYT $FF
0223 090C C3 .BYT <DIPT2A ;SET OUTPUTS
0224 090D FF .BYT $FF
0225 090E C2 .BYT <DIPT2B
0226 090F FF .BYT $FF
0227 0910 81 .BYT <DIPT3A
0228 0911 C8 .BYT $C8
0229 0912 Cl .BYT <PT22A ;INITIALIZE MUX LINES
0230 0913 D8 .BYT $D8
0231 0914 C0 .BYT <PT22B ;INITIALIZE MUX AND ENABLE
LINES
0232 0915 03 .BYT $03
0233 0916 80 .BYT <PT32A ;INITIALIZE CURRENT GEN. &
1/0
0234 0917 DD .BYT $DD
0235 0918 CO ENDTBL .BYT <PT22B
0236 0919 20 6C 08 START JSR OUTHI
0237 091C E0 IF CPX #$1F ;WD31-WD0
0238 09IE D0 07 BNE I.SMX
0239 0920 A4 05 LDY LNKMUX
0240 0922 B9 93 09 LDA ATBLI,Y
024] 0925 85 2E STA MUX
0242 0927 A5 2E LSMX LDA MUX
0243 0929 4A LSR A
0244 092A 4A LSR A
0245 092B 4A LSR A
0246 092C 29 07 AND #$7 ;MASK MUX BITS
0247 092E A0 00 LDY #$0 ;SET UP Y FOR TABLE LOOKUP
0248 0930 24 2E BIT MUX ;PREPARE TO COMPUTE Y INDEX
0249 0932 70 03 BVS ADD2
0250 0934 10 02 8PL ADDI
0251 0936 C8 ADD3 INY
0252 0937 C8 ADD2 INY
0253 0938 19 FE 08 ADDI ORA ADSTB,Y
0254 093B 85 Cl STA PT22A
0255 093D 20 DE 08 JSR TTIME
0256 0940 B5 06 LDA WD0,X
0257 0942 30 03 BMI MRGI
0258 0944 20 73 08 SHORT JSR OUTLO
0259 0947 20 79 08 MRGI JSR INITDL
0260 094A 20 DE 08 LOPI JSR TTIME
0261 094D A9 7F CTUI LDA #$7F
0262 094F 25 CE AND INTBT
0263 0951 85 CE STA INTBT
0264 0953 20 73 08 JSR OUTLO
0265 0956 20 C3 08 JSR SYBY
0266 0959 20 8E 08 JSR INITRP
0267 095C 20 D8 OD JSR WSRF
0268 095F 20 DE 08 JSR TTIME
0269 0962 A9 7F CTU2 LDA #$7F
0270 0964 85 CE STA INTBT
0271 0966 A5 26 LDA STUS
0272 0968 4A LSR A
0273 0969 B0 IA BCS INCT ;BRANCH IF INT. OCCURRED
0274 096B 20 97 09 JSR TCTR3 ;TEST FOR RESP. CTR'3?
0275 096E F0 05 BEQ CTU4 ;BRANCH IF - 3
0276 0970 A9 F8 LDA #$F8 ;ZERO CTR.
i~7~7Z'~
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0006
LINE # LOC CODE LINE
0277 0972 20 9E 09 JSR BITCLR
0278 0975 46 26 CTU4 LSR STUS ;RESET INTl FLAG
0279 0977 18 CLC
0280 0978 26 26 ROL STUS
0281 097A E0 lF CPX #$1F
0282 097C F0 04 BEQ SYNCA
0283 097E E8 INX
0284 097F 4C 19 09 JMP START
0285 0982 4C 25 08 SYNCA JMP SYNC
0286 0985 20 97 09 INCT JSR TCTR3
0287 0988 F0 EB BEQ CTU4
0288 098A C9 07 CMP #$07 ;TEST SERVICED BIT
0289 098C F0 E7 BEQ CTU4 ;BRANCH IF SERVICED
0290 098E F6 06 INC WD0,X ;INCREMENT RESPONCE CTR.
029] 0990 4C 75 09 JMP CTU4
0292 0993 B8 ATBLl .BYT CP24
0293 0994 A8 .BYT CP22
0294 0995 98 .BYT CP20
0295 0996 78 .BYT CP16
0296 0997 .FILE LSSUB/l
0297 0997 B5 06 TCTR3 LDA WD0,X ;TEST RESPONSE COUNTER-3?
0298 0999 29 07 CTR3 AND #$7
0299 099B C9 03 CMP #$3
0300 099D 60 DELY RTS
0301 099E 35 06 BITCLR AND WD0,X ;CLEAR BITS IN WD0 INDEXED
0302 09A0 95 06 BITOP STA WD0,X
0303 09A2 60 RTS
0304 09A3 ]5 06 BITSET ORA WD0,X ;SET BITS
0305 O9A5 DO F9 BNE BITOP ;BRANCH ALWAYS
0306 09A7 ; CONTROL FUNCTION LATCHES
0307 09A7 05 C0 STB32A ORA PT22B
0308 09A9 85 C0 STA PT22B
0309 09AB A5 80 LDA PT32A
0310 09AD 49 02 EOR #$2
0311 09AF 85 80 STA PT32A
0312 09B1 49 02 EOR #$2
0313 09B3 85 80 STA PT32A
0314 09B5 60 RTS
0315 09B6 ; SET OR CLEAR DATA LINE
0316 09B6 A5 C0 SDL LDA PT22B
0317 09B8 09 20 ORA #$20
0318 09BA D0 04 BNE DL0
0319 09BC A5 C0 CDL LDA PT22B
0320 09BE 29 DF AND #$DF
0321 09C0 85 C0 DL0 STA PT22B
0322 09C2 60 RTS
0323 09C3 . FILE LCOSEZ/I
0324 09C3 DELAY'$002F
0325 09C3 A4 26 COSZ LDY STUS ;TEST RELEASE BIT
0326 O9C5 30 2F BMI TNOF ;BRANCH TO TURN OFF
0327 O9C7 20 97 09 JSR TCTR3
0328 09CA F0 41 BEQ TNON ;-3
0329 09CC C9 01 CMP #$01
0330 09CE D0 OB BNE COSZ0
0331 O9D0 B5 06 LDA WD0,X
ii7~'7Z'~
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0007
LINE # LOC CODE LINE
0332 O9D2 29 20 AND #$20
0333 O9D4 DO 05 BNE COSZO
0334 O9D6 98 SRRBIT TYA ;SET REL REQ BIT CTR-l
0335 O9D7 09 40 ORA #$40
0336 O9D9 85 26 STA STUS
0337 O9DB B5 06 COSZO LDA WDO,X ;TEST I HOLD PROTECT BIT
0338 O9DD 2A ROL A
0339 O9DE 10 OD BPL IHPO
0340 OOEO A5 82 IHPI LDA PT32B ;FORCE DO INTO CARRY
0341 O9E2 4A LSR A
0342 O9E3 BO 05 BCS EXIT5
0343 O9E5 A9 BF LDA #$BF ;CLEAR I HOLD PROTECT BIT
0344 O9E7 20 9E 09 IHP JSR BITCLR
0345 O9EA 4C 6E OC EXIT5 JMP LAMP
0346 O9ED A5 82 IHPO LDA PT32B
0347 O9EF 4A LSR A
0348 O9FO 90 F8 BCC EXIT5
0349 O9F2 A9 B7 LDA #$B7 ;RESET I HOLD
0350 O9F4 DO Fl BNE IHP
0351 O9F6 20 97 09 TNOF JSR TCTR3 jTEST RESP. CTR-3?
0352 O9F9 DO 05 BNE ARCOS
0353 O9FB A9 04 LDA #$04 ;SET SERV BIT, &TRIG BIT
0354 O9FD 20 A3 09 JSR BITSET
0355 OAOO A9 DF ARCOS LDA #$DF ;RESET I SEIZE
0356 OA02 20 9E 09 JSR BITCLR
0357 OA05 98 TYA ;RESET CONF BIT + DIAL ENA REQ
0358 OA06 29 D7 AND #$D7
0359 OA08 85 26 STA STUS
0360 OAOA ; OPEN CROSS POINTS
0361 OAOA 4C F8 OB JMP OPENXP
0362 OAOD 98 TNON TYA ;GET STATUS
0363 OAOE 29 04 AND #$04 ;TEST OFF HOOK BIT
0364 OAIO FO D8 BEQ EXIT5
0365 OA12 A9 04 STSER LDA #$04
0366 OA14 20 A3 09 JSR BITSET ;SET SERVICED BIT
0367 OA17 A5 19 LDA KYHFRE
Q368 OAI9 30 CF 8MI EXIT5
0369 OAIB A5 82 LDA PT32B ;TEST Dl
0370 OAlD 4A LSR A
0371 OAIE BO CA BCS EXIT5 ;DI-l BUSY
0372 OA20 20 EC OA CLSXPT JSR IOFF ;TURN OFF IGEN
0373 OA23 20 4E OA JSR CLOSEX ;TOGGLE CRSPT ENB
0374 OA26 98 TYA ;GET STATUS
0375 OA27 29 20 AND #$20
0376 OA29 FO OF BEQ SCBT,BRA CONF BIT NOT SET
0377 OA2B B5 06 LDA WDO,X
0378 OA2D 29 08 AND #$08
0379 OA2F FO B9 BEQ EXIT5;RIVERSIDE
0380 OA31 98 TYA ;RESET DIAL ENAB REQ BIT
0381 OA32 29 F7 AND #$F7
0382 OA34 85 26 STA STUS
0383 OA36 A9 40 LDA #$40 ;CONF ON
0384 OA38 DO 02 BNE COSZ] ;BRANCH ALWAYS
0385 OA3A A9 20 SCBT LDA #$20 ;SEIZE ON ONLY
0386 OA3C 20 82 OA COSZI JSR IPORT
il7~7ZZ
LARGE SYSTEM 2/28/79 BELOW 2K!........ PAGE 0008
LINE # LOC CODE LINE
0387 OA3F 98 TYA ;SET CONF. BIT + DIAL ENA REQ
+ SEIZE BIT
0388 OA40 09 38 ORA #$38
0389 OA42 85 26 STA STUS
0390 OA44 A9 20 LDA #$20 ;SET I SEIZE BIT
0391 OA46 15 06 ORA WDO,X
0392 OA48 ~9 F7 AND #$F7 ;CLEAR I HOLD BIT
0393 OA4A 95 06 STA WDO,X
0394 OA4C DO 9C BNE EXIT5
0395 OA4E A5 CO CLOSEX LDA PT22B ;SET XPT
0396 OA50 09 20 ORA #$20
0397 OA52 85 CO STA PT22B
0398 OA54 A5 Cl SXPT LDA PT22A ;READ MUX DATA
0399 OA56 49 38 EOR #$38
0400 OA58 29 38 ASXPT AND #$38 ;INVERT SELECT BITS
0401 OA5A 18 CLC
0402 OA5B 2A ROL A
0403 OA5C 2A ROL A
0404 OA5D 2A ROL A
0405 OA5E BO OB BCS ROLOVR ;TEST FOR ENAB6
0406 OA60 48 STROBA PHA
0407 OA61 45 Cl EOR PT22A ;TOGGLE ENAB
0408 OA63 85 Cl STA PT22A
0409 OA65 68 PLA
0410 OA66 45 Cl EOR PT22A
0411 OA68 85 Cl STA PT22A
0412 OA6A 60 RTS
0413 OA6B A9 40 ROLOVR LDA #$40 ;SET ENAB6 MASK
0414 OA6D 48 STROBB PHA
0415 OA6E 45 CO EOR PT22B
0416 OA70 85 CO STA PT22B
0417 OA72 68 PLA
0418 OA73 45 CO EOR PT22B
0419 OA75 85 CO STA PT22B
0420 OA77 60 RTS
0421 OA78 .FILE LPRREL/I
0422 OA78 TMPI -$29
0423 OA78 A5 2D RESPRT LDA CVRSTA ;RESTORE PREVIOVS CURRENT VALUE
0424 OA7A 48 IIPORT PHA ;SAVE UPDATED CURRENT VALUE
0425 OA7B A9 OF LDA #$0F ;RESET CURRENT GENERATOR
0426 OA7D 25 80 AND PT32A
0427 Oa7F 85 80 STA PT32A
0428 OA81 68 PLA ;SET UPDATED CURRENT VALUE
0429 OA82 05 80 IPORTORA PT32A
0430 OA84 85 80 STA PT32A
0431 OA86 60 RTS ;END ISOLATE 1 PORT ROUTINE
0432 OA87 04 XREF .BYT WD4-WDO
0433 OA88 05 .BYT WD5-WDO
0434 OA89 06 .BYT WD6-WDO
0435 OA8A 08 .BYT WD8-WDO
0436 OA8B 09 .BYT WD9-WDO
0437 OA8C OA .BYT WDIO-WDO
0438 OA8D OC .BYT WD12-WDO
0439 OA8E OD .BYT WD13-WDO
0440 OA8F OE .BYT WD14-WDO
0441 OA90 10 .BYT WD16-WDO
~7872'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0009
LINE # LOC CODE LINE
0442 OA91 11 .BYT WD17-WDO
0443 OA92 ]2 .BYT WD]8-WDO
0444 OA93 14 .BYT WD20-WDO
0445 OA94 15 .BYT WD21-WDO
0446 OA95 ]6 .BYT WD22-WDO
0447 OA96 ]8 .BYT WD24-WDO
0448 OA97 19 .BYT WD25-WDO
0449 OA98 lA .BYT WD26-WDO
0450 OA99 lC .BYT WD28-WDO
0451 OA9A lD .BYT WD29-WDO
0452 OA9B ]E .BYT WD30-WDO
0453 OA9C ; PRIVACY RELEASE RTN
0454 OA9C
0455 OA9C
0456 OA9C ~4 11 PREL BIT KYPREL ;TEST PR TIMER BIT
0457 OA9E 70 36 BYS PTOUT ;BRANCH ON PR TIMER TIMEOUT
0458 O M 0 20 97 09 JSR TCTR3
0459 OAA3 DO 4C BNE PTSTR ;BRA ON CTR NOT EQU. TO 3
0460 OAA5 A5 80 LDA PT32A
0461 O M 7 29 20 AND #$20 ;ISOLATE SEIZE BIT
0462 OAA9 85 2D STA CURSTA
0463 O M B 4A LSR A ;SHIFT SEIZE BIT TO HOLD BIT
POSITION
0464 OAAC 20 7A OA JSR IIPORT
0465 OAAF A5 11 LDA KYPREL ;SET PREL TIMER START BIT
0466 OABl 09 24 ORA #$24 ;SET SERVICED BIT+TINER START
0467 OAB3 85 ]1 PSTH3 STA KYPREL
0468 OAB5 AO 09 LDY #$09
0469 OAB7 8A RELO TXA
0470 OAB8 48 PHA
0471 OAB9 4C CO OA JMP PSTHO
0472 OABC CO 09 PSIHLD CPY #$09
0473 OABE FO 13 BEQ PSTHl
0474 OACO BE 87 OA PSTHO LDX XREF,Y
0475 OAC3 B5 06 LDA WDO,X
0476 OAC5 29 20 AND #$20 ;IF I SEIZE BIT SET
0477 OAC7 FO 07 BEQ PSTH2 ;SET IHOLD PROTECT & IHOLD BITS
0478 OAC9 86 29 STX TMPl
0479 OACB A9 48 LDA #$48
0480 OACD 20 A3 09 JSR BITSET
0481 OADO 88 PSTH2 DEY
0482 OADI 10 E9 BPL PSIHLD
0483 OAD3 68 PSTHI PLA
0484 OAD4 M TAX ;RESTORE X
0485 OAD5 60 PMIDT5 RTS
0486 OAD6 A5 11 PTOUT LDA KYPREL
0487 OAD8 29 07 AND #$7 ;MASK CTR BITS
0488 OADA DO 10 BNE IOFF ;BRANCH ON CTR=O
0489 OADC 20 78 OA JSR RESPRT ;GO TO RESTORE PORT ROUTINE
0490 OADF A9 9F LDA #$gF ;ZERO PR TIMER ST+TIMEOUT
0491 OAEl 20 9E 09 JSR BITCLR
0492 OAE4 A4 29 LDY TMPI
0493 OAE6 A9 AO LDA #$AO
0494 OAE8 99 06 00 STA WDO,Y
0495 OAEB 60 RTS
0496 OAEC A9 00 IOFF LDA #So ;TURN OFF ALL CURRENT GENERATORS
1~787'~'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0010
LINE # LOC CODE LINE
0497 OAEE 4C 7A OA JMP IIPORT
0498 OAFI A5 ]] PTSTR LDA KYPREL ;TEST PREL TIMER START BIT
0499 OAF3 29 20 AND #$20
0500 OAF5 FO DE BEQ PMIDT5
050] OAF7 A9 67 LDA #$67 ;SET PRSB,PRTB,SB,RC=3
0502 OAF9 AO 15 LDY #$]5 ;SERVICE 2ND HALF CO SEIZE
0503 OAFB DO B6 BNE PSTH3
0504 OAFD .FILE LHLDSR/]
0505 OAFD ; HOLD SERVICE ROUTINE
0506 OAFD
0507 OAFD
0508 OAFD 24 02 HSRTN BIT FUNMUX ;TEST FUNMUX BIT 6
0509 OAFF 70 OC BVS DSSHLD
0510 OBOl A4 OD LDY KYHOLD
05]1 OB03 98 TYA
0512 OB04 29 20 AND #$20
0513 OB06 DO 05 BNE DSSHLD
0514 OB08 98 TYA
0515 OBO9 09 03 ORA #$3
0516 OBOB 85 OD STA KYHOLD
0517 OBOD 24 OD DSSHLD BIT KYHOLD ;TEST HOLD TIMER BIT
0518 OBOF 70 14 BVS HTOUT ;BRA ON HOLD TIMER TIMEOUT
0519 OBII 20 97 09 JSR TCTR3
0520 OB14 DO IB BNE HTSTR ;BRA ON CTR NOT EQU. TO 3
0521 OB16 A9 10 LDA #$10 ;TURN ON I HOLD
0522 OB18 20 82 OA JSR IPORT
0523 OBIB 98 TYA ;SET HOLD TIMER START BIT
0524 OBIC 09 24 ORA #$24 ;SET SERVICED BIT
0525 OBIE AO 09 LDY #$09
0526 OB20 85 OD RELI STA KYHOLD
0527 OB22 4C B7 OA JMP RELO
0528 OB25 20 EC OA HTOUT JSR IOFF
0529 OB28 A9 9F LDA #$9F
0530 OB2A 20 9E 09 JSR BITCLR ;ZERO HOLD TIMERS
0531 OB2D 20 EE OF JSR RELRQ ;SET REI,EASE REQUEST BIT
0532 OB30 60 HMIDT5RTS
0533 OB31 A5 OD HTSTR LDA KYHOLD ;TEST HOLD TIMER START BIT
0534 OB33 29 20 AND #$20
0535 OB35 FO F9 BEQ HMIDT5
0536 OB37 A9 67 LDA #$67 ;SET HTSB, HTTB,SB, RC=3
0537 OB39 AO 15 LDY #$15 ;SERVICE 2ND HALF CO SEIZE
0538 OB3B 4C 20 OB JMP RELl
0539 OB3E .FILE LRELDL/I
0540 OB3E KYMUSC e WDI
0541 OB3E A9 FA RELDL LDA #$FA
0542 OB40 85 Cl STA PT22A
0543 OB42 A9 7F LDA #$7F
0544 OB44 25 CO AND PT22B
0545 OB46 85 CO STA PT22B
0546 OB48 26 26 ROL STUS ;WORD2 RELEASE&DIAL ENA
0547 OB4A 18 CLC
0548 OB4B 66 26 ROR STUS
0549 OB4D B5 06 TRSB LDA WDO,X ;TEST RELEASE SERVICED BIT
0550 OB4F 29 20 AND #$20
0551 OB51 FO 18 BEQ TRRB ;BRANCH IT BIT=O
il7872'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 001]
LINE # LOC CODE LINE
0552 OB53 A9 DF LDA #$DF
0553 OB55 20 9E 09 JSR BITCLR
0554 OB58 4C 8D OB JMP TDLEA
0555 OB5B A9 04 TOHB LDA #$04 ;TEST OFF HOOK BIT
0556 OB5D A8 TAY
0557 OB5E 25 26 AND STUS
0558 OB60 FO 06 BEQ SRL ;IF ON HK, SET RELEASE LINE
0559 OB62 20 2D OF JSR CCONT
0560 OB65 4C 6B OB JMP TRRB
0561 OB68 20 13 OF SRL JSR SCONT
0562 OB6B 24 26 TRRB BIT STUS ;TESTS RELEASE REQUEST BIT
0563 OB6D 50 IE BVC TDLEA ;BRANCH ON BIT = O
0564 OB6F A5 26 LDA STUS
0565 OB71 29 8F AND #$BF ;RESET REL REQ.
0566 OB73 09 80 ORA #$80 ;SET RELEASE BIT
0567 OB75 85 26 STA STUS
0568 OB77 B5 06 LDA WDO,X ;SET REL SERV BIT
0569 OB79 09 40 ORA #$40
0570 OB7B 29 7F AND #$7F ;RESET DIAL ENA BIT
0571 OB7D 95 06 STA WDO,X
0572 OB7F AO 04 LDY #$04 ;SET RELEASE LINE
0573 OB81 20 13 OF JSR SCONT
0574 OB84 4C 98 OB OUT JMP EXIT2
0575 OB87 24 07 TLRB BIT WDI
0576 OB89 70 08 BVS SDE8 ;SET DIAL ENABLE BIT
0577 OB8B 50 OB BVC EXIT 2
0578 OB8D A5 26 TDLEA LDA STUS ;TEST DIAL ENA REQ
0579 OB8F 29 08 AND #$08
0580 OB91 FO F4 BEQ TLRB
0581 OB93 ;LDA FUNMUX, TEST DIAL DISABLE FEEDBACK
0582 OB93 :BMI OUT ;BRANCH ID DIAL DISABLE=I
0583 OB93 A9 80 SDEB LDA #$80 ;SET DIAL ENA BIT
0584 OB95 20 A3 09 JSR BITSET
0585 OB98 R5 26 EXIT2 LDA STUS
0586 OB9A 29 04 AND #$4
0587 OB9C DO 14 BNE BGMOFF
0588 OB9E A5 07 LDA KYMUSC
0589 OBAO 4A LSR A
0590 OBAI 90 OF BCC BGMOFF
0591 OBA3 2A ROL A
0592 OBA4 09 04 ORA #$4
0593 OBA6 85 07 STA KYMUSC
0594 OBA8 24 24 BIT KYPAGE
0595 OBAA 30 06 BMI BGMOFF
0596 OBAC A5 CO BGMON LDA PT22B
0597 OBAE 09 20 ORA #$20
0598 OBBO DO 04 BNE FUNCH
0599 OBB2 A5 CO BGMOFFLDA PT22B
0600 OBB4 29 DF AND #$DF
0601 OBB6 85 CO FUNCH STA PT22B
0602 OBB8 A9 F8 LDA #$F8
0603 OBBA 25 Cl AND PT22A
0604 OBBC 85 Cl STA PT22A
0605 OBBE A9 10 LDA #$10
0606 OBCO 4C 6D OA JMP STROBB
33
li787'~'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0012
LINE # LOC CODE LINE
0607 OBC3 .FILE LHNFRE/l
0608 OBC3 ;*************************************
0609 OBC3 ;* HANFRE-HANDS FREE SUBROUTINE *
0610 OBC3 ;* *
0611 OBC3 ;*************************************
0612 OBC3
0613 OBC3
0614 OBC3 20 97 09 HANFRE JSR TCTR3
0615 OBC6 F0 01 BEQ HFRI
0616 OBC8 60 RTS
0617 OBC9 A9 04 HFRI LDA #$04
0618 OBCB 20 A3 09 JSR BITSET
0619 OBCE 29 08 AND #S08 ;TEST SPU ON BIT
0620 OBD0 D0 06 BNE SPOFF
0621 OBD2 A5 31 LDA STUSl
0622 OBD4 09 08 ORA #$08
0623 OBD6 D0 04 BNE EXFRE
0624 OBD8 A5 31 SPOFF LDA STUSl
0625 OBDA 29 F7 AND #$F7
0626 OBDC 09 02 EXFRE ORA #$02
0627 OBDE 85 31 STA STUSl
0628 OBE0 60 RTS
0629 OBEl .FILE LHOTLI/l
0630 OBEl PAGEWD'$17
0631 OBEl A4 26 HTLINE LDY STUS ;TEST RELEASE BIT
0632 OBE3 30 22 BMI HTNOF ;BRANCH TO TURN OFF
0633 OBE5 B5 06 LDA WD0,X ;TEST TRIG BIT
0634 OBE7 29 40 AND #$40
0635 OBE9 D0 35 BNE HTNON
0636 OBEB 20 97 09 JSR TCTR3 ;RESPONSE COUNTER '3?
0637 OBEE C9 02 CMP #$02
0638 OBF0 D0 09 BNE HTLN0
0639 OBF2 A5 OD LDA KYHOLD;FORCE CTR-3
0640 OBF4 09 03 ORA #$3
0641 OBF6 85 OD STA RYHOLD
0642 OBF8 20 FE OB OPENXP JSR CPTOPN;OPEN CROSSPOINT FOR RESPLASH
0643 OBFB 4C 6E 0C HTLN0 JMP LAMP
0644 OBFE 20 EC OA CPTOPN JSR IOFF ;TURN OFF CURRENT GEN
0645 0C01 ; OPEN CROSS POINTS
0646 _ 0C01 20 BC 09 JSR CDL ;SET D EQU 0
0647 0C04 4C 54 OA JMP SXPT ;OPEN XPT
0648 0C07 20 5F 0C HTNOF JSR PAGEON;OPEN CROSSPT SUBROUTINE
0649 OCOA A9 F7 LDA #$F7 ;RESET I HOLD BIT
0650 0C0C 20 9E 09 JSR BITCLR
0651 0C0F 98 TYA
0652 0C10 29 CF AND #$CF ;RESET CONF BIT+HTLINE SEIZE BIT
0653 0C12 85 26 STA STUS
0654 0C14 B5 06 LDA WD0,X ;TEST CTR
0655 0C16 09 40 ORA #$40
0656 0C18 A8 TAY ;HOLD WD0,X IN Y
0657 0C19 29 07 AND #$7
0658 0ClB F0 14 BEQ HTONFI
0659 OClD 98 TYA
0660 OCIE D0 OF BNE HTONF2;BRANCH ALWAYS
0661 0C20 A5 19 HTNON LDA KYHFRE
34
1~787'~f~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0013
LINE # LOC CODE LINE
0662 0C22 30 05 BMI NOHFO ;TEST SPU ON LED
0663 0C24 98 TYA ;GET STATUS
0664 0C25 29 04 AND #$04 ;TEST OFF HOOK BIT
0665 OC27 D0 OB BNE HSTSER
0666 0C29 A9 04 NOHFO LDA #$04
0667 OC2B 15 06 NOHFl ORA WD0,X
0668 OC2D 29 BF AND #$BF ;DEFETE PRESELECT
0669 OC2F 95 06 HTONF2STA WD0,X
0670 0C31 4C 6E 0C HTONFIJMP LAMP
0671 0C34 A9 02 HSTSERLDA #$02
0672 0C36 25 82 AND PT32B ;TEST D2
0673 0C38 D0 EF BNE NOHFO
0674 OC3A 98 TYA ;TEST CONF BIT
0675 OC3B 29 20 AND #$20
0676 OC3D D0 EA BNE NOHFO
0677 OC3F 20 4E OA HCLSXP JSR CLOSEX ;COLSE XPT
0678 0C42 20 53 0C JSR PAGEOF
0679 0C45 A9 20 LDA #$20 ;TVRN ON SEIZE CURRENT
0680 OC47 20 7A OA JSR IIPORT
0681 OC4A 98 TYA ;SET CONF BIT+HTLILE SEIZE BIT0682 OC4B 09 30 ORA #$30
0683 OC4D 85 26 STA STUS
0684 OC4F A9 84 HCONF LDA #$84 ;SET I HOLD BIT TO SET THE FLASHERS
RATE
0685 0C51 D0 D8 BNE NOHFl ;BRANCH ALWAYS
0686 OC53 E0 17 PAGEOF CPX #PAGEWD
0687 0C55 D0 14 BNE PNOTI
0688 0C57 A0 01 LDY #$1
0689 0C59 20 13 OF JSR SCONT
0690 0C5C 4C 6B 0C IMP PNOTl
0691 OC5F 20 FE OB PAGEON JSR CPTOPN
0692 0C62 E0 17 CPX #PAGEWD
0693 0C64 D0 05 BNE PNOTl
0694 0C66 A0 01 LDY #$01
0695 OC68 20 2D OF JSR CCONT
0696 OC6B A4 26 PNOTl LDY STUS
0697 OC6D 60 RTS
0698 OC6E .FILE LGLAMP/l
0699 OC6E B5 06 LAMP LDA WD0,X ;LOOK AT I HOLD BIT
0700 0C70 29 08 AND #$08
0701 0C72 F0 OB BEQ LAMPI
0702 0C74 A5 02 LDA FUNMUX
0703 0C76 29 02 AND #$2 ;TEST QUICK FLASH
0704 0C78 D0 09 BNE LONG
0705 OC7A A9 7F SHORTlLDA #$7F
0706 0C7C 4C 9E 09 JMP BITCLR
0707 OC7F 24 82 LAMPl BIT PT32B
0708 OC81 50 F7 BVC SHORTl
0709 0C83 A9 80 LONG LDA #$80
0710 0C85 4C A3 09 JMP BITSET
07]1 0C88 .FILE LHOKSW/l
0712 0C88 BYPTMR-$0004
0713 OC88 A5 06 HOOKSW LDA WD0
0714 OC8A 29 07 AND #$7
0715 0C8C F0 lE BEQ ONCR0
0716 OC8E C9 03 CMP #S3
1~787'~'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0014
LINE # LOC CODE LINE
0717 OC90 FO 01 BEQ HKI
0718 OC92 60 RTS
0719 OC93 A9 04 HKI LDA #$04
0720 OC95 20 A3 09 JSR BITSET
0721 OC98 A5 19 LDA KYHFRE
0722 OC9A 29 10 AND #$10 ;CHECK ON CRADEL BIT
0723 OC9C DO 01 BNE HK2
0724 OC9E 60 RTS
0725 OC9F A5 19 HK2 LDA KYHFRE
0726 OCAI 29 EF AND #$EF
0727 OCA3 85 19 STA KYHFRE
0728 OCA5 A5 31 LDA STUSI
0729 OCA7 09 10 ORA #$10
0730 OCA9 DO 12 BNE HK4
0731 OCAB 60 RTS
0732 OCAC A5 19 ONCRO LDA KYHFRE
0733 OCAE 29 10 AND #$10
0734 OCBO FO 01 BEQ HK3
0735 OCB2 60 RTS
0736 OCB3 A5 19 HK3 LDA KYHFRE
0736 OCB5 09 10 ORA #$10
0738 OCB7 85 19 STA KYHFRE
0739 OCB9 A5 31 LDA STUSI
0740 OCBB 29 EF AND #$EF
0741 OCBD 09 03 HK4 ORA #$03
0742 OCBF 85 31 STA STUSI
0743 OCCl 60 RTS
0744 OCC2 .FILE LTMFLS/l
0745 OCC2 FLSHTM-$0030
0746 OCC2 FTIME=$0028;DELAY= I SECOND PRECISELY
0747 OCC2 20 97 09 TMFLS JSR TCTR3 ;TEST CTR~3
0748 OCC5 DO 19 BNE TMFLSO
0749 OCC7 A9 04 LDA #4 ;SET SERVICED BIT
0750 OCC9 20 A3 09 JSR BITSET
0751 OCCC A9 28 LDA #FTIME ;SET TIMER
0752 OCCE 85 30 STA FLSHTM
0753 OCDO A5 80 LDA PT32A ;TURN ON FLASH CURRENT
0754 OCD2 29 20 AND #$20 ;ISOLATE SEIZE BIT
0755 OCD4 85 2D STA CURSTA ;PLACE IN CURSTA
0756 OCD6 OA ASL A ;SHIFT S-BIT TO FLASH POSITION
0757 OCD7 OA ASL A
0758 OCD8 20 7A OA JSR IIPORT ;GO TO UPDATE PORT
0759 OCDB 06 30 DECTMR DEC FLSHTM
0760 OCDD FO 06 BEQ TMFOUT
0761 OCDF 60 TMFEXT RTS
0762 OCEO A5 30 TMFLSO LDA FLSHTM
0763 OCE2 DO F7 BNE DECTMR
0764 OCE4 60 RTS
0765 OCE5 4C 78 OA TMFOUT JMP RESPRT ;RETRIEVE PRIEVIOUS CURR
0766 OCE8 .FILE LAUTLK
0767 OCE8 LNKCTR - $2F
0768 OCE8 A4 26 LAUTLK LDY STUS ;TEST REL REQ
0769 OCEA 30 27 BMI AREL ;BRANCH IF SET
0770 OCEC 20 97 09 JSR TCTR3 ;TEST RESPONSE COUNTER
0771 OCEF FO 3B BEQ AOFHK
36
11787'~'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0015
LINE # LOC CODE LINE
0772 OCFI C9 01 CMP #$1 ;CTR=I?
0773 OCF3 FO 01 BEQ ALKO
0774 OCF5 60 RTS
0775 OCF6 98 ALKO TYA ;SET REL REQ BIT
0776 OCF7 09 40 ORA #$40
0777 OCF9 85 26 STA STUS
0778 OCFB B5 06 ALK] LDA WDO,X ;TEST ACTIVE LINE FLAG
0779 OCFD 30 14 BMI AREL
0780 OCFF 20 97 09 NEWMUX JSR TCTR3 ;ISOLATE CTR BITS
0781 OD02 C9 01 CMP #$1
0782 OD04 DO 01 BNE LNMXl
0783 OD06 60 RTS
0784 OD07 E6 05 LNMXI INC LNKMUX
0785 ODO9 A5 05 LDA LNKMUX
0786 ODOB 38 SEC
0787 ODOC E9 04 SBC #$4
0788 ODOE DO 02 BNE AEXIT
0789 ODIO 85 05 STA LNKMUX ;NOTE A=O
0790 OD12 60 AEXIT RTS
0791 OD13 A5 07 AREL LDA WDI ;RESET LINK REQUEST BIT
0792 OD15 29 BF AND #$BF
0793 OD17 85 07 STA WDI
0794 ODI9 20 EC OA JSR IOFF ;TURN OFF CURRENT GEN
0795 ODIC 20 BC 09 JSR CDL ;OPEN CROSSPOINTS
0796 ODIF 20 5F OD JSR ASXPTO ;TICKLE XPT ENABLE
0797 OD22 B5 06 LDA WDO,X
0798 OD24 10 EC BPL AEXIT ;TEST ACTIVE LINE FLAG
0799 OD26 29 07 AND #$7
0800 OD28 95 06 STA WDO,X
0801 OD2A 10 D3 BPL NEWMUX ;BRANCH ALWAYS
0802 OD2C 98 AOFHK TYA
0803 OD2D 29 04 AND #$4 ;TEST OFF HOOK BIT
0804 OD2F FO El BEQ AEXIT
0805 OD31 A5 82 LDA PT32B jTEST D2
0806 OD33 4A LSR A
0807 OD34 BO C5 BCS ALKI ;BRANCH ON D2-1
0808 OD36 E6 2F ACLXPT INC LNKCTR
0809 OD38 A5 2F LDA LNKCTR
0810 OD3A C9 06 CMP #$06
0811 OD3C FO 01 BEQ AUTl
0812 OD3E 60 RTS
0813 OD3F A9 00 AUTI LDA #$00
0814 OD41 85 2F STA LNKCTR
0815 OD43 20 B6 09 JSR SDL ;SET DATA LINE']
0816 OD46 20 5F OD JSR ASXPTO ;TICKEL XPT ENABLE
0817 OD49 A9 10 LDA #$10 ;SET DIAL ENABLE REQ
0818 OD4B 20 FO OF JSR STUSST
0819 OD4E A9 20 LDA #$20 ;TURN ON SEIZE CURRENT
0820 OD50 20 82 OA JSR IPORT
0821 OD53 A9 84 LDA #$84
0822 OD55 20 A3 09 JSR BITSET ;SET SERVICED BIT & ACTIVE LINE
FLAG
0823 OD58 A9 40 LDA #$40 ;SET LINK REQUESI' BIT
G824 OD5A 05 07 ORA WDI
0825 OD5C 85 07 STA WDl
0826 OD5E 60 RTS
11787Z;~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0016
LINE # LOC CODE LINE
0827 OD5F
0828 OD5F ; SUBROUTINE
0829 OD5F
0830 OD5F A5 C1 ASXPTO LDA PT22A ;SAVE PRESENT PORT STATVS
0831 OD61 48 PHA
0832 OD62 A4 05 LDY LNKMVX
0833 OD64 B9 6E OD LDA ATBL,Y ;GET MVX CONTROL PATTERN
0834 OD67 20 58 OA JSR ASXPT
0835 OD6A 68 PLA
0836 OD6B 85 C1 STA PT22A
0837 OD6D 60 RTS
0838 OD6E
0839 OD6E ; ACTIVATION TABLE
0840 OD6E
0841 OD6E 27 ATBL .BYT $27 ;CP24
0842 OD6F 25 .BYT $25 :CP22
0843 OD70 23 .BYT $23 ;CP20
0844 OD71 17 .BYT $17 ;CP16
0845 OD72 .FILE LMIKMT/I
0846 OD72 20 97 09 LMIKMT JSR TCTR3 ;TEST CTR
0847 OD75 DO 11 BNE BYPTST
0848 OD77 A9 04 LDA #$4 ;SET SERVICED BIT
0849 OD79 20 A3 09 JSR BITSET
0850 OD7C 30 10 BMI MLOFF ;BRANCH IF MVTE LED ON
0851 OD7E 09 80 ORA #$80 ;TURN ON MVTE LED
0852 OD80 95 06 STA WDO,X
0853 OD82 26 06 MUTE ROL WDO ;MVTE MIC
0854 OD84 38 SEC
0855 OD85 66 06 LIVEO ROR WDO
0856 OD87 60 RTS
0857 OD88 24 08 BYPTST BIT WD2 ;TEST BYPASS SWITCH
0858 OD8A 30 F6 BMI MVTE ;BRANCH IF BYPASS SWITCH CLOSED
0859 ODBC 10 05 BPL LIVE ;BRANCH IF BYPASS SWITCH OPEN
0860 OD8E A9 7F MLOFF LDA #$7F ;TURN OFF MVTE LED
0861 OD90 20 9E 09 JSR BITCLR
0862 OD93 26 06 LIVE ROL WDO ;LIVE MIC
0863 OD95 18 CLC
0864 OD96 90 ED BCC LIVEO ;BRANCH ALWAYS
0865 OD98 .FILE LGWSRFtl
0866 OD98 PRREL -PREL-I
0867 -OD98 CALL -DELY-I
0868 OD98 CTRLI ~HOOKSW-I
0869 OD98 DENB 'RELDL-I
0870 OD98 MKENB 'DELY-I
0871 OD98 HNDFRl -DELY-l ;SPKR-PHONE CONIROL WORD
0872 OD98 HOLD ~HSRTN-1
0873 OD98 FLASH -TMFLS-l
0874 OD98 HNDFR2 -HANFRE-l ;SPKR-PHONE ON/OFF KEY
0875 OD98 MMVT ~DELY-l
0876 OD98 ANS 'DELY-l
0877 OD98 HLINE ~DELY-l
0878 OD98 DND =DELY-l
0879 OD98 PAGE -HTLINE-l
0880 OD98 CONF ~HTLINE-l
0881 OD98 SEEZO ~COSZ-I
1~787ZZ
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0017
LINE # LOC CODE LINE
0882 OD98 SEEZI =COSZ-]
0883 OD98 SEEZ2 =COSZ-I
0884 OD98 SEEZ3 =COSZ-I
0885 OD98 SEEZ4 =COSZ-I
0886 OD98 SEEZ5 =COSZ-I
0887 OD98 SEEZ6 =COSZ-I
0888 OD98 SEEZ7 =COSZ-I
0889 OD98 SEEZ8 =COSZ-I
0890 OD98 SEEZ9 =COSZ-I
0891 OD98 SEEZIO 5COSZ-
0892 OD98 SEEZII =COSZ-I
0893 OD98 SEEZ12 =COSZ-I
0894 OD98 SEEZ13 =COSZ-I
0895 OD98 SEEZ14 =DELY-I
0896 OD98 SEEZ15 =LMIKMT-I
0896 OD98 SEEZ16 =COSZ-I
0898 OD98 SEEZ17 =COSZ-I
0899 OD98 SEEZ18 =DELY-I
0900 OD98 SEEZ19 =COSZ-I
0901 OD98 SEEZ20 =COSZ-I
0902 OD98 SEEZ21 =COSZ-I
0903 OD98 SEEZ22 =PAGE-I
0904 OD98 SEEZ23 =LAUTLK-I
0905 OD98 CPI =$00
0906 OD98 CP2 5$08
0907 OD98 CP3 =$10
0908 OD98 CP4 =$18
0909 OD98 CP5 =$20
0910 OD98 CP6 =$28
0911 OD98 CP7 =$30
0912 OD98 CP8 =$38
0913 OD98 CP9 =$40
0914 OD98 CPIO =$48
0915 OD98 CPII =$50
0916 OD98 CP12 =$58
0917 OD98 CP13 =$60
0918 OD98 CP14 =$68
0919 OD98 CP15 -$70
0920 OD98 CP16 -$78
0921 OD98 CP17 =$80
0922 OD98 CP18 =$88
0923 OD98 CP19 =$90
0924 OD98 CP20 =$98
0925 OD98 CP21 =$AO
0926 OD98 CP22 =$A8
0927 OD98 CP23 =$BO
0928 OD98 CP24 =$B8
0929 OD98 87 WDFDL .BYT <CTRLI ;WD O
0930 OD99 3D .BYT <DENB ;WD I
0931 OD9A 9C .BYT <MKENB ;WD 2
0932 OD9B 9C .BYT <HNDFRI ;WD 3
0933 OD9C C2 .BYT <SEEZO
0934 OD9D C2 .BYT <SEEZI
0935 OD9E C2 .BYT <SEEZ2
0936 OD9F FC .BYT <HOLD ;WD 7
39
11787;~;~
LARGE SYSTEM 2/28179 BELOW 2K!... PAGE 0018
LINE # LOC CODE LINE
0937 ODAO C2 .BYT <SEEZ3
0938 ODAI C2 .BYT <SEEZ4
0939 ODA2 C2 .BYT <SEEZ5 ;CONVERT WD 10
0940 ODA3 9B .BYT <PRREL ; WD 1 I
0941 ODA4 C2 .BYT <SEEZ6
0942 ODA5 C2 .BYT <SEEZ7
0943 ODA6 C2 .BYT <SEEZ8 ;CONVERT WD 14
0944 ODA7 Cl .BYT <FLASH ; WD 15
0945 ODA8 C2 .BYT <SEEZ9
0946 ODA9 C2 .BYT <SEEZIO
0947 ODAA C2 .BYT cSEEZIl ;CONVERT WD 18
0948 ODAB C2 .BYT <HNDFR2 ; WD 19
0949 ODAC C2 .BYT <SEEZ12
0950 ODAD C2 .BYT <SEEZ13
0951 ODAE 9C .BYT <SEEZ14
0952 ODAF 71 .BYT <SEEZ15 ;PAGE WD 23
0953 ODBO C2 .BYT <SEEZ16
0954 ODBI C2 .BYT <SEE717
0955 ODB2 9C .BYT <SEEZ18
0956 ODB3 C2 .BYT <SEEZl9 ;CNVT / MEET ME WD 27
0957 ODB4 C2 .BYT <SEEZ20
0958 ODB5 C2 .BYT <SEEZ21
0959 ODB6 DF .BYT <SEEZ22
0960 ODB7 E7 .BYT <SEEZ23 ; WORD 3]
0961 ODB8 04 WDFDU .BYT >CTRLI-8; WD O
0962 ODB9 03 .BYT >DENB-8 ; WD I
0963 ODBA 01 .BYT >MKENB-8; WD 2
0964 ODBB 11 .BYT >HNDFRI-8+CP3 ; WD 3
0965 ODBC 21 .BYT >SEEZO-8+CP5
0966 ODBD 31 .BYT >SEEZl-8+CP7
0967 ODBE 01 .BYT >SEEZ2-8
0968 ODBF 2A .BYT >HOLD-8+CP6; WD7
0969 ODCO 39 .BYT >SEEZ3-8+CP8
0970 ODCI 49 .BYT >SEEZ4-8+CP10
0971 ODC2 0: .BYT >SEEZ5-8; CONVERT WD 10
0972 ODC3 42 .BYT >PRREL-8+CP9 ; WD 1 I
0973 ODC4 51 .BYT >SEEZ6-8+CPII
0974 ODC5 61 .BYT >SEEZ7-8+CP13
0975 ODC6 01 .BYT >SEEZ8-8 ; CONVERT WD 14
0976 ODC7 5C .BYT >FLASH-8+CP12 ; WD 15
0977 ODC8 69 .BYT >SEEZ9-8+CP14
0978 ODC9 81 .BYT >SEEZ10-8+CP17
0979 ODCA 01 .BYT >SEEZ11-8 ; CONVERT WD 18
0980 ODCB 73 .BYT >HNDFR2-8+CP15 ; WD 19
0981 ODCC 89 .BYT >SEEZ12-8+CP18
0982 ODCD 69 .BYT >SEEZ13-8+CP14
0983 ODCE 79 .BYT >SEEZ14-8+CP16
0984 ODCF 95 .BYT >SEEZ15-8+CP19 ; PAGE WD 23
0985 ODDO 01 .BYT >SEEZ16-8+CPI
0986 ODDI 89 .BYT >SEEZ17-8+CP18
0987 ODD2 Bl .BYT >SEEZ18-8+CP23
0988 ODD3 09 .BYT >SEEZ19-8+CP2 ; CNVT / MEET ME WD 27
0989 ODD4 19 .BYT >SEEZ20-8+CP4
0990 ODD5 Al .BYT >SEEZ21-81CP21
0991 ODD6 2B .BYT >SEEZ22-8+CP6
117872;~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0019
LINE # LOC CODE LINE
0992 ODD7 04 .BYT >SEEZ23-8 ; WORD 31
0993 ODD8 BD B8 OD WSRF LDA WDFDU,X ;FETCH UPPER ADD. BYTE
0994 ODDB 85 2E STA MUX ;SAVE CP. CODE
0995 ODDD 29 07 AND #$7 ;MASK OUT ADDRESS DATA
0996 ODDF 09 08 ORA #$8 ;SET ADDRESS BIT All
0997 ODEl 48 PHA ;SET UPPER VECTOR
0998 ODE2 BD 98 OD LDA WDFDL,X ;FETCH LOWER ADDRESS BYTE0999 ODE5 48 PHA ;SET LOWER VECTOR
1000 ODE6 60 RTS
1001 ODE7 .FILE LBPORT/l
1002 ODE7 BPTRAM - $01
1003 ODE7 TEMP ' $00
1004 ODE7 WDO -$0006
1005 ODE7 A5 82 BPORT LDA PT32B
1006 ODE9 29 30 AND #$30
1007 ODEB FO 37 BEQ IDI ;TEST HL SEIZE BIT
1008 ODED A5 82 LDA PT32B
1009 ODEF 29 IC AND #$1C ;TEST LINK BITS (STEAL,ST,RT)
1010 ODFl C9 18 CMP #$18
1011 ODF3 FO IE BEQ IDLE
]012 ODF5 48 PHA
1013 ODF6 E6 2F INC LNKCTR
1014 ODF8 A5 2F LDA LNKCTR
1015 ODFA C9 10 CMP #$10
1016 ODFC FO 04 BEQ BPI
1017 ODFE 68 PLA
1018 ODFF 4C 65 OE JMP BPORTl
1019 OE02 A9 00 BPI LDA #$00
1020 OE04 85 2F STA LNKCTR
1021 OE06 68 PLA
1022 OE07 C9 04 FIND CMP #$04 ;IS IT STEAL?
1023 OE09 FO IC BEQ STEAL ;YES, DO STEAL ROUTINE
1024 OEOB C9 14 CMP #$14 ;IS IT RING?
1025 OEOD FO 33 BEQ RT ;YES, DO RT ROUTINE
1026 OEOF C9 IC CMP #$1C ;IS IT H.F. CALL?
1027 OEll FO 17 BEQ ST ; DO SPLASH TONE ROUTINE
1028 OE13 A5 01 IDLE LDA BPTRAM ;GET CONTROL WORD (WDO)
1029 OE15 29 08 AND #$08 ;TEST HF SERVICE BIT
1030 OE17 FO OB BEQ IDI ;IF NOT SET CONT.
1031 OE19 A5 01 LDA BPTRAM
1032 OEIB 29 C7 AND #$C7 ;CLEAR B LINK CONTROL BITS
1033 OEID 85 01 STA BPTRAM ;RESET SERVICE BIT
1034 OElF 26 19 ROL WD19
1035 OE21 18 CLC
1036 OE22 66 19 ROR WD19 ;HF LED OFF
1037 OE24 20 39 OF IDl JSR RINGRS
1038 OE27 4C 65 OE STEAL JMP BPORTI
1039 OE 2A A5 01 ST LDA BPTRAM ;IF NONE OF THE ABOVE IT IS ST
1040 OE2C 29 08 AND #$08 ;SET ST SERVICE BIT
1041 OE2E DO F4 BNE IDl ;SERVICE BIT SET RETURN
1042 OE30 A5 01 LDA BPTRAM
1043 OE32 09 08 ORA #$08
1044 OE34 85 01 STA BPTRAM ;SET SERVICE BIT
1045 OE36 A9 04 LDA #$4
1046 OE38 20 A7 09 JSR STB32A
11787Z'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0020
LINE # LOC CODE LINE
1047 OE3B 26 19 ROL WD19
1048 OE3D 38 SEC
1049 OE3E 66 19 ROR WD 19 ;TURN ON HF LED
1050 OE40 30 23 BMI BPORTI ;BRANCH ALWAYS
1051 OE42 A5 01 RT LDA BPTRAM
1052 OE44 29 10 AND #$10
1053 OE46 DO OB BNE RTl ;BRANCH IF SERVICE BIT SET
1054 OE48 20 33 OF JSR RINGST
1055 OE4B A5 01 LDA BPTRAM
1056 OE4D 09 10 ORA #$10
1057 OE4F 85 01 STA BPTRAM ;SET RT SERVICE BIT
1058 OE51 DO 12 BNE BPORTl ;BRANCH ALWAYS
1059 OE53 A5 19 RTl LDA WDl9
1060 OE55 29 10 AND #$10
1061 OE57 DO OC BNE BPORTI ;OFHK THAN CONT.
1062 OE59 20 39 OF JSR RINGRS ;RESET RT ENA
1063 OE5C A5 CO LDA PT22B
1064 OE5E 09 04 ORA #$04
1065 OE60 85 CO STA PT22B
1066 OE62 20 Cl OF JSR SPPl
1067 OE65 ;***********************
1068 OE65 AO 07 BPORTl LDY #$07 ;SET FUNMUX CYCLE CTR
1069 OE67 A9 FF LDA #$FF
1070 OE69 85 Cl STA PT22A
1071 OE6B A5 CO LDA PT22B ;TOGGLE FUNMUX SELECT
1072 OE6D 29 7F AND #$7F
1073 OE6F 48 PHA
1074 OE70 85 CO STA PT22B
1075 OE72 A5 82 BPT3 LDA PT32B ;READ ONE FUNMUX BIT
1076 OE74 OA ASL A
1077 OE75 26 02 ROL FUNMUX ;SHIFT RESULTS INTO FUNMUX
1078 OE77 88 DEY
1079 OE78 30 04 BMI BPT4
1080 OE7A C6 C] DEC PT22A
1081 OE7C DO F4 BNE BPT3 ;BRANCH ALWAYS
1082 OE7E 68 BPT4 PLA
1083 OE7F 09 80 ORA #$80 ;RESTORE PT22B
1084 OE81 85 CO STA PT22B
1085 OE83 A5 82 LDA PT32B ;READ CONF KEY SELECT
1086 OE85 A8 TAY ;SAVE HL SEIZE BIT
1087 OE86 29 04 AND #$4
1088 OE88 08 PHP
1089 OE89 A5 02 LDA FUNMUX
1090 OE8B 48 PHA
1091 OE8C 29 10 AND #$10 ;ISOLATE HF ENABLE
1092 OE8E 85 03 STA HFENAB
1093 OE90 68 PLA
1094 OE91 29 EF AND #$EF
1095 CE93 28 PLP
1096 OE94 FO 02 BEQ BPT5 ;MOVE CONF STRAP TO FUNMUX
1097 OE96 09 10 ORA #$10
1098 OE98 85 02 BPT5 STA FUNMUX
1099 OE9A 98 TYA ;GET PT32B
1100 OE9B 29 20 AND ~$20 ;TEST HL SEIZE BIT
1101 OE9D DO 18 BNE NTSEZD
42
11~7872'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0021
LINE # LOC CODE LINE
1102 OE9F A5 01 SEZD LDA BPTRAM
1103 OEAI A8 TAY
1104 OEA2 20 99 09 JSR CTR3
1105 OEA5 FO 48 BEQ BPTI
1106 OEA7 C9 07 CMP #$07
1107 OEA9 FO 30 BEQ BPT2
1108 OEAB E6 01 INC BPTRAM
1109 OEAD A5 19 TSPUEN LDA KYHFRE ;TEST SPU LAMP
1110 OEAF 30 33 BMI SPUOFF
1111 OEBI 20 04 OF JSR SCONTI ;CONTI-I
1112 OEB4 4C ]I OF JMP SCONT2 ;CONT2=1
1113 OEB7 A5 01 NTSEZD LDA BPTRAM
1114 OEB9 C9 07 CMP #$07
1115 OEBB DO OF BNE NTSZDO
1116 OEBD 20 04 OF JSR SCONTI ;CONT]-I
1117 OECO 20 2B OF JSR CCONT2 ;CONT2=0
1118 OEC3 24 19 BIT KYHFRE
1119 OEC5 70 05 BVS NTSZDO
1120 OEC7 26 19 ROL KYHFRE ;HANDS FREE LED OFF
1121 OEC9 18 CLC
1122 OECA 66 19 ROR KYHFRE
1123 OECC A5 01 NTSZDO LDA BPTRAM
1124 OECE 29 38 AND #$38 ;CLEAR BPORT RAM
1125 OEDO 85 01 STA BPTRAM
1126 OED2 A5 CO LDA PT22B ;CLEAR LINK B ENAB
1127 OED4 29 FD AND #$FD
1128 OED6 85 CO STA PT22B
1129 OED8 4C AD OE JMP TSPUEN
1130 OEDB 20 OA OF BPT2 JSR CCONTI ;CONTl-O
1131 OEDE 20 2B OF JSR CCONT2 ;CONT2'0
1132 OEEl 4C AD OE JMP TSPUEN
1133 OEE4 20 2B OF SPUOFF JSR CCONT2 ;CONT2-0
1134 OEE7 A5 19 LDA KYHFRE
1135 OEE9 29 10 AND #$10 ;TEST OFF HOOK BIT
1136 OEEB FO ID BEQ CCONTI ;FOR FAST FLASH USE OFFHK
1137 OEED DO 15 BNE SCONTI ;TURN LED OFF IF HANSET AND SP
ON HK
1138 OEEF 98 BPTI TYA
1139 OEFO 09 04 ORA #$4 ;SET SERVICED BIT
1140 OEF2 85 01 STA BPTRAM
1141 OEF4 A9 02 LDA #$2 ;SET HL ENAB.
1142 OEF6 20 A7 09 JSR STB32A
1143 OEF9 20 DF OF JSR LTON ;TURN ON HANDS FREE LED
1144 OEFC 4C AD OE JMP TSPUEN
1145 OEFF A5 02 OFFHK LDA FUNMUX ;CONTI-O
1146 OFOI 4A LSR A ;TEST SL~W FLASH BIT
1147 OF02 DO 06 BNE CCONTI ;LED ON
1148 OF04
1149 OF04
1150 OF04 ; BPORT SUBROUTINES
]151 OF04
1152 OF04 A5 CO SCONTI LDA PT22B ;SET DO
1153 OF06 09 01 ORA #$1
1154 OF08 DO 04 BNE PRT22B
1155 OFOA A5 CO CCONTI LDA PT22B ;CLEAR DO
1156 OFOC 29 FE AND #$FE
~.i787Z'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0022
LINE # LOC CODE LINE
1157 OFOE 85 CO PRT22B STA PT22B
1158 OFIO 60 WAIT RTS
1159 OFll AO 02 SCONT2 LDY #$2 ;POINT TO CONT2
1160 OF13 20 B6 09 SCONT JSR SDL ;SET D-l
1161 OF16 84 00 CONT STY TEMP ;ENTRY POINT FOR FUNMUX WRITE
1162 OF18 A5 Cl LDA PT22A ;ADDRESS FUNMUX
1163 OFIA 29 F8 AND #$F8
1164 OF1C 05 00 ORA TEMP
1165 OFlE B5 Cl STA PT22A
1166 OF20 A5 CO LDA PT22B ;STROBE WES4 NOT
1167 OF22 49 10 EOR #$10
1168 OF24 85 CO STA PT22B
1169 OF26 49 10 EOR #$10
1170 OF28 85 CO STA PT22B
1171 OF2A 60 RTS
1172 OF2B AO 02 CCONT2 LDY #$2 ;POINT TO CONT2
1173 OF2D 20 BC 09 CCONT JSR CDL ;CLEAR D
1174 OF30 4C 16 OF JMP CONT
1175 OF33 A5 80 RINGST LDA PT32A
1176 OF35 09 04 ORA #$04
1177 OF37 DO 04 BNE RING ;BRANCH ALWAYS
1178 OF39 A5 80 RINGRS LDA PT32A
1179 OF3B 29 FB AND #$FB
1180 OF3D 85 80 RING STA PT32A
1181 OF3F 60 RTS
1182 OF40 .FILE SUPR/l
1183 OF40 ; SUPR- SWITCH SUB FOR HF,HS & BPORT
1184 OF40 ;~-~5~ r=~=~==~
1185 OF40
1186 OF40
1187 OF40 EA SHSH NOP
1188 OF41 A5 31 LDA STUSI
1189 OF43 29 03 AND #$03
1190 OF45 DO 01 BNE SUPRl
1191 OF47 60 RTS
1192 OF48 A5 31 SUPRl LDA STUSI
1193 OF4A C9 02 CMP #$02
1194 OF4C FO 60 BEQ OB02
1195 OF4E C9 07 CMP #$07
1196 OF50 FO 62 BEQ 0703
1197 -OF52 C9 03 CMP #$03
1198 OF54 FO 5E BEQ 0703
1199 OF56 C9 OF CMP #$0F
1200 OF58 FO 4E BEQ OF
1201 OF5A C9 13 CMP #$13
1202 OF5C FO 46 BEQ 013
1203 OF5E C9 IF CMP #$1F
1204 OF60 FO 3F BEQ OIF17
1205 OF62 C9 17 CMP #$17
1206 OF64 FO 3B BEQ OlF17
1207 OF66 C9 lB CMP #$1B
1208 OF68 FO 34 BEQ OlB
1209 OF6A C9 OA CMP #$0A
1210 OF6C FO 27 BEQ OA
1211 OF6E C9 12 CMP #$12
~1 ~8 7Z~:
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0023
LINE # LOC CODE LINE
1212 OF70 FO IC BEQ 012
1213 OF72 C9 11 CMP #$11
1214 OF74 FO IB BEQ 01101
1215 OF76 C9 01 CMP #$01
1216 OF78 FO 17 BEQ 01101
1217 OF7A C9 IA CMP #$1A
1218 OF7C FO 09 BEQ OIA
1219 OF7E C9 05 CMP #$05
1220 OF80 FO 08 BEQ 00515
1221 OF82 C9 15 CMP #$15
1222 OF84 FO 04 BEQ 00515
1223 OF86 60 RTS
1224 OF87 20 BB OF OIA JSR SPUON
1225 OF8A 20 DF OF 00515 JSR LTON
1226 OF8D 60 RTS
1227 OF8E 20 C7 OF 012 JSR POFF
1228 OF91 20 D9 OF 01101 JSR LTOFF
1229 OF94 60 RTS
1230 OF95 20 BB OF OA JSR SPUON
1231 OF98 20 DF OF JSR LTON
1232 OF9B 4C A4 OF JMP 013
1233 OF9E 20 D9 OF OIB JSR LTOFF
1234 OFAI 20 C7 OF OIF17 JSR POFF
1235 OFA4 20 E5 OF 013 JSR OFK
1236 OFA7 60 RTS
1237 OFA8 20 C7 OF OF JSR POFF
1238 OFAB 4C B7 OF JMP ENTO
1239 OFAE 20 C7 OF OB02 JSR POFF
1240 OFBI 20 D9 OF JSR LTOFF
1241 OFB4 20 E9 OF 0703 JSR ONHK
1242 OFB7 20 EE OF ENTO JSR RELRQ
1243 OFBA 60 RTS
1244 OFBB ;************************************
1245 OFBB A5 19 SPUON LDA WDI9
1246 OFBD 09 08 ORA #$08
1247 OFBF 85 19 STA WDI9
1248 OFCI 26 09 SPPI ROL WD3
1249 OFC3 38 SEC
1250 OFC4 66 09 ROR WD3
1251 OFC6 60 RTS
1252 OFC7 A5 19 POFF LDA WD19
1253 OFC9 29 F7 AND #$F7
1254 OFCB 85 19 STA WDl9
1255 OFCD A5 31 LDA STUSI
1256 OFCF 29 F7 AND #$F7
1257 OFDI 85 31 STA STUSl
1258 OFD3 26 09 ROL WD3
1259 OFD5 18 CLC
1260 OFD6 66 09 ROR WD3
1261 OFD8 60 RTS
1262 OFD9 26 19 LTOFF ROL WDI9
1263 OFDB 18 CLC
1264 OFDC 66 19 ROR WD19
1265 OFDE 60 RTS
1266 OFDF 26 19 LTON ROL WD19
~7872'~
LARGE SYSTEM 2/28/79 BELOW 2K!... PAGE 0024
LINE # LOC CODE LINE
1267 OFEI 38 SEC
1268 OFE2 66 19 ROR WD19
1269 OFE4 60 RTS
1270 OFE5 A9 04 OFK LDA #$04
1271 OFE7 DO 07 BNE STUSST
1272 OFE9 A9 FB ONHK LDA #$FB
1273 OFEB 4C F5 OF JMP STUSRS
1274 OFEE A9 40 RELRQ LDA #$40
1275 OFFO 05 26 STUSST ORA STUS
1276 OFF2 85 26 STA STUS
1277 OFF4 60 RTS
1278 OFF5 25 26 STUSRS AND STUS
1279 OFF7 85 26 STA STUS
]280 OFF9 60 RTS
1281 OFFA .END LMAINL/I
ERRORS - 0000 <0000>
46
1~7~ Z
SYMBOL TABLE
SYMBOL VALUE
ACLXPT OD36 ADDI 0938 ADD2 0937 ADD3 0936
ADSTB 08FE AEXIT OD12 ALKO OCF6 ALK] OCFB
ANS O99C AOFHK OD2C ARC OOCB ARCOS OAOO
AREL OD]3 ASXPT OA58 ASXPTO OD5F ATBL OD6E
ATBL] 0993 AUTI OD3F BGMOFF OBB2 BGMON OBAC
BITCLR O99E BITOP O9AO BITSET O9A3 BP] OE02
BPORT ODE7 BPORT] OE65 BPT] OEEF BPT2 OEDB
BPT3 OE72 BPT4 OE7E BPT5 OE98 BPTRAM 0001
BYPTMR 0004 BYPTST OD88 CALL 099C CCONT OF2D
CCONTI OFOA CCONT2 OF2B CDL O9BC CLINTI OOCO
CLOSEX OA4E CLSXPT OA20 CONF OBEO CONT OF]6
COSZ O9C3 COSZO O9D8 COSZ] OA3C CP] 0000
CP10 0048 CPII 0050 CP12 0058 CP13 0060
CP14 0068 CP15 0070 CP16 0078 CP17 0080
CP18 0088 CPI9 0090 CP2 0008 CP20 0098
CP2] OOAO CP22 OOA8 CP23 OOBO CP24 OOB8
CP3 00]0 CP4 0018 CP5 0020 CP6 0028
CP7 0030 CP8 0038 CP9 0040 CPTOPN OBFE
CTR3 0999 CTRL] OC87 CTUI 094D CTU2 0962
CTU4 0975 CURSTA 002D DECTMR OCDB DELAY 002F
DELY O99D DENB OB3D DIALST 0899 DINT 0896
DIPT2A OOC3 DIPT2B OOC2 DIPT3A 008] DIPT3B 0083
DLO O9CO DLYO 08DA DLY2 08D8 DLYQ 08D4
DND 099C DSSHLD 080D ENDTBL 09]8 ENTO OFB7
EXFRE OBDC EXIT2 OB98 EXIT5 O9EA FIND OE07
FLASH OCC] FLSHTM 0030 FNMX] 0029 FTIME 0028
FUNCH OBB6 FUNMUX 0002 HANFRE OBC3 HCLSXP OC3F
HCONF OC4F HFENAB 0003 HFR] OBC9 HK] OC93
HK2 OC9F HK3 OCB3 HK4 OCBD HLINE O99C
HMIDT5 OB30 HNDFR] O99C HNDFR2 OBC2 HOLD OAFC
HOOKSW OC88 HSRTN OAFD HSTSER OC34 HTLINE OBEI
HTLNO OBFB HTNOF OC07 HTNON OC20 HTONFI OC31
HTONF2 OC2F HTOUT OB25 HTSTR OB3] IDI OE24
IDLE OE13 IHP O9E7 IHPO O9ED IHPI O9EO
IIPORT OA7A INCT 0985 INDXI 002B INDX2 002C
INDX4 0027 INDX5 0028 INIT 087E INITDL 0879
INITRP 088E INTBT OOCE INTEA 0887 INTRTN 08A2
IOFF OAEC IPORT OA82 KYANS 00]9 KYBPSS 0008
KYCONT 0021 KYFLS8 0015 KYHFRE 0019 KYHKSW 0006
KYHOLD OOOD KYMUSC 0007 KYPAGE 0024 KYPREL 0011
KYSPU 0009 LAMP OC6E LAMPI OC7F LAUTLK OCE8
LDLTCH OOC5 LIVE OD93 LIVEO OD85 LLTCH OOC6
LMIKMT OD72 LNKCTR 002F LNKMUX 0005 LNMXI OD07
LONG OC83 LOPI 094A LOWCT OOC4 LSMX 0927
LTOFF OFD9 LTON OFDF MKENB O99C MLOFF OD8E
MMUT O99C MRGl 0947 MSCTR 0032 MUTE OD82
MUX 002E NEWMVX OCFF NOHFI OC2B NOHFO OC29
NTSEZD OEB7 NTSZDO OECC 00515 OF8A 01]0] OF9]
012 OF8E 0]3 OFA4 OIA OF87 OIB OF9E
OIF17 OFA] 0703 OFB4 OA OF95 OB02 OFAE
OF OFA8 OFFHK OEFF OFK OFE5 ONCRO OCAC
ONHK OFE9 OPENXP OBF8 OUT OB84 OUTHI 086C
OUTHIO 0870 OUTLO 0873 PAGE OBEO PAGEOF OC53
PAGEON OC5F PAGEWD 0017 PMIDT5 OAD5 PNOTI OC6B
POFF OFC7 PRC OOCC PREL OA9C PRREL OA9B
PRT22B OFOE PSIHLD OABC PSTHO OACO PSTHI OAD3
47
SYMBOL TABLE ~7
SYMBOL VALUE
PSTH2 OADO PSTH3 OAB3 PT22A OOC] PT22B OOCO
PT32A 0080 PT32B 0082 PTOUT OAD6 PTSTR OAF1
PWON 0800 RELO OAB7 REL1 OB20 RELDL OB3E
RELRQ OFEE RESET 0801 RESPRT OA78 RESPST 08A6
RING OF3D RINGRS OF39 RINGST OF33 ROLOVR OA6B
RSTLP 0812 RT OE42 RT1 OE53 SCBT OA3A
SCONT OF13 SCONT1 OF04 SCONT2 OF11 SDEB OB93
SDL O9B6 SEEZO O9C2 SEEZ1 O9C2 SEEZ10 O9C2
SEEZ11 O9C2 SEEZ12 O9C2 SEEZ]3 O9C2 SEEZ14 O99C
SEEZ15 OD71 SEEZ16 O9C2 SEEZ17 O9C2 SEEZ18 O99C
SEEZ19 O9C2 SEEZ2 O9C2 SEEZ20 O9C2 SEEZ21 O9C2
SEEZ22 OBDF SEEZ23 OCE7 SEEZ3 O9C2 SEEZ4 O9C2
SEEZ5 O9C2 SEEZ6 O9C2 SEEZ7 O9C2 SEEZ8 O9C2
SEEZ9 O9C2 SEZD OE9F SHORT 0944 SHORT1 OC7A
SHSH OF40 SPOFF OBD8 SPP1 OFC1 SPUOFF OEE4
SPUON OFBB SRL OB68 SRRBIT O9D6 ST OE2A
START 0919 STB32A O9A7 STEAL OE27 STLLTH 08CO
STLTCH 08BE STROBA OA60 STROBB OA6D STSER OA12
STUS 0026 STUS1 0031 STUSRS OFF5 STUSST OFFO
SUPR1 OF48 SUPTBL 0901 SXPT OA54 SYBY 08C3
SYBYl 08CE SYCT1 083C SYLP1 0886 SYLP2 08BA
SYNC 0825 SYNClA 0852 SYNC2 0858 SYNC5 0866
SYNCA 0982 TlCT OOC1 TlP5T 08AE T1T 08FO
T2P5T 08F7 TCTR3 0997 TDLEA OB8D TEMP 0000
TIFL OOCD TLRB OB87 TMFEXT OCDF TMFLS OCC2
TMFLSO OCEO TMFOUT OCE5 TMP1 0029 TNOF O9F6
TNON OAOD TOHB OB5B TRRB OB6B TRSB OB4D
TSPUEN OEAD TTIME 08DE TTMR 002A ULTCH OOC7
UPCT OOC5 WAIT OF10 WDO 0006 WD1 0007
WD10 0010 WD11 0011 WD12 0012 WD13 0013
WD14 0014 WD15 0015 WD16 0016 WD17 0017
WD18 0018 WD19 0019 WD2 0008 WD20 001A
WD21 001B WD22 001C WD23 001D WD24 001E
WD25 001F WD26 0020 WD27 0021 WD28 0022
WD29 0023 WD3 0009 WD30 0024 WD31 0025
WD4 OOOA WD5 OOOB WD6 OGOC WD7 OOOD
WD8 OOOE WD9 OOOF WDFDL OD98 WDFDU ODB8
WSRF ODD8 XREF OA87 ZROLP 0804
END OF ASSEMBLY
48
11787'~Z
Referring specifically to the circuit shown in Figure
5, each line card 300 includes a single passive port which is
connected to one active port of each of a variable number of
station cards 200 in the system of Figure 1, and also to an
active port in each of the link cards in the system of Figure
2. The passive port receives DC signal currents from the conn-
ected active ports through the shunt resistor 304 and through
the DC signal current-receiving winding of transformer
302, and current sensing circuits 306 generate either a SEI%E,
ELASH, or HOLD/PRRL (privacy release) signals depending upon
whether the DC signal current is 1.6ma, 6.4ma, or 7-14ma. The
SEIZE signal causes the seize relay control circuit 310 to
energize the winding of seize relay 312, causing the ganged
armatures to disconnect from load resistor 314 and establish
connections to the tip T and ring R of the CO line. The SEIZE
signal ~imultaneously triggers timer circuit 319 which activ-
ates a clamping circuit 321 for about 1 second in order to limit
the noise and ringing signal coming in from the CO line. With
the line seized, dialing may be accomplished at the station set
by either dual-tone, multi-frequency (DTMF) signal generators
or by an outpulse generator. DTMF dial signals are transmitted
through transformer 302, music-on-hold interface circuit 322,
bi-directional amplifier 320, transformer 318, and seize relay
312 to the CO line. Outpulse dialing is accomplished by pulse-
modulating the SEIZE signal so as to cause the seize relay 312
to modulate the loop current as a function of the pulses gener-
ated at the station set.
The SEIZE signal is also fed to the voltage sender 324,
which responds by generating a DC signal voltage (-2v.) indi-
cating seizure of the line card passive port. If the seized COline is put on hold by transmission of a 14 ma DC current pulse
49
li787ZZ
from the seizing port, a current sensing circuit 306 generates
a HOLD signal pulse which causes hold condition sensing circuit
308 to generate a constant output which activates the NOH
interface circuit 322 to pass the MOH SOURCE signal received
via the tone card 500 to the held CO line. Because the analog
crosspoint in the previously seizing active port is now open,
no signal current will flow to current sensing circuits 306,
and the MOH SOURCE will not be heard at the associated station
set. The output of the hold condition sensing circuit 308 is
also fed to an input of AND gate 332, which receives a second
input from inverter 328 in response to the termination of the
SEIZE signal, and a third input F-FLASH which is received from
the tone card 500. The output of AND gate 332 consequently
fluctuates in synchronism with the F-FLASH SIGNAL, as does the
output of voltage sender 324, thereby signalling the digital
crosspoints of every connected active port that the CO line
is on hold and may be seized by any connected active port. A
PRRL signal pulse from one of the current sensing circuits 306
in response to a-7-14ma DC signal current pulse from the seizing
active port will cause hold condition sensing circuit 308 to
generate a constant output, so that the MOH interface circuit
322 will be activated and one input will be provided to AND
circuit 332. The SEIZE signal is simultaneously terminated by
de-activation of the DC current signal generator in the seizing
active port, causing inverter 328 to provide another input to
AND circuit 332. Thus, voltage sender 324 ceases to generate
a seized voltage signal (-2v.) and begins to generate an output
which fluctuates between Ov. and -2v. at the F-FLASH rate.
Therefore, other station sets ~90 in the system are informed
that they may also make connection to the CO line.
3.1787Z'~
~ hen a FLASH signal is generated by one of current
sensing circuits 306 in response to a flash DC curr~nt signal
(6.4 ma), the flash switch control circuit 326 responds by
de-activating seize relay control circuit 310 for about 1
secoDd, thereby breaking the connection of seize relay 312 to
the CO line for that period of time. The SEIZE signal is not
interrupted, however. Thus, loop current is broken to dis-
connect the outside party' 6 circuit from the C~ line while
retaining the line for another call. If the EKTS is employed
behind a PBX which requires it, this line card circuit is
modified by breaking the controlling connection from flash
switch control circuit 326 to the seize relay control circuit
310, and by adding a relay 316 which has its armature con-
nected directly to the upper armature of seize relay 312. In
this revi~ed circuit, the generation of the FLASH signal will
not affect the seize relay control circuit 310, lea~ing the
seize relay 312 energized to connect transformer 318 to the
PBX line, but the flash switch control circuit 326 will cause
relay 316 to connect the conductor T to circuit ground during
FL~SH. As in the first embodiment of thi~ circuit, the SEIZE
signal is not terminated. Thus, loop current is broken to
disconnect the other party's circuit from the PBX line while
retaining the line in order to place another call.
In the case of an incoming call, the ringing signal
from the central office will cause ring detection circuit 328
to activate incoming ring indicator circuit 330, which then
generates an INCOMING CALL ENABLE signal which is fed to tone
card 500, and a logic 1 input signal to AND gate 330. Since
there is no SEIZE signal, the output of inverter 328 is also
logic 1. Thus, the S-FLASH signal will pass through AND gate
330 to modulate the output of voltage sender 324 to provide an
51
11787'~'~
indication of the inco~ing call to the digital crosspoints of
the connected active ports, any one of which may seize the
passive port of the line card circuit and thereby seize the
associated CO line.
Referring specifically to the circuit shown in Figure
6, tone generator card 500 comprises a 64 hz oscillator circuit
502 which provides a square ~ave to the countdown combiner and
driver circuits 504, and these in turn generate a Q-FLASH
(I-hold) signal, an F-FLASH (hold) signal, and an S-FLASH
(incoming call) signal. The Q-FLASH and S-FLASH signals are
fed to the function multiplexer 230 of station card circuit
200 (Figure 3) to be sampled, the samples being serially trans-
mitted to microcomputer 216 for possible inclusion in the data
transmitted to the associated station set 100. The S-FLASH
and F-FLASH signals are fed to line card 300. The countdown
combiner and driver circuits 504 also provide driver signals
to the driver circuits 506, 508, 510 and 512, which also receive
the output of combiner circuit 514, which mixes the outputs of
the 400 hz oscillator circuit 516 and the 470 hz oscillator
circuit 518. These oscillator outputs are also fed to driver
circuits 520 and 522, respectively, which generate DIAL TONE
and SPLASH TONE, respectively. DIAL TONE is fed only to the
register card circuit(s) 800, and SPLASH TONE is fed only to
the station cards 200.
Driver circuit 506 produces CO AUDIBLE tone at the rate
of 1 second on, 1 second off, 1 second on, 3 seconds off, and is
fed to the station cards 200 and page card 400. Driver circuit
508 produces ICM RING TONE at two isolated outputs at the rate
of 1 second on, 3 seconds offt and is fed only to the station
cards 200. Driver circuit 510 produces BUSY TONE at the rate
117872'~
of 0.5 second on, 0.5 second off, and is fed only to the link
card circuit(s) 700. Driver circuit 512 produces REORDER TONE
at the rate of 0.125 second on, 0.125 second off. The outputs
of driver circuits508, 510, 512 and 520 are all employed in
internal link functions, and may be eliminated in a system which
has no link circuits 700.
The split ringing and gating circuit 524 receives the
INCOMING CALL ENABLE signals which the line cards 300 generate
when an incoming call is detected, and in response generates
several CO AUDIBLE ENABLE signals, any one or more of which can
be transmitted through backplane wiring to any station card 200
or group of station cards 200. For example, if an INCOMING
CALL ENABLE signal is received from line card 1, 2 or 3, a CO
AUDIBLE ENABLE signal is sent from output COEGPA via the back-
plane to a predetermined group of station cards 200. The
following outputs COEGPB, C, D, E, F and G are similarly assoc-
iated with line cards 4-6, 7-9, 10-12, 13-15, 16-18 and 19-21,
respectively. Output COE 1-14 is associated with line cards
1-14, and a CO AUDIBLE ENABLE signal will be provided via the
backplane to all of the station cards 200 connected to this
output. Output COE 15-18/19 is similarly associated with line
cards 15-18/19, and COE 15-19/21 is similarly associated with
line cards 15-19/21. This arrangement provides great flexi-
bility in the distribution of the CO AUDIBLE tone, e.g., en-
abling direct signalling to predetermined small groups of
station sets behind PB~ that there is an incoming call from
one of a small group of CO lines, and facilitating the pre-
vention of such direct signalling on those incoming calls that
are received at an attendant's station for forwarding to the
called party.
1~7872Z
A station set 100 designated by backplane wiring
controls the night ring control circuit 526. As in all station
sets, the BGM ENABLE signal is generated in response to turn-
on of the BGM control switch. Due to the connection of the
BGM ENABLE signal output from the station card 200 associated
with the designated station set 100 to the night ring control
circuit 526, turn-on of the BGM control switch at the station
set enables generation of the NR ENABLE signal upon receipt of
a logic level signal from the split ringing and gating circuit
524 in response to any INCOMING CALL ENABLE signal. The NR
ENABLE signal is fed to page card 400 to broadcast CO AUDIBLE
TONE as an all-page transmission. The optional MOH interface
circuit 528 distributes the MOH SOURCE signal to all line
cards selected to receive it through the backplane wiring. The
optional BGM interface circuit 530 distributes the BGM SO~RCE
signal to all station sets selected to receive it through the
backplane wiring, except when it receives a BG~ DISABLE signal
from the page card 400.
Referring specifically to Figure 7, the link card
circuit shown there includes a single passive port and multiple
active ports. The passive port comprises current detector cir-
cuit 702, which includes a DC current signal blocking trans-
former in the ANALOG LINK path and is constructed in a manner
similar to the current detector circuit in hotline B-port 238
in station card 200 (Fi~ure 4). The sensed DC signal current
from an active port of a seizing station card 200 will cause
the current detector 702 to generate an output voltage which is
fed to a series of voltage comparators 722, 724, 726, and 728
which will be successively triggered in response to sensed DC
signal currents of 1.6 ma, 3.2 ma, 6.4 ma, and a 14 ma pulse
(50 milliseconds), respectively, which cause the voltage output
54
117872Z
of current sensor 702 to increase to successively higher
levels. In response to a DC signal current indicating seizure
(1.6 ma) received from a station card active port on the ANALOG
LINK input to current sensor 702, a LINK DXP DC voltage signal
(-2v.) will be generated by comparator 722 and sent to all
station cards 200 which are also connected to the ANALOG LINK in-
put to current sensor 702. Simultaneously, cGmparator 722 applies
a SEIZE signal to request logic circuit 744, which in turn
generates a LINK REQUEST signal which is sent to the register
card(s) 600. If the register or registers are in use, no LINK
CONNECT signal will be returned. In a system with more than
one register card 600, only one can be in the ready status, and
the other(s) will all be either in use, i.e., connected to a
link circuit 700, or in standby status. The ready register
becomes connected in response to the LINK REQUEST signal, and
sends a LINK CONNECT signal to connect logic circuit 742, and
a LINK DATA ENABLE signal and a LOAD ADDRESS signal to AND
gate 740, which responds by enabling the tens latches 748 and
the units latches 752. The connecting register will then send
back an 8-bit address, four bits to tens latches 748 and four
bits to units latches 752, representing either a decimal 98
or 99 which identifies the connected register (in a two-register
system) to which a register crosspoint REG 1 or REG 2 is to be
closed. The binary-to-decimal converter circuits 712 and 714
decode the binary outputs of level shifters 750 and 74~, re-
spectively, so tha~ B/D converter 714 provides an input to
AND logic circuit 710 representative of the first register-
identifying digit (9) and B/D converter 712 provides an input
to AND logic circuit 710 representative of the second register-
identifying digit (8 or 9). These two inputs will cause ANDlogic circuit 710 to generate either a REG 1 GATE signal or a
REG 2 GATE signal to close either the REG 1 crosspoint to a
11787Z'~
first register or the REG 2 crosspoint to a second register.
Dial tone is now passed from tone card 500 via the connected
register 600 through the closed REG crosspoint and over the
ANALOG LINK BYPASS to indicate to the caller that he may now
send dial signals to identify that passive port which he wishes
to seize. ~ither DTMF or outpulse dial signals will be trans-
mitted via the ANALOG LINK BYPASS around current sensor 702,
and current sender 704 through the closed REG crosspoint to
the connected register 600, which decodes the dial signals,
puts them in binary form, and decides whether or not the number
is valid. If the number is not valid, e.g., there is no passive
port to which the dialed number has been assigned, the REORDER
TONE from tone card 500 is sent via the connected register 600
over the ANALOG LINK path through a designated internal cross-
point 706, which is closed in response to a reorder crosspoint
address (97) sent by the register 600 to the latches 748, 752,
which have been re-enabled by AND gate 740 to receive the re-
order crosspoint address, which replaces the invalid address.
This new address displaces the register-identifying address
(97 or 98) and thereby causes the REG crosspoint to the register
to re-open. Also, a REORDER signal is sent to start kick-off
logic circuit 716, which generates a 20 millisecond pulse sig-
nal TKO after a predetermined period of time (e.g., about 8
seconds), in response to which the current detection circuit
702 causes the LINK DXP output of comparator 722 to go to +2v.
for 20 milliseconds, which causes the seizing active port to
cease transmission of its ~C seize current signal. As a result,
the LINK DXP signal goes to +2v. to indicate that the link is
idle, and the SEIZE signal to request logic circuit 744 is ter-
minated, causing termination of the LINK REQUEST signal. Thecaller may release and reseize the link before kick-off occurs.
56
~ ~ 787Z'~
If the called number is valid, the register 60~ gener-
ates a LOAD MODE signal in addition to the previously-generated
LINK DATA ENABLE and LOAD ADDRESS signals to cause AND gate 738
to enable the mode latches 736 and the current mode latches 754.
The register is preferably designed to recognize the following
number groups as valid and to issue the oppositely-listed
current mode signals and address data:
Current
~alled Numbers Mode Signal Link Data 10s Link Data Uni~
10 30-89 decimal 0 binary 3-8 binary 0-9
130-189 decimal 1 binary 3-8 binary 0-9
230-289 decimal 2 binary 3-8 binary 0-9
917-930 decimal 9 binary 1-3 binary 0-9
991-996 decimal 9 binary 9 binary 1-6
Thus, a dialled number 56 will cause a logic level signal rep-
resentative of a decimal O generated in the register to be sent
by the register to the fi~st input to the current mode latches
754 via the first link data units line, thereby providing a
SEIZE signal to mode control circuit 730. The absence of a pre-
fix number indicates that an internal call is being made and canbe answered handsfree. The first address digit is a binary-
coded 5 which is fed to tens latches 748, and the second address
digit i5 a binary-coded 6 which is fed to the units latches
752. As another example, a dialled number 148 will cause the
register to send a logic level signal representative of a
decimal l generated in the register to the second input to the
current mode latches 754 via the second link data units line,
thereby providing an ICM ~ING signal to mode control circuit
730. The prefix number l indicates that an internal call is
being made and must be answered via the called party's handset.
The first and second address digits are a binary-coded 4 and
57
~787ZZ
binary-coded 8, which are fed to the tens latches 748 and
units latches 752, respectively. A third example is the case
of a dialled number 265, which will cause the register to send
a lo~ic level signal representative of a decimal 2 generated
in the register to the third input to the current mode latches
754 via the third link data units line, thereby providing a
STEAL signal to mode control circuit 730. The prefix number 2
indicates that the caller is effecting a "call steal", i.e.
answering a call that is coming ln at another station set, some-
times referred to as alternate-point answering. In this case,
the address data (binary-coded 6 and binary-coded 5) identifies
the station set to which the incoming call is directed. The pre-
fix number 9, when dialled before the numbers 17 through 30, in-
dicates that the caller wishes to seize a CO line through one of
the active ports comprising the paired CO crosspoints labelled
LINES 17-30 ANLG and LINES 17-30 DXP, and causes the register to
send a logic level signal representative of a decimal 9 generated
in the register to the fourth input to the current mode latches
754 via the fourth link data units line, causing a CO signal
to be sent to mode control circuit 730. The prefix 9, when
dialled before the numbers 91 through 96, indicates that the
caller wishes to seize one of the passive ports in the page
card 400 via one of the group of active ports comprising the sin-
gle line internal crosspoints 706 labelled PAGE 1, 2, 3, 4 and 5
and ALL PAGE. As before, the register sends a logic level
signal representative of a decimal 9 generated in the register
to the fourtb input to the current m~de latches 754, which in
turn provide a PAGE signal to mode control circuit 730. There
may also be a special single-digit number such as 0 which is
frequently dialled, e.g., to reach the operator at an attended
station in the system. The register(s) will interpret the 0
as requesting transmission of a two-digit a~dress (90) which
11787'~'~
will cause the link to close the internal crosspoint labelled
OPR to the operator's station.
The mode latches 736 receive a single input signal
pulse from the register at their second input simultaneously
with the logic level input to current mode latches 754, causing
a constant, inverted output ~ to be fed to called station
response timer 734 which in turn activates busy test logic
circuit 732 for a predetermined period of time (e.g., 2.5
seconds). During this time period, if no CALL B~SY signal is
received from the DXP detection circuit 718, busy test logic
circuit 732 will generate no output, but at the end of the time
period it will generate a CSSE (called station send enable)
signal, thus enabling current sender (mode) control logic
circuit 730 to generate a control voltage output to current
sender 704. Then, in response to inputs either from the voltage
comparators 724, 726 or 728 or from current mode latcl~es 754,
mode control logic circuit 730 will alter its normal DC output
(+8v.). In response to a logic level SEIZE, ICM RING, CO/PAGE
or STEAL input signal from current mode latches 754, mode control
logic circuit 730 will generate a DC voltage output of ~7.2v.,
+6.5v., +7.2v., or +6.5v., respectively, which will in turn
cause current sender 704 to generate a DC output current of
1.6 ma, 3.2 ma, 1.6 ma, or 3.2 ma, respectively, which is trans-
mitted via a closed crosspoint in arrays 706, 70~ to the passive
port to be seized. If the passive port is in the page card 400,
or is the link B-port 240 of a station card 200, the DC voltage
signal indicating seizure (-2v.) or, in the case of the station
card, pre-emptive seizure (-4v.), will be sent back to the link
7Q0 over the single conductor on which the DC si~nal current
effecting seizure (1.6 ma) is sent to the page card or link B-
port, and will pass through the closed crosspoint (one of the
59
1~,7872Z
group from PAGE 1, 2, 3, 4, 5, ALL PAGE, and STA 30 through
STA 89) on the STA COMMON DRAIN conductor to DXP detection
circuit 718 during the time period in which the busy test logic
circuit 732 is activated. In response to either -2v. or -4v.,
which indicate a seized or pre-emptively seized passive port,
respectively, the CALL BUSY signal will be generated by the DXP
detection circuit 718, in response to which the reset logic
circuit 720 clears the address latches 748, 752 and the busy
test logic circuit 732 generates a BUSY TONE ENABLE signal,which
starts the kick-off logic circuit 716 and is fed as an input to
AND logic circuit 710. The address latches 748, 752 now hold
the 00 address, which is the address of the BUSY TONE crosspoint.
In response to this address and the BUSY TONE ENABLE signal,the
AND logic circuit closes the BUSY TONE crosspoint to pass the
busy signal from the tone card via the ANALOG LINK path to the
caller's station card 200 and thence to associated station set
100. The caller must then either release the link before gen-
eration of a TKO signal pulse and then reseize it or another
link, or he will be kicked off the link upon generation of the
TKO signal by logic circuit 716. Upon either release or kick-
off, the SEIZE signal to request and connect logic circuits 744
and 742 will be terminated, causing initiation of the LINK RE-
S~T signal to reset logic circuit 720, which responds by issuing
both lSODE REG R~SET and ADDR REG RESET signals to latches 736,
754 and 748, 7~2 respectively. The address latches 748, 752
have already been cleared in response to the ~ALL BUSY signal
to the reset logic circuit 720.
If a line card 300 is seized through a pair of cross-
points 703, e.g., the pair labelled LINE 17 ANLG ~nd LINE 17
DXP, the DC voltage signal from the line card passive port is
received via the latter (DXP) crosspoint and fed via the CO~:~
DRAIN LINE DPX connected from all the drain electrodes of the
~ ~.7872Z
digital crosspoints labelled LINES 17-30 DXP to the DXP detec-
tion circuit 718, which responds in the same manner as it does
to the DC voltage signals received from the link B-port of a
s~ tion card over the STA COM~ON DRAIN conductor, as previously
described.
If the passive port seized by link 700 is in a line card
300, it is possible for the calling party to effect multi-line
conferencing (seizing of a second line card 300), flash signal-
ling (breaking loop current long enough to drop the called
party while retaining the line), placing the called party on
hold, and privacy release,all in response to DC current signals
to the current detector 702 which will respond thereto by gen-
erating a voltage output to voltage comparators 724, 726 and
728 as described earlier herein. Those voltage comparators
provide their outputs to mode control logic circuit 730, which
responds when enabled by the CSSE signal to cause current sender
704 to generate a DC signal current at the same level as the DC
signal current received by current detector 702.
Upon termination of a completed call, internal or external,
the calling party's station card 200 ceases to send DC signal
current to the link 700, causing the output of current sensor
to drop below the triggering threshold of voltage comparator
722. Thus the LINK DXP signal goes to +2v., indicating that
the link is again seizable, and the SEIZE signalto re~uest
logic circuit 744 is terminated. The register has previously
been disconnected in response to signal T2 from mode latches
736, which overrides the SEIZE signal from comparator 722.
The LINK RESET signal is now generated to cause reset logic
circuit 720 to generate MODE REG RESET and AD9R REG RESET to
clear all of the latches 736, 748, 752, and 754.
61
1~,787Z'~
Referring specifically to Figure 8, the register cir-
cuit 600 shown there may be connected to any number of link
circuits 700, e.g., four, as shown, any one of which can send a
LINK REQUEST signal to link searcb circuit 628, which responds
to that signal by sending a CO~IMON LINK REQUEST signal to reg-
ister control timing circuit 626. If it is not in the ready
status, circuit 626 will not send SEARCH PULSES, which have the
same width (2 milliseconds) and f.equency (250 hz) as the output
of clock generator 610, to circuit 628, and the register's tri-
state buffers 630, 632, 634 and 636 will not be enabled to pass
data to the link. If it is in the ready status, circuit 626
will send SEAR~H PULSES to the link search circuit 628, which
responds by sending a constant logic level ENABLE signal to
tri-state buffer 630 and by transmitting a logic level LINK
CONNECT signal to the specific link identified by the data out-
put from link search circuit 628 to the buffer 630. A LINK
FOUND signal is also sent to timing circuit 625, which responds
by sending an ENABLE signal to tri-state buffers 632, 634 and
636. Buffer 632 then provides a logic level LINK DATA ENABLE
signal to the specific link identified by the data output from
link search circuit 628, and buffer 634 sends a LOAD ADDR signal
to all the link circuits in the system, to which its two outputs
are commonly connected. Timing circuit 626 then sends a SEND
REG A~DR signal to output logic circuit 622, causing it to feed
the register's stored two-digit address, (97 or 98) to the
output tri-state buffer 636, the first digit being sent in four-
bit binary code to the link data tens inputs, and the second
digit being sent in the same code to the link data units inputs.
The timing circuit 626 then sends the SEND REG ~ODE signal to
output logic 622 and subsequently terminates the E~ABLE signa]
to buffers 632, 634 and 636 and sends (l) the DIAL TONE &
62
~787Z2
DIALING signal to the register reset and time-out circuit 606
to enable it to generate an output and (2) the inverse of that
signal to L~D 642 to energize it. ~eanwhile, the link 700
closes the REG crosspoint, through which its ANALOG LINK BYPASS
conductor is connected to the analog decoupling and current de-
tect c~rcuit 60~, which normally receives the DIAL TONE ENABLE
signal from register reset and time out circuit 606, and con-
sequently allows its DIAL TON~ input from tone card ~00 to pass
through the link 700 to the seizing station card 200 and its
associated station set 100. Dial signals may now be received
by the register 600 from the station set 100 via the station
card 200 and link card 700. Both dual-tone multi-frequency
(DTMF) dial signals and dial pulse train signals are received
by analog decoupling and current detection circuit 602, which
incorporates a transformer with one winding connected to the
link circuit(s~ 700 in the system, and the other winding conn-
ected to the tone filtering and decoding circuit 612. The
current detector may be constructed in a manner similar to the
current detector in the hotline B-port of station card 200
(Figure 4). DTMF signals are converted into four-bit binary
tone data by the decoder 612, and that data is fed to an up
counter 614 which, in response to a PRESET sigDal generated by
control logic 608 in response to the TDV (Tone Data Valid) signal
from decoder 612, is enabled to hold each dialed digit for trans-
mission to the binary-to-decimal decoder 616 in the same sequence
in which the binary-coded digits were received. The digit assign-
ment control logic 608 is normally in a waiting state, and is
enabled either by the TDV signal from decoder 612 when DTMF
dial signals are received, or by the B signal (inter-digit
time signal) from outpulse filter 604 when dial pulse train
~ignals are received. Then, the logic circuit 608, under
63
~,~787Z'~
the timing control of clock 610, causes the first digit to be
received by the B/D decoder 616 from counter 614. While it is
held in the B/D decoder 616, the first digit is tested for val-
idity by the control logic 608. If the first digit is a 0, 1,
2 or 9 (prefix code numbers), it is not passed to invalid dial-
ing trap circuit 620, but is held in function latch 618. If
the first digit is not a 0, 1, 2 or 9, it is passed to trap
circuit 620 in the form of a logic level signal on one of ten
conductors representing decimal numbers 0 through 9 in response
to a control logic 608 signal to trap circuit 620, which in turn
generates the SEND REORDER ADDR to output logic 622. This
command is executed by sending the reorder address (97) stored
in hardwired memory 624 through buffer 636, which has again
received an ENABLE signal from control timer 626 in response to
the SEND REORDER ~DDRESS signal, to the link address latches
748, 752 in response to the SEND MODE and SEND ADDR signals
sent in sequence to the output logic 622. The control timer
then resets itself, and sends the RESET IDLE signal to link
search circuit 628. As the control timer 626 goes through
these steps, it causes status indicator LED 644 to be momen-
tarily energized, followed by constant energization of LED 638
until the register status is changed by data received from
another register in the system.
The control logic 6~8 will cause each digit in a dialed
number to be passed in sequence to B/D decoder 616 for validity
testing, and the sequence of events described above will be
carried out in response to any invalid digit.
If the dialingnumber is valid, trap 620 sends a DIALING
DONE signal to register control timing circuit 626, which
responds by again sending an ENABLE signal to buffers 632, 634
and 636, and then providing the SEND MODE signal to output
64
~17872~
logic 622 to cause transmission of the logic level output repre-
sentative of a 0, 1, 7 or 9 from function latch 618 via the
appropriate one of the link data units paths through buffer
636 to the connected links' inputs to current mode latches 754.
Simultaneously, a pulse is sent by output logic 622 via a pre-
determined link data tone path through buffer 63~ to the conn-
ected links' inputs to mode latches 736. Register control
timing circuit then transmits a SEND ADDR signal to output logic
622, causing the address held in counter 614 to be sent through
output logic 622 and buffer 636 to the link address latches 748,
752. The register control timer 626 then sends a RESET IDLE
signal to link search circuit 628, which in turn terminates
the ENABLE signal to buffer 630, which responds by terminating
the LINK CONNECT signal to link connect logic 742.
When the dialed signals received through the link are
current pulse trains, the current detector 602 generates
corresponding digital logic level voltage pulses which are pas-
sed through pulse filter 604 to counter 614, which counts the
pulses and holds the digits represented thereby in four-bit
binary code for transmission to the B/D decoder 616 in the same
sequence in which the digits' respective pulse trains were
received, and in the same manner as described above in the case
of DT~IF dial signals.
The pulse filter circuit 604 generates four logic level
voltage outputs A, B, C and D which are fed to reset and time
out circuit 606 along with the TDV (tone data valid) signal
from tone decoder 612. The DIAL TONE ENABLE signal is generated
only when the A, B, D and TDV signals are logic 0s and C is
logic 1. Signal A is the filtered off-hook signal, which goes
high after receipt of the first dialed pulse and then goes lo~
1~.7872Z
during each pulse. Signal 8 is the inter-digit time signal,
which is high be~ each pulse train and low during each pulse
train. Signal C is the inverse of signal A, i.e., it is a vol-
tage duplicate of the dialed current pulse trains. Signal D
is the on-hook terminate signal, which is a logic 0 generated
when the caller's station set is on-hook, and thereby resets
the register. The TDV signal is normally low, and goes high
during each valid DTMF signal received. The signals A, B and
TDV are all utilized to trigger reset and time-out circuit
606 after it has been enabled to issue an output by the DIAL
TONE & DIALING signal from control timer 626. Specifically,
signal A triggers the timer 606 which measures the time from
its receipt of the SEND REG MODE signal from control timer
626 until the receipt of the first dialed signal (DTMF or pulse
trains). If this time period exceeds a predetermined maximum
(e.g., 10 seconds), the circuit 606 will cause the control
logic circuit 608 to send a signal to the trap circuit 620,
which responds by issuing the SEND REOP.DER ADDR signal. The
sequence of events described earlier will ensue. The B signal
triggers the timer 606 which measures the period between dialed
pulse trains. If that period exceeds a predetermined maximum
(e.g., 10 seconds), the circuit 606 causes generation of the
SEND REORDER ADDR in the manner described above. Signal C has
only the function of combining with signals A, B, D and TDV to
cause the circuit 606 to generate the DIAL TONE ENABLE signal.
Signal D also causes the termination of the SEND REORDER ADDR
signal by causing circuit 606 to terminate the signal it sent
to control logic 608 in response to signal A. The TDV signal
triggers the timer 606 which measures the period between the
termination of each DTMF signal and the initiation of the
following DTM~ signal. If that period exceeds a predetermined
66
~ ~8~72Z
maximum (e.g., 2 seconds), the circuit 606 generation
of the SEND REORDER ADDR signal as described above.
The register control timer 626 is connected to at least
one other register, with which it exchanges data indicating
register status. Specifically, if the register shown in the
drawing is in the ready status, the SEARCH ENABLE OUT signal
is present, and the SEARCH ENABLE IN signal from the other
register is absent, indicating that it is in the standby status.
The inverse is also true, i.e., if the register sho~n is in the
standby status, the SEARCH ENABLE OUT signal is absent, and the
SEARCH ENABLE IN signal from the other register is present,
indicating that it is in the ready status. If the register
shown is sending mode or address data to a link, the DATA LINK
ENABLE OUT signal is present and will prevent the other register
from sending mode or address data. If the other register is
sending mode or address data to a link, the DATA LINK ENABLE IN
signal is present, and will prevent the register shown in the
drawing from sending mode or address data. This mutual exclu-
sion feature is necessary because of the common data output
connections of all registers to all links. This complete
signalling arrangement causes the registers to share their
workload approximately equally, since the register which is
idle while the other is functioning and will handle the next
link request.
Referring specifically to Figure 9, the page card circuit
shown there includes five passive ports, one in each of zone 1,
zone 2, zone 3 and zone 4 circuits and one in the all-call
circuit. In the several zone circuits, each of which is iden-
tical to the zone 1 circuit shown in detail, a DC current sig-
nal-blocking transformer 402 has a shunt resistor 404 across
67
117872'~
one winding, both being connected to current sensor circuit
408, which is constructed in the same manner as the combination
current sensor-voltage sender in the link B-port (Figure 4),
and responds to a DC seize current (1.6 ma) received from an
active port of a station card 200 or link card 700 to generate
two voltages,one to the associated crosspoint(s) in the link
card (s) 700, and another as an input to voltage sender 410,
which in turn generates a DC voltage signal (-2v.) indicating
seizure to all of the station cards 200 to which the output of
voltage sender 410 is connected. A paging message can then be
transmitted from the seizing station card 200 or link card 700
through transformer 402, volume-controlling variable resistor 406,
resistor 412, normally-conductive MOSFET 414, and amplifier 416
to the group of station cards selected to form zone 1, each of
which receives the paging message as the PAGE input to the B-
port switching circuit 246. OR gate 422 also has received
the voltage output of current sensor circuit 408 as an input
which causes generation of the BG.~.~ DISABLE signal, which is fed
to the BGM interface circuit 530 on the tone card 500 (Figure 6)
to interrupt the transmission of background music until the
page card passive port is no longer seized. In the station card
200 associated with the station set 100 from which paging is
initiated, the PAGE ENABLE signal to JCT FET 291 in the B-port
switching circuit 246 (Figure 4) is terminated for as long as
the page button is depressed in the station set 100, so as to
block transmission of the paging message to the originator's
station set.
When the all-call passive port is seized b~ a DC current
signal (1.6 ma) from an active port of a station card 200,
current sensor 430 (identical to 408) generates one output
voltage to the associated crosspoint in the link 700 cards, and
68
117872'~
another voltage which causes generation of a DC voltage signal
(-2v.) by voltage sender 432, both voltages indicating seizure
of the all-call circuit to all the station cards 200 and link
cards 700 to which it is connected, and also causes generation
of the BGM DISABLE signal by OR gate 422. The output of voltage
sender 432 is fed as an input to OR gate 440, causing it to
render MOSFET 414 (and its counterparts in zone circuits 444,
446, and 448) non-conductive. Thus, an all-call page will
pre-empt a page to any single zone. The all-call page message
is received from the seizing station card 200 and transmitted
through transformer 424, normally-conductive MOSFET 434, and
resistor 438 to all of the zone circuits, which receive and
transmit the message to the station cards 200 in their respective
zones, e.g.,in the zone 1 circuit through resistor 420 to the
input of amplifier 416, the output of which is fed to the
station cards 200 in zone 1.
When the NR ENABLE signal is received from the night
ring control circuit 526 on tone card 500 (Figure 6), it is
fed as an input to OR gate 440, to inverter 436, and to JCT
FET 442. Consequently, any paging message is blocked because
MOSFET 414 and its counterparts are all driven non-conductive
by the output of OR gate 440, and the MOSFET 434 in the all-call
circuit is driven non-conductive by the output of inverter 436.
The CO AUDIBLE TONE is passed through JCT FET 442 and resistor
438 to all of the zone circuits (l) until the incoming call is
answered, thereby terminating the NR ENABLE signal as a result
of termination of the INCOMING CALL ENABLE to the tone card 500
because of termination of ringing detection in the line card
circuit 300, or (2) until the caller terminates the call before
it is answered, thereby causing the same sequence of signal
termination as in (1) above.
69
1~7872'~
Referring specifically to ~igure 10, the conference
card circuit 600 shown there consists of a passive port which
is of essentially the same construction as the hotline B-port
238 (Figure 4), the differences being that it does not provide
an outgoing communication path and, ~hen seized, causes the DC
output of voltage comparator 618 to go from +2v. to 0v. Thus,
the conference card circuit 600 acts only as a meeting point
for internal conferences, i.e., it is a passive port which
enables connection of all active ports which are connected to
it to each other. Once this circuit is seized by a first
caller, who has previously requested (e.g., by paging or by
intercom call) several other system users whose station sets
100 and station cards 200 have this feature to meet him by
actuating the conference button or key in each of their station
sets, the visual indicators associated with the conference
buttons will be energized in response to the 0v. DC output
voltage from voltage comparator 618, indicating that the con-
ference card circuit is in use. Thus, anyone whose station set
100 and station card 200 has this feature, but who has not been
requested to join the conference, will be aware that the con-
ference card circuit is in use and that he should not use this
feature. Ho~ever, any such uninvited system user can join in
a conference, since any number of station cards 2Q0 can seize
the conference card circuit simultaneously. There is no pro-
vision for exclusion, except by selection of the station sets
100 and station cards 200 which are to have this feature.
The four wire arrangement used in the preferred arrange-
ment of the key telephone system is illustrated in FIG. 11,
which shows in block diagram form the general aspects of any
four-wire path. Four conductors, 1,2 an~ 3,4 are shown connect-
~ 7872Z
ing a station circuit 10 and a key telephone station set 20.
Each conductor pair is terminated by a transformer. Trans-
formers Tl and T2 terminate the conductor pair 1,2 and con-
ductor pair 3,4 in key telephone set 20; transformers T3 and
T4 terminate conductor pair 1,2 and conductor pair 3,4 in
station circuit 10.
Each transformer has a center tap connection on the
transformer winding connected to the conductor pair. Center
tap connections are located at the telephone station set 20
(Cl and C2) and at the station circuit 10 (C3 and C4). A
"phantom circuit" is created via the center tap connections
C1 and C2, through the conductors 1, 2, 3, 4, to the center
taps C3 and C4 or transformers T3 and T4. This arrangement
creates a virtual third pair, known as a phantom pair,
because in a closed circuit connected to center taps C3 and
C4 of T3 and T4 and to center taps Cl and C2 of Tl and T2,
the current applied at a center tap point will divide at the
center tap connection, flow over two conductors, and be
received in recombined form at the center tap at the other
end.
Connected to both conductor pairs 1,2 and 3,4 at each
end is circuitry necessary to create a complete communication
channel. For exampie, at the key telephone station set 20,
circuit pairs 1,2 and 3,4 are inductively coupled by transformers
Tl and T2 to a function control network 30, controlled by a
programmed digital computer 40. The function control network 30
provides a communication path to the telephone handset hybrid
network 31 or to the speakerphone 32 of the key telephone station
set 20. Connected to the side opposite pair 1,2 of transformer
T3 in station circuit 10, is a conductor pair 5,6 for connection
to a central office line. Connected to the KSU side of trans-
71
1~.7872~
former T4 is a conductor pair 7,8 which may be connected via
switching circuits in the control unit to other key telephone
set conductor pairs. Thus, two independent voice paths via the
four conductors 1,2,3,4 are provided in the circuit arrangement
shown in FIG. 11.
Superimposed upon the voice paths such as Pl are means
for supplying power from the key service unit to the telephone
set 20 via the phantom pair comprising the center tap connections
C3, C4 through the balanced conductors 1,2,3,4 to the center
tap connections Cl and C2 of transformers Tl and T2. D.C.
voltage sources 110, 112, each of voltage El, are connected in
series with resistors Rl and R2 to center tap connections C3 and
C4. Digital data signals from the station circuit 10 are
superimposed on the phantom pair with the D.C. level supplied by
voltage sources 110, 112 by modulator 114.
In telephone station set 20, receiver circuit 150
responds to the D.C. voltage pulses appearing between center-tap
connections Cl and C2 of transformers Tl and T2 and produces a
data signal proportional to the data modulated by modulator
circuit 114 in station circuit 10. The output from receiver
150 is applied to digital computer 40 in the station set 20 for
controlling function control network 30 and switch and indicator
unit 50 within the station circuit 20.
An A.C. high impedance element 600 is connected in
series with voltage regulator 500 and constant current sink 300
to provide a circuit terminating phantom line 1,2 and 3,4 so as
to substantially eliminate reflections on the line 1,2 and 3,4.
Data is transmitted from the station set 20 to the
station circuit 10 over conductors 1,2,3,4 by applying data
pulses to modulator 200, which switches a resistor 201 in and
out of parallel connection with the phantom circuit connected
li787Z'~:
to center taps Cl and C2, the current of which is being supplied
by the station circuit 10. Because constant current sink 300
draws constant current from the closed circuit, and because
resistor 201 is switched in and out of parallel connection with
the constant current sink, current modulation in synchronism
with the station set 20 data signals is applied on conductors
1,2,3,4.
The current pulses are sensed at the station circuit 10
by receiver 400 by comparing the voltages across resistors Rl
and R2 which are proportional to current changes through them.
The data produced by receiver 400 is in response to the current
modulation imposed by modulator 200 in station set 20. Data
signals received by receiver 400 are then applied to logic
circuits within the central switching and control unit 1010 of
key service unit 1000 to provide information with respect to the
status of different switches of key telephone set 20. For
example, the data being supplied by digital computer 40 within
the station set 20 to modulator 200 includes the status of
different line keys in the station set or the status of an
indicator, the status of a hold key or privacy release key, etc.
Power is supplied from the station circuit 10 to the
station set 20 by applying D.C. current from the D.C. sources
110, 112 via the phantom circuit to station set 20 where it
flows through voltage regulator 500. Voltage regulator 500
divides and regulates the D.C. voltage supplied via the phantom
circuit and applies the divided and regulated voltage levels to
circuits within the station set 20.
FIGS. 12A and 12B illustrate a preferred format for the
data pulses which are applied to conductors 1,2,3,4 by the
station circuit 10 and the key telephone set 20. Each period of
time T, typically 20.4 milliseconds, is divided into thirty-four
73
~787Z'~
600 microsecond segments. The first word, called the "Oth" word,
is used as a synchronizing interval by the station set 20 digital
computer to determine the start of the periodic word sequence
of "message." The next 33 time segments, or words, are used in
sending and receiving data between station circuit 10 and
telephone set 20.
Each word is divided into five intervals. Although in
general the intervals may be divided equally in time for each
word, the preferred format in the key telephone system in which
the invention is used requires that the third, fourth and fifth
intervals each to be equal in time length, L, while the first
interval is specified to be of 1/2 L time length. The second
time interval is specified to be of 3/2 L time length. Time
length L is specified to be 120 microseconds, so as a result,
time intervals one through five, when summed, equal 5L for a
total of 600 microseconds. The data from the station circuit 10
to the station set 20 is applied during the first two of the
intervals. Data returning from the station set 20 is applied
during interval four. Intervals three and five remain idle.
Each word is designated to correspond to a particular
function or line of the station circuit 20. The key service
unit 1000 logic circuitry 1011 then scans each function once
every 20.4 milliseconds and applies information via the data
path to the station set 20 during the first and/or second interva]
of a word. The digital computer 40 in the station set 20
receives the data and uses it to control corresponding
functions, such as connection of a speakerphone, or physical
equipment, such as an indicator, in the station set. Current
pulse information regarding the status of a particular function
or element is transmitted during the fourth interval of each
74
:~1787Z'~
word from the station set 20 via the four conductor 1, 2, 3, 4
phantom circuit and is received in the station circuit 10 for
use by the central switching and control circuit 1010 in making
logic decisions for controlling the various elements and/or
functions of station set 20.
FIG. 12A illustrates how information pulses from
station circuit 10 to station set 20 are applied. The first
voltage pulse in time slot "1" (e.g., T 1 1 ~ T 2 1 ....T33 1) is
always present, thereby allowing digital computer 40 in station
set 20 to determine exactly when a new word is beginning. In
any word the station circuit 10 applies a "1" pulse during the
time interval "2" by maintaining the voltage pulse high. That
is, as illustrated for "Word 2" of FIG. 12A, the voltage pulse
extends from T2 1 through T2 2 without returning to zero. In
any word, the station circuit 10 applies a "0" pulse during the
time slot "2" by removing the voltage pulse existing during the
time slot "1". FIG. 12A illustrates how a "0" pulse is applied
during Word 1 and Word 33, where during the intervals Tl 2 and
T33 2 no voltage pulse is applied.
FIG. 12B illustrates how current pulses from the station
set 20 are impressed on the phantom circuit conductors 1,2,3,4
for reception by station circuit 10 logic circuitry. A current
pulse applied during the fourth interval of a word, as in Word 1
of FIG. 12B, indicates that a "1" is being transmitted from
station set 20 to control unit 10. The absence of a current
pulse applied during the fourth interval of a word, as in word 33
of FIG. 12B, indicates that a "0" is being transmitted from
station set 20 to station circuit 10.
In the key telephone system in which this invention is
used each particular word of the time period T is used to provide
11787Z'~
information for the control of and/or status of line keys,
indicators, hold keys, speakerphone circuit, etc. Although
thirty-four words are shown in this specification for purposes of
demonstrating the preferred embodiment of the data format of the
key telephone system, any number of words may be used to corres-
pond with the number of keys, indicators, and auxiliary circuits
existing in a particular key telephone system.
Another feature of the data format used in the key
telephone system relates to the manner in which information as
to the status of the hookswitch and dial pulsing of the telephone
station set 20 is transmitted to the key service unit 1000. As
illustrated in FIG. 12B, during each word, short width current
pulses during time interval two, are transmitted from the
telephone station set 20 over the phantom circuit of conductors
1,2,3,4 to the key service unit 1000, whenever the hookswitch
is closed. Time interval two is selected in the preferred em-
bodiment of the invention so that the frequently occurring hook-
switch current pulses are generated during the long time interval
two of each word, which is 3/2 L of the time length. This
design facilitates reception of the hookswitch pulses in the key
service unit, because the relatively short hookswitch pulses do
not overlap the ends of the time interval. A hookswitch signal
is applied from the station set 20 under two conditions: ~1) when
the status of the telephone station set is "on-hook" (on-hook
status occurs when the hookswitch is open and the speakerphone
is not in operation) or (2) when a dial pulse from a rotary
dial (or an electronic dial which generates dial pulses)
associated with the telephone station set is generated.
Thus, when the station set has an "on-hook" condition,
current pulses during the second interval of each word are
76
1~7872'~:
transmitted and continue to be transmitted until the on-hook
status is terminated (by the handset being taken "off-hook" or
by the speakerphone being turned on). During dial pulse signal-
ling, the current pulses are applied during the second interval
of each word during, but only during, the generation of each
dial pulse. The time period for each word of the data format,
illustrated in FIG. 12A, is sufficiently short with respect to the
length of a dial pulse that many "hookswitch" current pulses
are transmitted, one each during each of the words of the data
format. The presence or absence of current pulses received by
the key service unit 1000 in the second time interval indicate
that a dial pulse is being transmitted from the key telephone
set.
Thus, the data format of the key telephone system, in
combination with the four wire communication circuits, allows
telephone station sets adapted for dial pulse signalling or tele-
phone station sets adapted for frequency signalling to be
connected to rhe key service unit by means of the communication
circuit. Frequency signals are applied over one of the
communication channels 1,2 or 3,4 while dial pulse signals are
transmitted over the four conductor phantom circuits 1,2,3,4
by means of the data format as discussed above.
FIG. 13 illustrates the digital computer 40, indicated
in block diagram form in FIG. 11, and the external connections
to the microcomputer.
The preferred embodiment of the microcomputer in the
key telephone set 40 illustrated in FIG. 13 is the model
PPS-4/1 MM77 single circuit microcomputer system manufactured
by Rockwell International Corporation and described in Document
No. 29410-N42, Revision 1, July 1976, published by the Micro-
electronic Device Division of Rockwell International Corporation.
77
7Z'~
Microcomputer 40 receives data from receiver 150
(FIG. 11) on the "INT ~" lead, and applies signals to modulator
200 (FIG. 11) on the "Data 0" lead. Leads DI/00 to DI/09 and
leads RI/01 to RI/04 are used to access the switch matrix and
indicator matrix, schematically illustrated as key/indicator
array 50 and the function control network 30, schematically
illustrated in FIG. ll. Voltage input on lead VDD of microcom-
puter 40 is provided via a tap (not illustrated) from voltage
regulator 500. Other leads on the microcomputer 40 illustrated
in FIG. 13 are either not used or are not essential to the
understanding of how the microcomputer functions to control the
operation of the key telephone station set 20, in the key
telephone system.
FIG. 14 illustrates a switch matrix used in the key
telephone set of this invention which is periodically monitored
by the microcomputer 40. The switches are arranged in eight
columns and four rows. The switches in columns one through
seven are preferably non-locking switches; that is, when the keys
associated with the switches are depressed, the switches only
close while the keys are being pushed. Locking switches could,
of course, be used in another embodiment of the telephone set
of this invention. Switches in columns one through seven are
arranged on a key panel 50 as illustrated in FIG. ll. Switches
in columns 1 through 7 are associated with central office lines
and various functions which are incorporated in the key tele-
phone set of this invention as indicated in FIG. 16. The
switches in column 0 are not connected to the seven-by-four
key panel 50 on the face of the key telephone instrument (FIG. ll).
The switches in column 0, may be locking switches, or may be non-
locking, depending on their use, as will be explained in detailbelow.
78
117872;2
The switch matrix of FIG. 14 is arranged to conform
to the data format illustrated in FIGS. 12A and 12B. Of the
thirty-three words available for transmission of information
between the key telephone station set and the key service unit,
thirty-two of the words are associated with one of the switches
in the eight by four switch matrix. The additional word is
used for control purposes as will be explained below. The
function of the switch matrix of FIG. 14 is to present a signal
to the microcOmputer 40 in the key telephone set which can be
recognized and transmitted to the key service unit as a request
for a particular kind of service associated with one of the
switches in the matrix.
During the word associated with switch S4, the micro-
computer monitors the voltages on inputs designated as RI/01
and DI/01 to determine if switch S4 has been depressed. The
status of switch S4 is determined by microcomputer 40 during
word 4, by applying a positive 7.5 volt strobe pulse on lead
DI/01 while enabling lead RI/01. If switch S4 is open, a -7. 5
volt signal appears at point P4, because no current path exists
to drop the -7.5 volts of source E across the parallel resistors
R301 and R201. If switch S4 is closed and a ~7.5 volt pulse on
DI/01 is applied, the voltage at point P4 is approximately t7.5
volts because the -7.5 volts of source E and the t7.5 volt
pulse of DI/01 is dropped across resistors R201 and R301. Thus,
during word 4, if switch S4 is closed, a t7.5 volt signal is
applied on lead RI/01 and is sensed by microcomputer 40 for
transmission of a pulse during time segment 4 o~ word four, as
will be explained in detail below. During word five, a +7.5
volt pulse on lead DI/01 remains, but lead RI/02 is enabled to
sense whether or not the ~7. 5 volt pulse appears at point P5.
79
1~7872Z
All switches are sequentially sensed periodically according to
the format of FIG. 12. According to the above described switch
sensing scheme, microcomputer 40 can obtain input information
regarding the status of line and function switches of the key
telephone set for processing and transmission to the key service
unit.
FIG. 15 illustrates the LED matrix used to indicate the
status of each of the functions associated with switches of
column 1 through 7 and rows 1 through 4. Light Emitting Diodes
(LEDs) are used in the preferred embodiment of this invention
because of their extremely low power requirements, but other
embodiments of the visual indicator matrix could possibly employ
small light bulbs or equivalent devices. If it is desired to
illuminate, for example, the indicator associated with switch 4
(i.e., a key marked C.O. Line l-see FIG. 16) the LED of column
"A" and row "W" of FIG. lS is illuminated during, but only during,
word 4 of the data format. For example, the microcomputer
receives information from the key service unit that C.O. line 1
is active, and that the indicator associated with that line is to
be illuminated. During word 4, a pulse is received during the
second time segment (e.g., T2 4~ FIG. 12A). The microcomputer
responds by generating pulses on leads RI/05 and DI/01. These
pulses from the microcomputer, each of ~7.5 volts in value are
transformed by isolating circuits 100 and 110 to be -7.5 volts
on lead A and -12.6 volts on lead W. Application of these
voltages to LED 1 of FIG. 15 causes current to flow through it
for the duration of word 4.
It should be noted that even though LED 1 is pulsed
only during word 4, the period T of the data format assures that
it is illuminated once each period, or once each 20.4 milli-
seconds or approximately fifty times each second. To the human
~1787Z;~
eye, the indicator appears to be steadily lit, even though in
reality it is being pulsed for only about 600 microseconds out
of a period of 20.4 milliseconds. It is seen that the method
and apparatus of illuminating switch or key indicators of the
key telephone set yields tremendous economies of power, because
each indicator need not be continuously powered, yet to the
human eye, the indicator appears to be continuously illuminated.
FIG. 16 illustrates the functions assigned to each of
the switches of the switch matrix illustrated in FIG. 14.
Assignment of functions to switches is easily changed, because the
key of column 1 and row 4 (word 4) may be assigned to any central
office line connected to the key service unit. Likewise, the
key of column 1, row 4 (word 7) could be assigned a function
other than the "hold" function indicated in FIG. 16. For example,
if it were desired to designate the key or switch of column 6,
row 3 as the "hold" key, all that would be required would be to
lable key 26 as hold, remove the label from the key 7 and
designate word 26 of the data format to be associated with the
hold function. Each of the functions designated in FIG. 16 will
be described in detail below for an illustrative operation of the
key telephone set of this invention.
FIG. 17 illustrates the function control network 30
(see FIG. 11) which controls the handset hybrid network 31,
speakerphone 32, and dial 33. In normal use, the key telephone
set 20 of this invention connects its handset hybrid network 31
(hereinafter "handset") via the "A" path or conductors 1,2
through the key service unit switching and control unit to a
central office line designated by one of the C.O. keys illustrated
in FIGS. 14 ana 16. Path "B" is used ordinarily when an incoming
call is being received by the key telephone set from another key
81
1178722
telephone set in the key telephone system. An intercom call is
received and answered at the key telephone set via path "B" to
speakerphone 32 where the key telephone set user may receive the
caller's voice over built-in speaker 320 and transmit the user's
voice via microphone 321, both of which are components of
speakerphone 32.
In normal operation (handset 31 connected to "A" path)
the microcomputer 40 outputs a pulse on lead DI/08 which
is connected to the "C" input of integrated circuit
MC 14042 B (manufactured by the National Semiconductor
Corporation), hereinafter designated the "latch" circuit. When
a pulse is present on DI/08, the voltage state at RI/01 - RI/04
is transferred and held at outputs 0-3 of the latch circuit
(Q & Q). No input on lead C via microcomputer lead DI/08
causes the Q3 output lead to be low, and the Q3 output lead to
be high from this latch circuit. A high output on Q3 causes
field effect transistors FET 1 and FET 2 to conduct, thereby
connecting handset 31 to the "A" path and speakerphone 32 to the
"B" path. Field effect transistors FET 3 and FET 4 are turned
off because the output on lead Q3 is low.
When the key telephone set user desires to use the
built-in speakerphone 32, he may depress his speakerphone on/off
key (see FIG. 16, key 10) which, as explained below in the
description of the operation of the key telephone set, causes a
+7.5 input pulse on RI/04 at the time of the pulse on DI/08 from
microcomputer 40, which causes Q3 to be low and Q3 to be high.
When Q3 is low, FET 1 and FET 2 are cut off, disconnecting hand-
set 31 from the "A" path and speakerphone 32 from the "B" path~
Simultaneously, when Q3 is high, FET 3 and FET 4 are turned on,
connecting points P4 and P5, and P6 and P7, with the result
82
~7872'~
that handset 31 is connected to the "B" path, speakerphone 32
is connected to the "A" path.
The ke~ telephone set of this invention may be used
interchangeably with dial pulse signalling dials (as indicated in
FIG. 17 by circuit 33) or with frequency signalling dials (as
indicated in FIG. 17 by circuit 33'). Frequency dial signals are
applied over path "A" in the same manner as prior art
telephones. The dial pulses are applied, not via paths "A" or
"B," but as a sequence of "hookswitch" pulses transmitted to the
key service unit to be reconstituted as central office dial
pulse signals or to be used internally for intercom signalling.
The dial pulse signalling circuit 33 is controlled via an output
from microcomputer 40 via the latch circuit which continuously
applies an enabling voltage to transistor T33 during a certain
time after the telephone handset has been picked up or after
the speakerphone has been enabled, etc.
As shown in FIG. 17,during the make period of
breaker 35 (normal operation when no signalling is being con-
ducted), if transistor T33 is conducting (i.e. the dial is
enabled via latch output Ql), input A of "OR" gate 01 will be
driven to -7.5V. Input B of OR gate 01 will also be at -7.5 V
due to the "off hook" status of station set hookswitch H.S. Thus,
no output signal is applied to the microcomputer via lead
INT 1 and no hookswitch pulses are applied to the KSU in the
words of the data message.
During a dial break period (e.g., breaker 35 is open)
input A of OR gate 01 is driven to ~7.5 V via resistor R901;
thus the output of OR gate 01 will be at +7.5 V. The high
voltage applied to microcomputer input lead INT l via the output
of OR gate 01 causes the microcomputer to transmit hookswitch
signal pulses during each word of the message as long as the
83
1~787ZZ
dial pulse breaker 35 is open. Of course if the handset is on
hook, the hookswitch HS is open, a high output via input B of
OR gate 01 is applied to lead INT 1, and the microcomputer
continually transmits hookswitch pulses to the KSU.
As indicated previously, a hookswitch signal during
interval two of each word is applied from the microcomputer 40
via the phantom circuit to the key service unit under two
conditions: (1) when the status of the telephone station set is
"on hook" (when a hookswitch HS is open and the speakerphone is
not operational) or (2) when a dial pulse from a rotary dial is
generated. When the user picks up the handset, the hookswitch
HS closes and hookswitch pulses are terminated, except during
dialing, when pulses are generated by periodically opening a
switch, in the same manner as the hookswitch is opened when the
handset is "on hook."
Background music is applied to the speaker 320 of the
key telephone set from the key service unit via the "B" path.
When the switch 1 of the switching matrix illustrated in FIG. 16
is depressed, the microcomputer 40 sends a signal in word 1
of the data format to the key service unit indicating that back-
ground music is desired at the key telephone set, whereupon the
key service unit applies background music to path "B" of the
key telephone s~t requesting music, and applies a pulse in time
segment 2 of word 1 indicating to the microcomputer that the
music bypass circuit of FIG. 17 is to be activated. When the Q2
of latch circuit is high, the music signal on path B is applied
directly to the speaker 320, yet the microphone 321 is rendered
inactive because of the low signal on Q2 to the Bypass lead
connected to the gate FET 6.
84
~178722
The program listing of Table I which follows is
stored in microcomputer 40 of the preferred embodiment of
this invention. The ROM 3ddress with machine operation code, and
the assembly language listing of the program is included in
Table I. The assembly language instructions are explained in
detail in the manufacturer's publication, "MM77 System Product
Description," Document No. 29410-N42, July 1976, published by
Rockwell International Corporation, pp. 5-8.
~5
1178722
TABLE I - PROGRAM LISTING
COLUMN I COLUMN II
Machine Code Instruction Code Machine Code Instruction Code
taddress, (assembly (address, (assembly
command) language) command) langua~e)
ORG #080
0040 17 SYST LB #7 0080 00 LTOF NOP
0060 71 ROS 00A0 00 NOP
0050 00 NOP 0090 00 NOP
0048 00 NOP 0088 5C X
0044 00 NOP 0084 OA EOB #2
0042 03 INTOH 0082 76 LBA
0061 Cl T WASYN 00A1 2B SKBF
0070 97 TM D7 00B0 3C TL OFNR
0058 03 INTOH 0098 C9
004C Cl T WASYN 008C 4F LAI #F
0046 97 TM D7 0086 79 XAX
0063 03 INTOH 0OA3 OA EOB #2
0051 Cl T WASYN 0091 40 LAI #0
0068 B3 TM Dll 00A8 74 XAS
0054 48 LAI #8 0094 50 L
004A 74 XAS 008A OA EOB #2
0065 00 NOP 00A5 7A XAB
0072 00 NOP 0089 70 SOS
0079 40 LAI # 0 00BC 7A XAB
007C 10 LBL #5~ 009E 00 NOP
005E OD 00AF 41 LAI #l
006F 7E A 0097 7E A
0057 09 EOB #1 008B 5C X
004B 5C X 0085 49 LAI #9
0045 50 L 00A2 74 XAS
0062 7E A 00B1 07 G03 SAG
0071 11 LBL 51 00B8 50 L
0078 OD 009C 77 COM
005C 7E A 008E 7B IOA
004E 09 EOB #1 00A7 6F AISK #F
0067 5C X 0093 CB T #GO4
0053 50 L 0089 27 RB 4
0049 7E A 00A4 00 NOP
0064 12 LBL #52 0092 3C TL SRTl
0052 OD 00A9 FF
0069 7E A 00B4 00 G04 NOP
0074 09 EOB #1 009A 00 NOP
005A 5C X 00AD 3C TL SRTl
006D 50 L 00B6 FF
0076 7E A 00BB 4E CTAU LAI #E
007B 13 LBL #53 009D 5C X
005D OD 00AE 5C INCB
006E 7E A 00B7 54
0077 18 CB #8 009B 4D LAI #D
00~B 7B IOA 008D 5C X
004D B5 TM D5 00A6 5C INCB
0066 70 SOS 00B3 54
0073 71 ROS 0099 4B LAI ~B
0059 8D TM D3 00AC 5C X
006C F8 T047 0096 5C INCB
0056 10 LB #8 00AB 54
006B 49 LAI #9 0095 47 LAI #7
0055 74 XAS 00AA 54 XNSK
006A 40 LAI #0 00B5 C4 T CTAV
86
11787ZZ
TABLE I - PROGRAM LISTING (cont.)
COLUMN I COLUMN_II
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address (assembly
command) language) command) language)
0075 00 NOP 00BA OE EOB #6
007A 3A TL SRTO OOBD 40 A13 LAI #0
007D D5 OOBE 54 XNSK
007E 03 WASYN INTOH OOBF C2 T A13
007F Cl T WASYN 009F 3E TL WASYN
005F 9A TM D4 008F Cl
004F FF T SYST 00C0 03 SRTl INTOH ' WORDS 1-
STOP 00E0 FF T SRTl
047 41 LAI #1 00D0 04 INTIL
043 7B IOA 00C8 2D IOS
041 E9 T056 00C4 7A XAB
COLUMN III COLUMN IV
Mach ne Code Instruct on Code Machine Code Instruct on Code
command) language) command) language)
00C2 76 LBA 0114 7A XAB
00E1 61 AISK #1 010A 73 OX
00F0 CA T IBU 0125 70 SOS
00D8 OA SRT 3 EOB #2 0132 7A XAB
00CC 5C X 0139 41 LAI #l
00C6 7A XAB 013C 7E A
00E3 00 NOP 011E 5C X
00D1 71 ROS 012F 49 LAI #9
00E8 7A XAB 0117 74 XAS
00D4 03 INTOH 010B 07 G02 SAG
00CA 3D TL LTOF 0105 50 L
00E5 FF 0122 77 COM
00F2 3B TL LTON 0131 7B IOA
00F9 FF 0138 6F AISK #F
00FC 03 SRT 2 INTOH 01lC DB T G05
00DE C3 T SRT 2 010E 27 RB 4
00EF 7A XAB 0127 00 NOP
00D7 04 INTIL 0113 3C TL SRTl
00CB 2D IOS 0109 FF
00C5 76 LBA 0124 00 G05 NOP
00E2 61 AISK #1 0112 00 NOP
00F1 3E TLSYST 0129 3C TL SRTl
00DC OE EOB#6 0134 FF SAG
00CE 5C X 012D 50 L
00E7 7A XAB 0136 79 XAX
00D3 07 SAG 013B 00 NOP
00C9 71 ROS 011D 00 NOP
00E4 7A XAB 012E OA EOB #2
00D2 03 INTOH 0137 50 L
00E9 39 TL OFLT 011B OA EOB #2
00F4 FF 010D 7A XAB
0ODA 3A TL ONLT 0126 73 0X
00ED FF 0133 70 SOS
00F6 4F OFNR LAI #F 0119 7A XAB
00FB 00 NOP 012C OD EOB #5
00DD 79 XAX 0116 20 S8
00EE OA EOB#2 012B OD EOB #5
87
11787'~Z
TABLE I (cont.)
COLUMN III COLUMN IV
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address, (assembly
command) language) command) language)
00F7 50 L 0115 F4 T G02
00DB OA EOB #2 012A 4F NRl LAI #F
00CD 7A XAB 0140 5C ONLT X
00E6 73 OX 0160 OE EOB #6
00F3 70 SOS 0150 76 LBA
00D9 7A XAB 0148 2B SKBF #4
0OEC OD EOB #5 0144 3A TL NRON
00D6 24 RB 1 0142 E5
00EB OD EOB #5 0161 07 SAG
00D5 3D TL G03 0170 50 L
00EA CE 0158 79 XAX
00F5 00 IBU NOP 014C 40 LAI #0
00FA 00 NOP 0146 74 XAS
00FD 13 LB #3 0163 OE EOB #6
00FE 00 NOP 0151 50 L
00FF 71 ROS 0168 OE EOB #6
0ODF 03 INTOH 0154 7A XAB
00CF 38 TL LOFl 014A 73 OX
00C3 38 TL LONl 00Cl FF
0100 5C LTON X 0165 70 SOS
0120 OA EOB #2 0172 7A XAB
0110 76 LBA 0179 41 LAI #l
0108 2B SKBF #4 017C 7E A
0104 3B TL ONNR 015E 5C X
0102 E5 016F 49 LAI #9
0121 07 SAG 0157 74 XAS
0130 50 L 014B 07 G022 SAG
0118 79 XAX 0145 50 L
010C 40 LAI #0 0162 77 COM
0106 74 XAS 0171 7B IOA
0123 OA EOB #2 0178 6F AISK #F
0111 50 L 015C DB T G025
0128 OA EOB #2 014E 27 RB 4
COLUMN V COLUMN VI
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address, (assembly
command) language) command) language)
0167 00 NOP 0134 00 G024 NOP
0153 3C TL SRT2 019A 00 NOP
0149 C3 01AD 3C TL SRT2
0164 00 G025 NOP 0186 C3
0152 00 NOP 01BB 4F NROF LAI #F
0169 3C TL SRT2 019D 00 NOP
0174 C3 01AE 79 XAX
015A 07 NRON SAG 01B7 00 NOP
016D 50 L 019B 00 NOP
0176 79 XAX 018D OE EOB #6
017B 00 NOP 01A6 50 L
015D 00 NOP 0183 OE EOB #6
88
1~78~7Z'~
TABLE I (cont.)
COLUMN V COLUMN VI
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address, tassembly
command) language) command) language)
016E OE EOB #6 0199 7A XAB
0177 50 L 01AC 73 OX
015B OE EOB #6 0196 70 SOS
014D 7A XAB 0lAB 7A XAB
0166 73 OX 0195 00 NOP
0173 70 SOS 01AA 00 NOP
0159 7A XAB 01B5 00 NOP
016C 00 NOP 01BA CE T G023
0156 00 NOP 01C0 10 LONl LBL #10
016B 00 NOP 01E0 09
0155 F4 T G022 01D0 2B SKBF 4
0135 00 NOP 01C8 38 TL NR2
013A 79 XAX 01C4 F6
013D 14 LB #4 01C2 07 SAG
013E 73 OX 01E1 50 L
013F 70 SOS 01F0 79 XAX
011F 10 LBL #10 01D8 14 LB #4
010F 09 01CC 73 OX
0107 AB TM D6 01C6 40 LAI #0
0103 38 TL G015 01E3 74 XAS
0101 DO 01D1 70 SOS
0180 00 OFL NOP 01E8 10 LBL #10
0lA0 00 NOP 0lD4 09
0190 00 NOP 01CA 8D TM D3
0188 5C X 01E5 41 GO 14 LAI #l
0184 OE EOB #6 01F2 7E A
0182 76 LBA 01F9 5C X
0lA1 2B SKBF #4 0lFC 49 LAI #9
01BO 39 TLNROF 01DE 74 XAS
0198 C4 01EF 07 GO 15 SAG
018C 4F LAI#F 01D7 50 L
0186 79 XAX 01CB 77 COM
01A3 OE EOB#6 01C5 7B IOA
0191 40 LAI#0 01E2 6F AISX #F
01A8 74 XAS 01Fl EC T GO 16
0194 50 L 01F8 27 RB 4
018A OE EOB #6 01DC 00 NOP
01A5 7A XAB 01CE 3C GO 17 TL SRT2
01B2 73 OX 01E7 C3
01B9 70 SOS 01D3 Fl GO 16 T GO 17
0lBC 7A XAB 0lC9 07 NR2 SAG
019E 00 NOP 01E4 50 L
01AF 41 LAl #1 01D2 79 XAX
0197 7E A 01E9 14 LB #4
018B 5C X 01F4 73 OX
0185 49 LAI #9 01DA 70 SOS
01A2 74 XAS 01ED 10 LBL #10
01B1 07 GO23 SAG 01F6 09
01B8 50 L 01FB AE TM D8
89
1~787ZZ
TABLE I (cont.)
COLUMN V COLUMN VI
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address, (assembly
command) language) command~ language)
019C 77 COM 01DD DO T GO 15
018E 7B IOA 01EE 00 LOFI NOP
01A7 6F AISK #F 01F7 00 NOP
0193 CB T GO 24 0lDB 00 NOP
0189 27 RB 4 01CD 10 LBL #10
01A4 00 NOP 01E6 09
0192 3C TL SRT2 01F3 2B SKBF 4
0lA9 C3 0lD9 3B TL NRl
0lEC D5
01D6 4F LAI #F
0lEB 00 NOP
01D5 79 XAX
01EA 14 LB #4
COLUM~ VII COLUMN VIII
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address, (assembly
command) language) command) language)
01AC 73 OX 064D 5C INCB
0196 70 SOS 0666 5C
01AB 7A XAB 0673 30 SKBEI #8
0195 00 NOP 0695 48
01AA 00 NOP 066C C8 T A9
01B5 00 NOP 0656 46 All LAI #6
01BA CE T GO 23 066B 5C X
01F5 73 OX 0655 5C INCB
01FA 40 LAI #0 066A 54
01FD 74 XAS 0675 30 SKBEI #C
01FE 70 SOS 067A 4C
01FF 10 LBL #10 067D E9 T All
01DF 09 067E 47 A12 LAI #7
01CF 00 NOP 067F 54 XNSK
01C7 00 NOP 065F Cl T A12
01C3 38 TL GO 14 064F 0C EOB
01Cl DA 0643 C4
0647 3D TL CTAU
03C0 00 NOP
03EO 19 LB #9 07C0 00 D20 NOP
03D0 00 NOP 07E0 00 Dl9 NOP
03C8 30 TLB SET 07D0 00 D18 NOP
03C4 36 07C8 00 D17 NOP
03C2 FF 07C4 00 D16 NOP
07C2 00 D15 NOP
0640 49 SET LAI #9 07E1 00 D14 NOP
0660 74 XAS 07F0 00 D13 NOP
0650 10 LB #0 07D8 00 D12 NOP
0648 48 Al LAI #8 07CC 00 Dll NOP
0644 54 XNSX 07C6 00 D10 NOP
0642 F7 T Al 07E3 00 D 9 NOP
~ 17~'7Z~'~
TABLE I - (Cont.)
COLUMN VII COLUMN VIII
Machine Code Instruction Code Machine Code Instruction Code
(address, (assembly (address, (assembly
command~ language)command) language)
0661 09 EOB #1 07D1 00 D 8 NOP
0670 48 A2 LAI #8 07E8 00 D 7 NOP
0658 54 XNSK 07D4 00 D 6 NOP
064C CF T A2 07CA 00 D 5 NOP
0646 OB EOB #3 07E5 00 D 4 NOP
0663 40 A3 LAI #0 07F2 00 D 3 NOP
0651 5C X 07F9 2F D 2 RT
0668 5C INCB
0654 54
064A 30 SKBEI #4
0665 44
0672 DC T A3
0679 41 A4 LAI #l
067C 5C X
065E 5C INCB
066F 54
0657 30 SKBEI #8
064B 48
0645 C6 T A4
0662 42 A5 LAI #2
0671 5C X
0678 5C INCB
065C 54
064E 30 SKBEI #C
0677 4C
0653 DD T A5
0649 43 A6 LAI #3
0664 54 XNSK
0652 F6 T A6
0669 OD EOB #5
0674 44 A8 LAI #4
065A 5C X
066D 5C INCB
0676 54
067B 30 SKBEI #4
065D 44
066E CB T A8
0677 45 A9 LAI #5
065B 5C X
11787'~Z
In summary, the electronic key telephone systems and the
various component circuits thereof disclosed herein provide a
high degree of reliability owin~ to the distribution of control
on a station-by-station basis and implementation of the control
of each ~tation by means of a stored-program digital micro-
computer with non-volatile program storage. A high degree of
flexibility is also provided by the removable microcomputer,
which may be either replaced by another microcomputer ~ith a
different program, or reprogrammed and re-inserted into the
ætation card circuit 200, in order to implement different or
additional telephone services. The program set forth herein
on pages 21 through 44 will enable the statioD card 200, in
cooperation with the various other system circuits 100-700,
to provide the various telephone services and features listed
hereunder:
1. Handsfree talkback on intercom calls to another station
set: the called party can answer from across his desk or
across the room without touching the telephone. A
volume switch is provided to control the volume of transmissions
received handsfree without affecting the volume setting for
background music.
2. Handsfree origination for both iDternal and Central Office
line calls: by depressing a handsfree key, and then depressing
either the key for the desired internal station, or the key
for a C.O. line, the caller can both dial a ca'l and then con-
duct a handsfree conversation by means of a speakerphone built
into the station æet without ever lifting the handset.
3. ~ulti-line conferencing: the caller can establish a first
C.O. line call, put it on hold, establish a second C.O. line
call, put it on hold, and then depress both C.O. line keys to
establish a conference between the caller and the two outside
parties.
4. Busy 6tation di~play: provided at all station sets to allou
92
11787ZZ
a caller to know what stations, C.O. lines, etc. are busy before
placing a call.
5. ~usic-on-hold: provided to any outside party on a held
C.O. line.
6. Background music: provided to system users at their station
sets, which have an on/off/volume control switch to enable a
user to control the level of background music without affecting
the volume setting for the handsfree feature.
7. Simultaneous call handling: the systems allow two simultan-
eous calls to be on any station set at the same time, one on thehandset and one on the speakerphone, without having to place
either call on hold.
8. Automatic privacy: no action needs to be taken by a station
set user to ensure privacy, but he may release the privacy
feature to allow other station set users to have access to the
called C.O. line.
9. Paging: the systems provide for paging to as many as five
zones, plus all-call paging to all zones, each accessed by
different dial codes. Also, each station set has a paging key
that may be used to access any one of the zones or all-call
directly, without dialing.
10. ~eet-me conference: internal group conferences may be
held by having each conferee depress a conference key on his
station set, which connects each of the conferees' station sets
to every other conferee's station set.
11. I-hold signalling: the visual indicator on the line(s)
which a user has put on hold flashes in a distinctive manner to
identify those lines.
12. Hotlines(s): each station set can reach one or more other
station sets directly, without dialing, by depressing a hotline
key. Access to a hotline-connected station set is guaranteed,
even if it is in use.
93
~i787ZZ
13. Single key intercom operation: an intercom key on the
station set may be depressed to seize the first available
link and register, by means of which a caller may dial an
internal call. Intercom calling may be conducted handsfree by
the caller and the called party, and may continue for unlimited
periods of time without tying up registers. For privacy, or if
in an environment with a high ambient noise level, the caller
or the called party may switch the call to his handset by
picking up his handset.
14. Access to lines that do nGt appear at the telephone: in
a non-square system, or a system having private lines, a user
may dial into a line that does not appear at his station set
by depressing the intercom key and dialing a pre-determined
number.
15. Handsfree mute: by depressing a mute key in the station
set, the user can disable the microphone which is normally
operative in the handsfree mode. Thus, handsfree calls can be
placed in a monitor-only mode. A caller may also establish
privacy to talk to someone at his location without the called
party overhearing. A second depression of the mute key re-
enables the microphone.
16. Do not disturb: by depressing a DND key in the station
set, it is made to appear busy to all internal calls. A sub-
sequent depression of this key restores the station set to
normal availability.
17. Alternate point answering (call steal): an internal call
may be answered from another telephone using the intercom key
to seize a link and register, and then dialing 2 folloued by
the number of the telephone to which the call is directed. If
the call is a handsfree voice call, it may be intercepted
in this manner only within about 30 seconds after it has been
94
~i7~37ZZ
received. If the call is an ICM RING call, it may be inter-
cepted in this manner for as long as the caller is ringing.
The advantages of the present invention, as well as
certain changes and modifications to the disclosed embodiments
thereof, will be readily apparent to those skilled in the art.
It is the applicant's intention to cover all those changes and
modifications which could be made to the embodiments of the
invention herein chosen for the purposes of the disclosure
without departing from the spirit and scope of the invention.
