Commodore CBM8010 User manual

CBM8010
IEEE 488 COMPATIBLE
MODEM
OPERATOR'S MANUAL
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CBM 8010 MODEM MANUAL
INTRODUCTION
We sincerely appreciate your selection of Commodore's acoustically coupled
originate and answer IEEE 488 compatible 8010 modem. The CBM 8010 is
compatible with the Bell 103 and 113 modems for use in the United States and with
V.21 specifications for use in CCITT countries. In addition to being compatible
with the IEEE 488 interface, it also conforms to the International Electro-technical
Committee (lEC) specifications for programmable instrumentation.
INSPECTION AND INSTALLATION
Your new CBM 8010 was originally shipped in acarefully designed container. When
you remove the unit, inspect the exterior carefully for any signs of shipping damage.
We recommend that shipping materials be retained for inspection by the shipping
carrier in case of shipping damage, or for reshipment should return to Commodore
be necessaiy
.
If there is no apparent shipping damage, malie sure the power is off and connect
the AC adaptor to the CBM 8010 and to asource of AC power (115 VAC -US,
230 VAC -CCITT). Connect the IEEE 488 compatible connector to the 24-pin
connector on the back of the modem.
SWITCHES
OR. OFF. AN The 8010 is designed to function as either an ORiginating or
ANswering acoustically coupled modem. For teleprocessing applications when the
originate mode is desired, the OR. OFF. AN switch should be switched to the OR
position.
For termLaal-to-terminal communications when the answer mode is desired, the
OR. OFF. AN switch should be switched to the AN position.
To turn the 8010 's power off, the OR. OFF. AN switch should be switched to the
OFF position.
FD.TST.HD The CBM 8010 may be operated in either the Full Duplex or Half
Duplex mode. When the half duplex mode is desired (e.g. ,for self testing the
system), the FD.TST.HD switch should be switched to the HD position. The half
duplex mode allows computer/terminal data to be transmitted at the same time
that data is echoed back through the interface for display by the local terminal.
This mode is generally not required on 488 compatible terminals and computers,
b'jt the feature is available for both diagnostic testing as well as local copy
presentation, should it be desired.

In the normal mode of operation, full duplex is selected and the FD. TST.HD
switch should be switched to the FD position. The full duplex mode allows data to
be transmitted simultaneously with the receipt of data from the remote modem.
To activate the self-test mode to verify that the coupler and terminal are
functioning properly, the FD. TST.HD switch should be switched to the TST
position (see "TROUBLESHOOTING").
INDICATORS
TST TST indicates that the CBM8010 is operating in the self-test mode.
CRX CRX indicates that the carrier from the remote modem has been received
and the CBM8010 is ready for teleprocessing.
RCV RCV indicates that data is being received. RCV is on during the receipt of
aSPACE signal and extinguishes upon the receipt of aMARK or when no carrier
is being received.
XMT The XMT indicator serves adual purpose in the CBM 8010 modem. During
the time that the modem is off line, the XMT light is illuminated indicating that the
power is on to the modem. As soon as the modem is activated on line and the CRX
light is illuminated, the XMT mdicator turns off and then follows the MARK/SPACE
condition in the normal convention. That is, the XMT light is on during aSPACE
condition of the local terminal and is off when aMARK is being transmitted.
OPERATION
Adata communications link requires that one station transmit and receive in the
originate mode and the other receive and transmit in the answer mode. If both
stations are in the same mode, adata communications Imk cannot be established
(see SPECIFICATIONS for precise transmit and receive frequencies).
When communicating with atime-share computer, the CBM 8010 should be in the
originate mode as the modem at the computer end will be in the answer mode.
When communicating with another terminal, agreement on the mode of operation
is made prior to data exchange.
ORIGINATE MODE
1. Ensure that the terminal power is on and is ready for remote operation.
2. Switch the CBM 8010 to the ORiginate mode. The XMT indicator will turn on
indicating power is on
.
3. The CBM 8010 should be switched to the Full Duplex mode for most normal
communications. However, in the event that your computer/terminal is
programmed so that it does not display characters locally as they are typed,
the Half Duplex mode allows characters to be echoed back through the

Interface for processing and displayed as received characters. This is
useful to assure that data is accurately processed through the interface.
4. Determine that the remote modem is operating in the ANswer mode. If it is
not, switch the 8010 to the ANswer mode and proceed with instructions
under "ANSWER MODE. "
5. Dial the remote number and wait for ahigh pitched tone.
6. After hearing the answering tone, place handset firmly in the acoustic cups
with the handset cord lying over the word "CORD" on the rear cup. When
the XMT indicator goes out and the CRX indicator turns on, the CBM8010 is
ready for communication.
7. Sign on and proceed with terminal operations.
NOTE: Although the 8010 contains circuitry that minimizes the effects of a
noisy telephone connection, severe line noise may cause transmission problems.
If errors appear, repeat the dial-up procedure to obtain abetter connection.
ANSWER MODE
1. Answer the telephone manually.
2. Ensure that the terminal power is on and is ready for remote operation.
3. Switch the 8010 to the ANswer mode. The coupler will produce ahigh
pitched tone allowing the originating modem at the remote end to accomplish
the handshake necessary for terminal-to-terminal or terminal-to-CPU
communications. The XMT indicator is illuminated showing that power is
on.
4. Place the handset firmly into the acoustic cups with the handset cord lying
over the word "CORD" on the rear cup. When the CRX Indicator turns on,
the XMT indicator goes off and the "handshake" is complete. The
CBM8010 is ready for communication.
5. Sign on and proceed with data exchange.
TERMINATING ACALL
1. Type asign-off command.
2.Switch the power off and remove the handset
.
NOTE :When the power is turned off in the CBM 8010, the special interface used
in the modem will not interfere with normal operation on the 488 bus.

THE CBM8010/PET OPERATION
This is afuncticaial description of the CBM 8010 modem. This modem can be
connected to computers that utilize the fully implemented IEEE 488 interface. The
interface is compatible with the lEC bus system defined in detail by lEC document
66C022. This interface bus is an international standard with a stringently designed
set of interface lines and termination requirements.
The IEEE 488 interface in the 8010 modem complies with this international
specification including all of the terminations of control and data signals. In addition,
the modem has the standard 45 milliamp drive capability required in the standard.
The preselected address of the CBM 8010 is factory set at "5". If it is necessary to
change the address, auser may do so by opening the modem enclosure and changing
the internal jumpers as shown in Figure 1. The address is binary weighted with Al
having avalue of "1" and A5 avalue of "16". This allows the user to program any
of the thirty-one possible addresses for the device. This IEEE address is the same
for both the TALKER and the LISTENER functions of the modem.
Shown
addressed
for device "5"
Figure 1. Location on Board andWeighted Value of Address Bits
Programming the computer to work with the modem is straightforward. All that
is necessary is to address the modem as aTALKER and if acharacter has been
received through the acoustic coupler and decoded in the custom interface, it will
be presented in parallel to the IEEE bus. An example of this operation is shown
in Figure 2.

10 0PEN4,5
22) GET#4,A$:IFST<>0THEN GOTO20
30
Figure 2. Sample of Program to Input Data from the CBM 8010
This programming example shows how amodem may be accessed from the PET to
read an input character. The short program shown operates as follows:
Statement 10 opens afile numbered 4in the PET computer. This file
is further defined in that it is gomg to talk to adevice addressed
number 5. This is all that is required to notify the PET that an
IEEE device exists on the bus and its address is 5.
Included in statement 20 is aread statement to file #4. The GET
command in the PET will try to read acharacter from the IEEE
device specified in the open statement. As aresult the TALK address
is sent to the modem and if acharacter has been received the
character will be returned as the variable A$. However, if there was
no character available (i.e. ,had not been received into the modem)
the modem will not answer or complete the handshake. This will allow
the Commodore PET to time out, providing anon-zero PET status (ST).
The second half of statement 20 is atest to see if the status is a
Lndicatinga character has been received. Therefore, in this statement,
if the status ST is not equal to 0, then the program will return to
statement 20 and issue another read statement. The result is that the
program will hang on this statement until avalid character has been
received. After acharacter has been received, the program will
execute the subsequent statements.
Note that in order to avoid the hang condition, the PET should be
checked for atime out if no character was available. The INPUT
command may also be used to read the input. However, some format
conditions must be adhered to.*
There are other ways to Indicate that acharacter has been received in
the modem but probably the best way is by the use of the service
request line as specified in the IEEE 488 specification. The SRQ line
will be asserted calling for aservice request from the PET controller
when acharacter has been received. The sequence of operation is as
follows:
When avalid character has been received by the modem, aservice
request is asserted by the CBM 8010 interface. The PET controller
then recognizes the request and in turn issues apolling sequence
called serial poll. When the polling controller addresses the modem
(device 5in this case), the modem will return astatus word as
*Afurther defuiition of the IEEE functions or the interface design may be found
in the book, "The PET and the IEEE 488 (GPIB)" published by Osborne-
McGraw Hill.

SRQ 1
r-OE -FE CF -CARRIER DETECT
(CRX)
1
Tt
08 D7 D6 D5 D4 D3 02 01
Figure 3. Format for the Service Request Control Character
shown in Figure 3. This status word indicates the status of the modem
at the time of the serial poll. In particular, bit D7, as called out in the
IEEE 488 specification indicates that this was the device requesting
service (RQS). Therefore, this bit will be a1if the modem was the
device requesting the service from the IEEE bus.
In addition Vthe actual modem status is also returned to the controller
with bit Dl indicating the CF function of the modem; bit D2 advises
that an improper ASCII character was received Indicating either a
BREAK function or receipt of an invalid character; and bit D3
indicates an overflow has occurred and that either the PET has taken
.longer than the allowed 33.3 milliseconds to process acharacter or
the sending device is transmitting at acharacter rate in excess of
30 characters per second. These diagnostic bits should be useful
for control as well as indicating errors in operation. This status
character is available at any time that the service request (SRQ) has
been raised and acharacter is available for input to the PET.
10 0PEN4,5
20 PRINT#4,"N0W IS THE TIME"
Figure 4. Sample of Program to Output Data to the CBM 8010
Outputting to the modem is equally straightforward via the IEEE
bus. In general, the program shown in Figure 4can be used to
transmit data through the modem. The open statement in line 10
specifies that file 4will be TALKING to device 5. Statement 20
outputs the data, defined by the quotation marks, through file 4, thus
causing the message to be transmitted by the modem. The sequence
of operation is that the PET will send aLISTEN address to the
CBM 8010 modem immediately followed by the ASCII characters
NOW IS THE TIME as defined by the quotation marks. The operation
will then be terminated with acarriage return, line feed. *
The transmit and the receive sections of the modem are double buffered allowing
two complete character times for the computer to respond to either an input or the
output of acharacter. Thus, it is possible for most IEEE 488 compatible
controllers to operate through the modem at arate of 30 characters per second
*Afurther definition of the IEEE functions or the interface design may be found in
the book, "The PET and the IEEE 488 (GPIB)" published by Osborne-McGraw Hill.

(or 300 baud) using BASIC language instructions with the programs previously
shown. If it is not possible to dedicate the controller to inputting from the modem,
it is recommended that the service request (SRQ) function be implemented using an
assembly or machine language subroutine.
APPLICATIONS
For PET-to-PET telecommunications, the following
program may be used at each terminal:
5PRINT"THIS PROGRAM FOR PET-
COMMUNICATION" TO-PET
10 D=5:0PEN D.D
20 C$=CHR$(13)
30 GET#D.A$:IF ST<>0 THEN 100
40 A=ASC(A$) AND 127
50 IF A>96 THEN A=A AND 223
60 IF A=34 THEN A=39
70 PRINT"Cl"CHR$(A)"a";
80 IF A$=C$ THEN PRINT ">";
100 B=FRE(0)
110 GET A$:IF A$="" THEN 30
120 A=ASC(A$):IF A>127 THEN A= AAND 31
130 PRINT A$;
140 IF A$=C$ THEN PRINT "Q>
5
"
;
150 PRINT#D,CHR$(A);
160 GOTO 30
170 END
NOTE: Received messages are shown in reverse, i.e.,
dark letters on abright background.
The following procedure is recommended:
1
.
This transmission is quite susceptible to noise
or vibration at the acoustic coupler. Isolate the
modem from any such mechanical shock.
2. Start with both units in Full Duplex and with
modem power off.
3. Load PET-to-PET program.
4. Establish the telephone link. Agree on which
party shall be ORiginate. The other will be
ANswer.
5. Place telephone handset into modem receptacle.
Cord end is in modem away from controls and
indicators.
6. Switch modem power switch to ORiginate or
ANswer as agreed.
7. Type RUN and RETURN key. Check that CRX
indicator is on. The channel is now ready for
use.
The program shown operates as follows:
Line 10 opens afile for logical device number
5, which is^e modem, to set it up for com-
munication. Line 20 introduces the carriage
return character which is printed on the display
as a"prompt" character at the beginning of the
next line and serves as amessage saying "over."
Line 30 checks for input from the other party
and line 110 checks for akeyboard character
to be output to the other party. Lines 40, 50,
and 120 change shifted characters to control
characters. Line 60 reassigns quote character
{") to (').
For communication with ASCI Icompatible systems
such as the Source or Micronet, the following pro-
gram may be used:
5PRINT"THIS PROGRAM TO COMMUNICATE WITH NET"
10 D=5:0PEN D.D
20 GET#D,A$:IF ST<>0 THEN 100
30 A=ASC(A$) AND 127
40 IF A>96 THEN A=A AND 223
50 PRINT CHR$(A);
60 GOTO 20
100 GET A$:IF A$="" THEN 20
110 A=ASC(A$):IF A>127 THEN A=A AND 31
120 PRINTED, CHR$(A) ;:GOTO 20
130 END
The following procedure is recommended:
1. Start with the modem in the Full Duplex mode
and with modem power off.
2. Load network communications program.
3. Establish the telephone link. After acarrier
tone is received from the network, insert hand-
set into the modem receptacle. Cord end is in
modem away from controls and indicators.
Switch modem power switch to ORiginate. The
CRX indicator should go on.
Type RUN and press RETURN key several
times. The channel is now ready for use in
accordance with the network protocol.
6. If acontrol character is required, use ashift
character. If ESCAPE is required, use ashift I.
For program operation notes, see notes on
PET-to-PET program.
4.
5.

TROUBLESHOOTING
If communication cannot be established or transmission is garbled, the following
tests will help to determine at what point the malfunction is occurring.
TEST #1
1. Switch the CBM 8010 to the Half Duplex mode and use the following test
program to verify that the interface to the PET from the CBM 8010 is
functioning properly.
5REM LDS-B
110 0PEN4,5
115 GET#4,A$
120 PRINT"Q"
130 F0RI=1T0255
140 PRINT"0"I
150 PRINT#4,CHR$(I);
160 GET#4,A$
170 IFST=2THEN PRINT" QTIMEOUT ERROR CHECK DEVICE ADDRESS"
180 IFASC(A$)<>ITHEN PRINT"ERROR NUMBER IS ",1
:
CLR :60T01 1
190 NEXTI
200 PRINT "QSEEEHTEST COMPLETE:
210 GOTO130
2. Type RUN, carriage return, on the PET keyboard and note that the PET
video display unit will show an increasing digit from 1to 255 following
which it will display TEST COMPLETE. If this test performs satisfactorily,
the basic interface electronics and control electronics in the CBM 8010 are
working properly with the PET.
TEST #2
3. Switch the CBM 8010 to the TST position on the HD. TST. FD switch and the
OR position of the OR. OFF. AN switch to the ORiginate position. If the
coupler does not produce a high pitched tone, the coupler is defective; if a
tone is present, proceed with TEST #3.
TEST #3 .
4. Obtain atelephone line free from any noise. Dialing asingle digit on the
teleJ|one will obtain aquiet line for about thirty seconds. If alonger period
of tme is necessary, dial atelephone number that can be controlled and
cover the remote mouthpiece to eliminate any noise.
5. Place the handset firmly in the acoustic cups with the handset cord lying
over the word "CORD" on the rear cup.
6. When the CRX indicator turns on, reinitiate the test program entered
earlier. Type RUN, carriage return, and verify that the modem is
operating the same as it had previously operated in the Half Duplex (local)

mode. If the data is garbled, the acoustic coupling portion of the modem
is possibly inoperative. If the test is correct and the number 255 is reached
and TEST COMPLETE is indicated, skip to TEST #4.
7. If the message is garbled or if the CRX indicator did not come on when the
handset was placed in the cups, the carbon granules in the mouthpiece
microphone may be compacted. This problem is likely to occur if
transmission has been underway for several hours without the presence of a
modulated carrier.
8. Tap the handset sharply with your hand or abook. If the carbon granules are
simply compacted, this will unpack them and allow normal operation.
9. Repeat TEST #3. If the message is accurate, proceed with TEST #4. If the
message is garbled or if the CRX indicator did not come on when the handset
was placed in the cups, repeat TEST #3 with adifferent handset or phone.
(Carbon microphones can become defective with age. )If the message is
still garbled or if the CRX indicator again did not come on, the coupler is
probably defective.
TEST #4
10. Leaving the handset in the acoustic cups, switch the 8010 to the OFF
position for approximately five seconds, and then to the ANswer mode.
11. When the CRX indicator turns on, reinitiate the test program by typing RUN,
carriage return. The counter will once again be displayed on the screen and
TEST COMPLETE will be reached. If the message is not accurate, the
coupler is defective. If the message is accurate, the problem probably lies
in the remote modem, the remote terminal or computer, or your communication
protocol is improper.
NOTE: Because the CBM 8010 modem is designed to operate at 300 bits per second
(30 characters per second), it is possible that the user developed program operating
in the PET computer may not be capable of processing data received at arate of
30 characters per second. When operating with The Source, Micronet, or other
timesharing fecilities, it is often the case that data is transmitted from these
sources at 30 characters per second. Should you find that you are dropping
characters or missing entire messages, you should consider examining your
program to verify that it will, in feet, process acharacter within 33.3 milliseconds
or less, in order to receive subsequent characters. The. CBM 8010 is equipped
with a two character buffer so that the user may choose to process more than one
character should it be available at the interface.

PIN CONNECTIONS
Amp -
552791-1
P{n# Signal Lme Signal Definition
1DIOl —~"'
•
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Parallel Data Bit 1
2DI02 Parallel Data Bit 2
3DI03 Parallel Data Bit 3
4DI04 Parallel Data Bit 4
5EOI End of Output/Identify
6DAV Data Available
7NRFD Not Ready for Data
8NDAC Not Data Accepted
9IFC Interface Clear
10 SRQ Service Requested
11 ATN Attention
12 Frame Ground
13 DI05 Parallel Data Bit 5
14 DI06 Parallel Data Bit 6
15 DI07 Parallel Data Bit 7
16 DI08 Parallel Data Bit 8
17 REN Remote Enable
18,19,20 Shield Ground
21,22,23
24
SPECIFICATIONS/IEEE
The CBM 8010 modem conforms to the IEEE 488-1978 specification. This
specification is astandard accepted by the IEEE and lEC for programmable
mstrumentation. ITie functions supplied or supported by this modem are:
AHl (Acceptor Handshake)
SHI (Sender Handshake)
Tl (Talker)
LI (Listener)
SRI (Service Request)
Service request (SRQ) is supported allowing interrogation by aserial poll from
the IEEE 488 controller in the system. An SRQ is initiated by acharacter received
in the modem. The serial poll conforms to the IEEE subcommittee protocol
proposal. The serial poll status returned contains the following information:
carrier detect, overrun error (for baud rate errors) and framing error (for
break indication). This modem is intended for 300 baud or 30 character per
second operation only.
10

SPECIFICATIONS/MODEM
Data Rate 300 baud (30 characters per second -10 bit ASCII compatible)
Compatibility Bell 103 and 113; CCITT V. 21
Transmit Frequencies US -Originate -1070 Hz/Space, 1270 Hz/Mark;
Answer -2025 Hz/Space, 2225 Hz/Mark.
CCITT -Originate -980 Hz/Mark, 1180 Hz/Space;
Answer -1650 HzAlark, 1850 Hz/Space.
Receive Frequencies US -Originate -2025 Hz/Space, 2225 Hz/Mark;
Answer -1070 Hz/Space, 1270 Hz/Mark.
CCITT -Originate -1650 Hz/Mark, 1850 Hz/Space;
Answer -980 Hz/Mark, 1180 Hz/Space.
Frequency Stability Crystal controlled, accurate to iO. 3%
Receiver Sensitivity -50 dBm ON, -53 dBm OFF.
Transmit Level -9 to -16 dBm.
Modulation Frequency Shift Keyed.
Carrier Detect Delay 1.2 seconds ON; 120 milliseconds OFF.
T-erminal Interface Compatible with IEEE 488 and lEC specifications.
Environmental .Ambient operating temperature 10° to 40° C. Relative humidity
10% to 90% (non-condensing).
Power Supplied by 20 VAC/400 milliamp wall mount transformer. Input
115 VAC, 2.5 watts. (A 220 VAC, 50 Hz adaptor is available for CCITT users.)
Dimensions 10 5/8" X43/8" X21/4"
Weight 2lbs. (3.25 lbs. shipping weight including AC adaptor.)
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