Tandy Direct Connect 26-2228 User manual

TANDY
Direct Connect
Modem Pak
OPERATION MANUAL
cat. no. 26-2228

The FCC Wants You to Know
This equipment generates and uses radio frequency energy. If not installed and used
properly, that is in strict accordance with the manufacturers instructions, it may cause
interference to radio and television reception.
It has been type tested and found to comply with the limits for aClass Bcomputing
device in accordance with the specifications in Subpart Jof Part 15 of FCC Rules which
are designed to provide reasonable protection against such interference in aresidential
installation. However, there is no guarantee that interference will not occur in aparticular
installation.
If this equipment does cause interference to radio or television reception, which can
be determined by turning the equipment off and on. the user is encouraged to try to cor-
rect the interference by one or more of the following measures:
•Reorient the receiving antenna
•Relocate the computer with respect to the receiver
•Move the computer away from the receiver
•Plug the computer into adifferent outlet so that computer and receiver are on dif-
ferent branch circuits.
If necessary, you should consult the dealer or an experienced radio television technician
for additional suggestions
Warning
This equipment has been certified to comply with the limits for aClass Bcomputing de-
vice, pursuant to Subpart Jof Part 15 of FCC Rules. Only peripherals (computer input
output devices, terminals, printers, etc.) certified to comply with the Class Blimits may
be attached to this computer. Operation with non-certified peripherals is likely to result in
interference to radio and TV reception.

TERMS AND CONDITIONS OF SALE AND LICENSE OF TANDY COMPUTER EQUIPMENT AND SOFTWARE
PURCHASED FROM RADIO SHACK COMPANY-OWNED COMPUTER CENTERS, RETAIL STORES AND
RADIO SHACK FRANCHISEES OR DEALERS AT THEIR AUTHORIZED LOCATIONS
LIMITED WARRANTY
CUSTOMER OBLIGATIONS
ACUSTOMER assumes lull responsibility that this computer hardware purchased (the "Equipment"), and any copies ol software included
with the Equipment or licensed separately (the "Software") meets the specitications, capacity, capabilities versatility and other
requirements ot CUSTOMER
BCUSTOMER assumes lull responsibility lor the condition and effectiveness of the operating environment in which the Equipment and
Software are to function, and for its installation,
LIMITED WARRANTIES AND CONDITIONS OF SALE
AE,or„a„pe,ic"1ot ninely (90) ca,endar "ays ,rom lne "ale ol me Radio Shack sales document received upon purchase ol the Equipment
RADIO SHACK warrants to the original CUSTOMER that the Equipment and the medium upon which the Software is stored is free from
manufacturing defects This warranty It only applicable to purchases ol Tandy Equipment by the original customer from Radio Shack
company-owned computer centers, retail stores, and Radio Shack franchisees and dealers at their authorized locations The warranty
is void it the Equipment's case or cabinet has been opened, or if the Equipment or Software has been subjected to improper or abnormal
use If amanufacturing defect is discovered during the stated warranty period, the defective Equipment must be returned to a Radio Shack
Computer Center, aRadio Shack retail store, aparticipating Radio Shack tranchisee or aparticipating Radio Shack dealer for repair along
with acopy of the sales document or lease agreement. The original CUSTOMER'S sole and exclusive remedy in the event ot adetect is
limited to the correction of the defect by repair, replacement, or refund of the purchase price, at RADIO SHACKS election and sole
expense. RADIO SHACK has no obligation to replace or repair expendable items
BRADIO SHACK makes no warranty as to the design, capability, capacity, or suitability for use of the Software, except as provided in this
paragraph Software is licensed on an "AS IS" Basis, without warranty The original CUSTOMER'S exclusive remedy in the event of a
Software manufacturing defect, is its repair or replacement within thirty (30) calendar days of the date of the Radio Shack sales document
received upon license of the Software The defective Software shall be returned to aRadio Shack Computer Center aRadio Shack retail
store, aparticipating Radio Shack tranchisee or Radio Shack dealer along with the sales document
CExcept as provided herein no employee, agent, franchisee, dealer or other person is authorized to give any warranties of any nature on
behalf of RADIO SHACK.
D, EXCEPT AS PROVIDED HEREIN, RADIO SNACK MAKES NO EXPRESS WARRANTIES, AND ANY IMPLIED WARRANTY OF
KL^J^T/t^ PURP0SE IS UM,TED IN ITS DURATION TO THE DURATION OF THE WRinEN
LIMIIcP WARRANTIES SET FORTH HEREIN.
ESome states do not allow limitations on how long an implied warranty lasts, so the above limitation(s) may not apply to CUSTOMER
LIMITATION OF LIABILITY
AV&ll A
„l P J2SY!SEP.,.S EHl!!i' R „
ADI°SHACK SHALL HAVE N0 LIABILITY OR RESPONSIBILITY TO CUSTOMER OR ANY OTHER
P
™,!?^E vN^,,,S# L0SS WDAMAGE CAUSED 0R ALLEGED T0 BE CA"SED DIRECTLY OR
mS?6?1™".^".^^^^, ,? SPSSSHE S0 ,LD 'LEASED 'LI«"SED OR FURNISHED BY RADIO SHACK, INCLUDING, BUT NOT
ffiE T
D,yPc»A
„N ^BUSINESS 0R ANTICIPATORY PROFITS OR CONSEQUENTIAL DAMAGES
SS^IK? S°H.IHLUSE 0R OPERATION OF THE "EQUIPMENT" OR "SOFTWARE." IN NO EVENT SHALL RADIO SHACK BE LIABLE
ffi5,J*B5, APHOFIT8'0R ANY '"DIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY BREACH OF THIS
THE"WptJEHT' ORI"0FTWARER!?ING 0UT °F°RC0NNECTED WITH THE SALE 'LEASE'LICENSE 'USE 0R ANTICIPATED USE OF
SS^IESISSP'BS T n1E uA =l
0V
JuL ^ITAIl
0N
JL
A
/lD*arranties, RADIO SHACKS LIABILITY HEREUNDER FOR DAMAGES INCURRED
BIn™T
.°»MERuSR,.°c
T
„
HERS SHALL N0T EXCEED THE AM0UNT PAID BY CUSTOMER FOR THE PARTICULAR "EQUIPMENT" OR
SOFTWARE INVOLVED.
BRADIO SHACK shall not be liable for any damages caused by delay in delivering or furnishing Equipment and/or Software
CNo action arising out of any claimed breach of this Warranty or transactions under this Warranty may be brought more than two (2) years
after the cause of action has accrued or more than four (4) years after the date ot the Radio Shack sales document' for the Equipment or
Software, whichever first occurs.
DSome states do not allow the limitation or exclusion of incidental or consequential damages, so the above iimitation(s) or exclusion(s) mav
not apply to CUSTOMER
SOFTWARE LICENSE
RADIO SHACK grants to CUSTOMER anon-exclusive, paid-up license to use the TANDY Software on one computer subject to the followino
provisions: M
AExcept as otherwise provided in this Software License, applicable copyright laws shall apply to the Software
B. Title to the medium on which the Software is recorded (cassette and/or diskette) or stored (ROM) is transferred to CUSTOMER but not
title to the Software
CCUSTOMER may use Software on one host computer and access that Software through one or more terminals if the Software permits this
function. K
D. CUSTOMER shall not use, make, manufacture, or reproduce copies of Software except for use on one computer and as is specifically
provided in this Software License Customer is expressly prohibited tram disassembling the Software
ECUSTOMER is permitted to make additional copies of the Software only for backup or archival purposes or it additional copies are required
lr
nJ!5,,,P?aIIon °' SI,^iSmEu,er wi,h lne Software, but only to the extent the Software allows abackup copy to be made However for
TRSDOS Software, CUSTOMER is permitted to make alimited number of additional copies for CUSTOMER'S own use
F, CUSTOMER may resell or distribute unmodified copies of the Software provided CUSTOMER has purchased one copy of the Software for
each one sold or distributed The provisions of this Software License shall also be applicable to third parties receiving copies of the
Software tram CUSTOMER.
G. All copyright notices shall be retained on all copies of the Software
APPLICABILITY OF WARRANTY
A. The terms and conditions of this Warranty are applicable as between RADIO SHACK and CUSTOMER to either asale ol the Equipment and
KiSRIfAo nse t0 CUST0MER "< t» atransaction whereby Radio Shack sells or conveys such Equipment to athird party for lease to
LUblUMEH.
B. The limitations of liability and Warranty provisions herein shall inure to the benefit of RADIO SHACK, the author owner and or licensor of
the Software and any manufacturer of the Equipment sold by Radio Shack.
STATE LAW RIGHTS
The warranties granted herein give the original CUSTOMER specific legal rights, and the original CUSTOMER may have other rights which vary
from state to state.

Important Note
Vour Modem Pak has been designed and constructed to conform to federal regulations and can be con-
nected to the phone line as described in this manual.
Please note that each product connected to the telephone line places acertain load on the line. We desig-
nate this as the unit's "Ringer Equivalence Number."
When using more than one product on the line, total all the ringer equivalence numbers. If they total more
than 5, your phone may not ring. In rural areas atotal of 3may impair ringer operation. To be sure, check
with your local telephone company.
The registration number as well as ringer equivalence number appears on the bottom of the unit.
The Modem Pak must not be connected to:
•Coin-operated phones
•Party-line phones
IMPORTANT INFORMATION
It is very unlikely .. . but if your Modem Pak causes problems on the phone line, the telephone company
has the right to temporarily discontinue your service. If this happens, the telephone company will notify
you and give you achance to have the problem corrected. Also, the telephone company has the right
to make changes in their lines and/or equipment. If these changes affect your Modem Pak or require
changes in its connection, the phone company will notify you in writing so you can take the necessary
steps to insure uninterrupted service.
Direct Connect Modem Pak Operation Manual
©1985 Tandy Corporation, Fort Worth, Texas 76102 U.S.A.
All Rights Reserved.
Reproduction or use, without express written permission from Tandy Corporation,
of any portion of this manual is prohibited. While reasonable efforts have been taken
in the preparation of this manual to assure its accuracy, Tandy Corporation assumes
no liability resulting from any errors or omissions in this manual, or from the use
of the information contained herein.
10 987654321

Contents
Introduction 1
1Description of the Modem Pak 3
2Installation 5
3How to use your Modem Pak 9
4Sample log-on session 21
5Special character codes 23
6Technical information 25
7Programming examples 29
8Troubleshooting and maintenance 33
9Specifications 35
10 Schematic diagram 37

Introduction
Tandy's Direct Connect Modem Pak opens the door to the world of
telecommunications. This 300-baud Modem Pak allows you to send
and receive programs, but you can also use it to contact information
services.
The DC Modem Pak is easy to use because it is designed to plug directly
into the cartridge slot on the right side of your Color Computer, or
into the Multi-Pak Interface (26-3124).
Special features include:
•Selectable word size, parity, and stop bit.
•Full- or half-duplex capability.
•True upper- and lowercase capability (only with these Color Com-
puters: 26-3127B, 3134B or 3136B).
•Acassette recorder and printer can be operated without going back
into BASIC mode.
•Special codes can be generated to edit transmit data and to create
OS-9 characters.
To use the Modem Pak, you'll need a:
•Tandy Color Computer with at least 16K of RAM.
•Color TV (such as Radio Shack Cat. No. 16-232).
•Telephone.
•Cassette recorder. To transmit apreviously written BASIC program
or data, you'll need to load the program into the Color Computer's
memory from acassette recorder, such as Tandy's CCR-81 (26-1208)
or CCR-82 (26-1209).
•Serial printer. You can print out received information while host-
to-computer communication is in progress. Use aserial interface
printer that is compatible with your Color Computer. Radio Shack
has aline of Color-Computer-compatible serial printers, from the
Thermal Printer TP-10 (26-1261) to the Daisy Wheel Printer DWP-220
(26-1278).

Description of the Modem Pak 1
(T) Carrier detect indicator. This indicator lights while the Modem Pak
is receiving acarrier tone.
(2) Line ON indicator. This indicator lights when the Modem Pak is
connected to the telephone line and the CONNECT switch is
pressed to the ON position.
(3) CONNECT switch. This switch connects the Modem Pak to the
telephone line. Press this switch to transmit or receive data from
the telephone line.
(4) ANSWER/ORIGINATE switch. Slide this switch to the ANSWER
position to set the Modem Pak to answer mode. Slide it to the
ORIGINATE position to set the Modem Pak to originate mode.
(5) PHONE jack. Connect to aduplex jack using modular-to-modular
cable. For further information, refer to the Installation section of
this manual.
Figure 1

Installation 2
Before connecting:
1. Be sure that all the equipment, including your Color Computer,
is OFF.
2. Check to see that the CONNECT switch on the Modem Pak is
set to the OFF (outward) position.
3. Connect the television to the Color Computer as described in the
Color Computer Operation Manual or Introducing YOUR COLOR
COMPUTER 2.
Connecting the Modem Pak to aColor
Computer
Insert the Modem Pak into the cartridge slot on the right side of the
Color Computer or into slot 1, 2or 3of the Multi-Pak Interface. Set
the selector switch of the Multi-Pak Interface to the slot number in
which the Modem Pak is inserted. (Slot 4of the Multi-Pak Interface
is usually used for the disk controller.)
Modem
Pak
Figure 2
Multi-pak Interface

Installation
Connecting to atelephone
Disconnect your telephone cord from the wall plate and connect it to
aduplex jack (279-357). To connect the Modem Pack to the telephone
line, use amodular-to-modular cable (279-374). Insert one end of the
cable into the PHONE jack on the Modem Pak, and the other end
into the duplex jack as shown in Figure 3.
Notes:
1. With the Modem Pak connected, your phone can only be used for
conversation when the CONNECT switch is off. So, be sure to set
this switch to the off (outward) position when you are not using
the Modem Pak.
2. Do not connect the duplex jack directly to the Modem Pak PHONE
jack. The duplex jack has to be connected to the modular wall out-
let as illustrated.
Figure 3

Chapter 2
Connecting acassette recorder
To transmit apreviously written BASIC program or data, you will need
to load the program into the Color Computer's memory from acas-
sette recorder.
1. Connect the short cable (DIN plug on one end and three plugs
on the other) to the CASSETTE jack on the back of the Color
Computer.
2. The three plugs on the other end of this cable are for connecting
to the recorder. Consult your Color Computer Operation Manual
or Introducing YOUR COLOR COMPUTER 2, and the cassette
recorder owner's manual for instructions on connecting these three
plugs to acassette recorder.
Connecting aprinter
To connect the Color Computer to aprinter, you will need a4-Pin
DIN to 4-Pin DIN cable (26-3020).
1. Connect one end of the cable to the serial I/O connector on the
rear side of the computer.
2. Connect the other end of the cable to the printer.
3. Consult your printer owner's manual for operating instructions.
Note: To avoid losing characters, printers may need an additional time
delay after receiving acarriage return. If you have excessive characters
on your print-outs, see your information/time-sharing service to ob-
tain the proper configurations (see Printer time adjustment on page 13).

How to use your Modem Pak 3
Follow these procedures to power-up your system:
1. Turn the color computer and the television ON. The OK prompt
should appear on the screen. If OK does not appear, press RESET.
2. Once the OK prompt is displayed, type:
XEC &HC000 (ENTER )
or
EXEC 49152 (ENTER)
The copyright information and version number will be displayed. About
5seconds after the copyright screen appears, the first page of the menu
will be displayed (Figure 4). The second page of the menu can be
displayed by pressing the fSPACE BAR )(Figure 5).
Upon power-up, the menu will always show the default settings as il-
lustrated. The default or selected options are shown in reverse color
(green with ablack background).
•COLOR COMPUTER MODEM PAK •
WORD SIZE M:lbid 7BITS
PARITY EVEN ODD HM!IJ
STOP BITS IMlTli 2BITS
AUTO LINE FEED ON gj3
ECHO (DUPLEX) ON ffl
UPPER CASE ONLY ON Hii
PROTOCOL MiMsl XMODEM
CASSETTE BUFFER LOAD SAVE
PRESS [SPACE] FOR NEXT MENU
ALT [#]
111 [2] [3] [4] [5]
RECEIVE SEND CLEAR VIEW PRINT
Figure 4

How to use your Modem Pak
MENU PAGE 2
PRINTER BAUD RATE £23 1200
PRINTER TIME ADJUST 00B6
XMODEM TIME OUT 10 SEC
CASSETTE BUFFER SIZE 5K
CASSETTE BUFFER USED... .0000
PRINTER BUFFER SIZE 5K
PRINTER BUFFER USED 0000
TRUE LOWER CASE OFF
ASCII FILTER OFF
PRESS [SPACE] FOR PREVIOUS MENU
Figure 5
Changing communications settings
To change one of the communications parameters, move the cursor
with the arrow keys ((?) (T) @©)and press (ENTER
)
;or, after
pressing (ENTER ),enter anew value with the up or down arrow keys
((£)©)• 1° display the second page when you are viewing the first
page, or vice versa, just press the (SPACE BAR ).To enter and leave
terminal mode from the first page of the menu, press (BREAK
)
.
Toenter terminal mode from the second page of the menu, press
(BREAK) twice.
10

Chapter 3
*** The first page of the protocol menu ***
Word size (8 bits or 7bits)
Select the length of adata word here. To change the option, move the
cursor to the appropriate position with the left or right arrow keys (@
©)and press (ENTER
)
.Select another parameter by pressing the
down arrow key ((Tj), or press (BREAK
)
to enter terminal mode.
Parity (even, odd or none)
To detect errors in transmit and receive data, select theparity from
the options given by moving the cursor and pressing (ENTER
)
.
Stop bits (1 bit or 2bits)
Move the cursor and press (ENTER
)
to change the number of stop
bits; select either 1or 2.
Auto line feed (ON or OFF)
This option lets you select whether the carriage return will be inter-
preted on the display as acarriage return and line feed combination
(auto line feed: ON), or as acarriage return only (auto line feed: OFF).
To set theauto line feed to on, move the cursor to ON and press
(ENTER
)
.To set it to off, move the cursor to OFF and press
(ENTER
)
•
Echo (ON or OFF)
Your options are either full-duplex (for simultaneous two-way com-
munication) or half-duplex (for one-way communication). To change
the setting, move the cursor with the left or right arrow keys and press
(ENTER
)
.You may find that the data input by another person is
echoed on your screen, but your own input data is not echoed when
this parameter is set to OFF.
11

How to use your Modem Pak
Uppercase only (ON or OFF)
This option allows you to communicate in either uppercase only (ON),
or upper- and lowercase (OFF). To change the setting, move the cur-
sor with the left or right arrow keys and press (ENTER] .Although
the characters do not appear on the display in true upper- and lower-
case (lowercase is displayed in reverse color —see the section True lower-
case for exception), the letters output to the printer are, in fact, upper-
and lowercase letters.
Note: In the upper/lowercase mode, use (CLEAR
)
©to switch be-
tween uppercase only and upper/lowercase.
Protocol (CHAR or XMODEM)
Select CHAR (character code) when transmitting ASCII character code
only. When transmitting data that contains graphic codes or data that
is in binary (such as amachine language program), select XMODEM.
To communicate with adifferent type of computer, use XMODEM
to avoid transmission errors. In XMODEM mode, data is divided into
blocks of 128 bytes and transmitted with the checksum of that data
block. Because of this block format, control characters contained in
data are considered to be part of the data, and are transmitted with
no individual check. Thus, binary data can also be transmitted. The
communications protocol should be 8-bit, no parity with one stop bit.
To change the setting, move the cursor with the left or right arrow keys
and press (ENTER) .
Note: The remote computer system must use the same protocol that
you select.
Cassette buffer (Load or Save)
With this option, you can load a program or data stored on cassette
tape, or save to tape the program already stored in the cassette buffer.
To load aprogram, set thetape recorder to play mode, position the
cursor to LOAD and press (ENTER ).After the FILENAME :prompt
appears on the screen, input the file name and press (ENTER ).The
cursor stops blinking until the program is fully loaded.
12

Chapter 3
If you had acassette I/O error message, check the computer-cassette
recorder connection or volume setting of your cassette recorder, and
try once again.
To save aprogram or data stored in the cassette buffer, set the tape
recorder to record mode. Move the cursor to SAVE and press
(ENTER
)
.When the file name prompt appears, input the file name
and press (ENTER) .The cursor starts blinking after the program is
completely saved on cassette.
Notes:
•Afile name can be amaximum of eight characters in length.
•To stop theloading or saving of data, press and hold
the (BREAK) key. If the loading/saving process doesn't stop, try
pressing the RESET switch on the back of your computer.
*** The second page of the protocol menu ***
Look at the second page of the protocol menu before going into ter-
minal mode. As you may recall, all you need to do is press the
(SPACE BAR~) to display the second page of the menu screen.
Printer baud rate (600 or 1200)
Set the baud rate of your printer to that of the computer. The Color
Computer's default baud rate is set at 600 for line printers. Select 600
or 1200 with the left or right arrow keys and press (ENTER
)
.
Printer time adjustment
Basically, the output timing of aprinter is set to B6 at 600 baud, and
5B at 1200 baud. If your printer happens to have errors, change this
printer time with the up or down arrow keys after pressing (ENTER ).
For example, if you are using aDWP-210 (26-1257), you need to set
the time that is in the range of A7-BB at 600 baud, and in the range
of 50-5A at 1200 baud.
13

How to use your Modem Pak
XMODEM Time Out (10 sec to 60 sec)
Selects the XMODEM time-out counter (time needed to perform the
checksum verification). Press the up or down arrow keys after pres-
sing (ENTER) to match your time-out counter with that of the remote
computer; this allows proper handshaking to occur.
Cassette buffer size
The memory size of the cassette buffer is set to 5K at initialization.
It can be increased or decreased by pressing the up or down arrow keys
after (ENTER) is pressed.
Note: When the cassette buffer is almost full, the message
CASSETTE BUFFER ALMOST FULL will appear on the screen to
alert you to this condition. When this happens, follow the appropri-
ate procedure to stop the remote system from transmitting data. (Refer
to your host computer documentation for details.)
Cassette buffer used
Indicates how much cassette buffer space has been used. This lets you
know the available buffer size left for new data.
Printer buffer size
The memory size of the printer buffer is set to 5K at initialization.
Be sure to set aside enough buffer space, especially when you are us-
ing large files or when printing on alow-speed printer. To change the
buffer size, first press (ENTER) ,then increase or decrease the size with
the up or down arrow keys.
Note: The total buffer size (cassette buffer +printer buffer) can be
up to 28K with acomputer that has 64K RAM. With a16K RAM com-
puter, the total buffer size is limited to 12K. Before transferring your
data file, be sure that there is enough space available for it in the printer
buffer. When using the modem pak with any Tandy printer, the printer
buffer should never overflow unless the printer is off-line when you
attempt to transfer data.
14