Radio Shack Modem 4P User manual

Custom Maiw'aaurfld in USA By RADIO SHAClC ADivlMm ol TANDY CORPORATION

Modem 4P
Operation Manual

Important Note
Before connecting your Modem 4P to me phone lines, notify your local telephone
company of the:
Manufacturer; Radtu Shack
Model. Modem 4P
Lisoc Number: Rjnc
FCC Registration Number: AAO 68U-S861 6-UM-E
Ringer Equivalence Number (REN): 0.7B
TTtS-66 Modmm 4P Ope-cetlon Manual S1903 Tandy Corporation,
Fort Worth, Texas 76102 USA All Right* Reserved
RftprorliintirKi nr urb. without fwpmas written permission from Tandy Corporation,
Of any portion ol this manual is prohibited. While reasonable etforta have been
taker) in the preparation of this manual to assure ns accuracy. Tandy Cwpcailon
asfuriMK no habafty iseurting From any errors or omia*ior>B fn this manual, or from
the use of the information contained herein.

Contents
Introduction >.iii
iDescription ot the Modem 4
H
1
2/Settlng Up the Modem 4P 3
Installing the Modem 4P 3
Connecting the Telephone to the Modem 4P 4
3/Programming the Modem 4P „..,., ,,, 9
4/Troubleshooting and Maintenance 17
^/Specifications 19
Appendix A/How Quickly Does Your Modem Dial? 21
Appendix B/Modem 4P Programming Commands 23
Appendix CTechnical Information 29

Introduction
Congratulations on your purchase of the Modem 4R This modem
has no swilclws ut liyl its arid is entirely controlled by Model 4P
Compiler keyboard entries. Acard edge connector at one end of
the card connects the modem to the computers power circuitry
The other end of the card has two telephone connectors which
let you attach atelephone in parallel with existing telephone
circuitry. Also, at trie back of the card is an RS-232C cable, which
connects to the RS-232C output of your computer. The Modem
flP is fully controllod by Iho RS 232C port and aerial data ia
passed from the computer to the modem
Commands are used to program the Modem 4P via the keyboard.
You can program the Modem for Manual/Originate or Manual;
Answer modes which means that if you are contacting aremote
computer in Manual Originate mode, you will manually dial the
telephone number, and when you are in Manual/Answer mode,
you will manually answer an incoming call. Or, you can program
the Modem for Auto/Originate or Auto/Answer which means that
whftn in Autn/Orkjirwte mode, ihe Modem will automatically dial
the telephone number of aremote computer, and when in Auto/
Answer mode, the Modem will automatically answer an incoming
call.
ii!

Ill ddditivn, Um Modem 4P has these features:
Easy installation
Fully programmable from the keyboard
Auto Dial and Auto Answer capability
This manual will:
Give adescription of the Modem 4P
Snow you how to program the Modern 4P
iV

i/uescnption oi tne Modem 4P
©Power Supply Connector. Connects with the Power Supply
channel located inside of the Model 4R
®RS.232C Cable. Connect this cable to the Model 4P s
adjacent RS-232C Output Channel.
®Modular- to-Tefephone Outlet Jack. Connect one end of a
iiiudulai-tyutt cable to this Jack. Connect the other end of
the modular-type cable to the connector labeled, TO WALL.
Connect the other end to amodular telephone outlet
$Modem-to-Tetepbone Jack. Connect the modular cable from
the telephone to the Jack labeled, TO PHONE.
Note: The TO WALL and TO PHONE Jacks are interchangeable.

jHunifc
Figure 1. Modem 4P

2/Setting Up the Modem 4P
Figure 2. Installing the Modem 4P

1
.
Turn off all power to you rModel 4R
2. Open the panel on the back of the computer, Remove the
rtWlal pl«quw uver Ihw RS-232C uunnecluf using a. VU-inch
socket nut driver.
3. Insert the Modem 4P (components cido down) into the cord
slot.
4. Connect the RS-232C cable to the Model 4P's RS-232 output
channel.
Connecting the Telephone to the Modem 4P
The way you connect your Modem 4P depends on how your
telephone is connected to the wall. The following figures illustrate
these connections.
It your telephone has the older style, four-prong, connection, use
an adapter (279-360) to connect tt to your modem.
II your telephone is wired directly to the wall, contact your
telephone company.

Figure 3. Modular Connector

Figure 4. Wall Connector

Connecting the Modem 4P to Multi-Line
Telephones
You can use your Modem 4P with amulti-line telephone.
However you may need aMutti-LSne Adapter (such as Radio
Shack Catalog Number 43-270/271 ). ahardware modification to
the Modem 4R or both.
If you use aMulti-Line Adapter only, the HOLD Button on an
extension phone cart interfere with communication. To avoid this
problem, have aqualified Radio Shack Service Technician modify
The Modem 4R
For information about other Adapters which may be used, contact
your Radio Shack store.

a/Programming the Modem 4P
The Modem 4P accepts data from the Model 4P Computer,
converts that data into tones and then sends the tones over
telephone lines to another modem. II also accepts tones from
telephone tines and changes those tones into data that your
computer understands, You can program the Modem 4P to Auto
Dial or Auto Answer and change other parameters simply by
using the Programming Commands thai let you communicate
with the Modem.
The following criteria must be met before computer-to-computer
communication can occur.
Both computers must have ihe same communications protocol;
xBaud Rate (0 300)
xWord Length
xParity
xNumber of Stop Bits
See your Computer owners manual to find out how to set
communication protocol.
One Modem must be in the ORIGinate Mode and the other
must be in the ANSwer Mode. Usually, if you call another
computer, you should be in IlieORtGinat© Mode, If you receive
acall, you should be in Ihe ANSwer Mode.

When you use your Modem 4K in Automatic Mode, you don'i
have to dial any numbers or pick up your telephone receiver to
answer acall —your Modem does all that for you. As tong as
you're going to be at your Computer throughout communications,
you can control the Modem —and your telephone —through your
Computer keyboard. This is another easy way to run certain
communications programs such as Videotex.
You can also send or receive data trom another computer while
you're not at your Computer keyboard. Just write aBASIC or
macnine-language program and use the cumnands described in
this manual (See Appendix B) to program your Modem to dial a
number or answer the phone unattended. By programming your
Modem to download daily receipts to another computer at 12:00
midnight, foe example, you'll save time and be able to take
advantage of lower telephone rates.
ABrief Overview of Modem 4F Commands
The Modem 4P is completely programmable using the following
commands:
10

Modem 4P Programming Commands
Command Function
""£ Swilclies modeen 10 trie Answer modi.
Opeis modem for programming.
Stand by to receive artew Abort code,
Cifisrs i>esetsi modem memory.
Clears cyrrerii telephtona winter i-^n memory muhi precede any new
tei^Ohone number
Toggle ".hi. £c ncnJJr. sw ich
PhM Rnbrry or Tone rjiai if.g ffl pps j
log 3ft ta'cec carrer delect swilcr*
.
Transmits {displays} current contantt 4f omfsm memory to dm computer
Toggles the rVanualAjioma'ic sw:cn.
Switcties tr»B modem totte Originate made.
PInserts j llireB-seuurid pause in dialing sequence
QPuts modem into LOCal Tesl Mode.
RRotary dialing (def-aufl value).
SStow Rotary or Tone dialing (10 pps.) (default value)
TTend dig ing |'0 dgits per second I.
XExecutes current program (dials phone number in memory, goes into
Sell-Test mode, waits lor telephone to ring while In Answer mode}.
USE Erase the last ertfa intend whn programm r% dia-mg in»omali<r>
i. .)or Irisen aus?: s-cire when jrc-sramming ttianing mlormaligr.
Tabl« 1
11

Changing Communications Parameters
After you power- up the Model 4P with the Modem 4P instalted
and load the communications software, you can change the
default communications settings. You will be using some of the
commands listed in Table 1- For amore thorough explanation of
these commands, refer to Appendix B.
Tn sftfl thfi current modem setting, use the List Command by
typing®©-
The ecr»n shows:
M0DE=«
TYPE^O
FCD=Y
TEST'N
NUMB=
RATERS
EXlT-14
Upon power-up, the modem will be set in the Manual/Originate
mode, Forced Carrier Dated ON, no specified telephone number,
slow dialingi speed, and communications exit (HHPD- Each
setting can be changed ind'ivi dually or by typing Itie sellings in
one line,
12

The following illustrated the possible settings;
MODE=M
The MODE setting can be either Manual ui Automatic. If you
select the Manual setting, the modem will not Auto Dial or
Auto Answer, lb change from Manual to Automatic type
UXD. To toggle back to Manual mode, type JXD. When you
press ©, the current parameter settings are displayed.
TYPE=0
Using the TYPE setting, you can place the Modem in either
Originate or Answer Mode. When you are calling another
computer, you will need to place the Modem in the Originate
setting. It the MODE option is Aand the TYPE option is 0,
the Modem 4P will Auto Dial the number you have saved in
its memory (See NUMB=).
When you will be receiving acall, you use the Answer option
(A), It the MODE option is Aand the TYPE oplion is A, the
Modern will wait tor the telephone to ring, then answer the
call. If the MODE option is Mand the TYPE option is A, the
Modem will answer the phone as soon as you type X,
To change the TYPE setting to Originate, type dXD. To
change the I'YPE setting to Answer, type (Jllj-
13