Tandy Direct Connect 26-2228 Operation 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

a

Class B

computing

device in

accordance with

the specifications

in Subpart J

of Part 15

of FCC

Rules

which

are designed to

provide

reasonable

protection

against such

interferenceina

residential

installation.

However,

there is no

guarantee that

interference

will

not occur

in

a

particular

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 a

different

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

a

Class

B

computing de-

vice, pursuant

to Subpart J

of

Part 15 of FCC

Rules.

Only peripherals (computer

input

output

devices,

terminals,

printers,

etc.)

certified to

comply

with the Class B

limits 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

A

CUSTOMER

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

B

CUSTOMER

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

A

E,

or

„

a

„

pe,ic

"

1 ot 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

a manufacturing

defect is discovered

during the

stated warranty period,

the

defective Equipment

must

be returned

to a Radio Shack

Computer

Center, a Radio Shack retail

store, a participating

Radio

Shack tranchisee

or

a

participating

Radio

Shack dealer

for repair along

with

a copy of the sales document

or lease

agreement. The

original

CUSTOMER'S sole

and exclusive

remedy in

the event ot

a detect 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

B RADIO

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 a Radio

Shack Computer

Center

a

Radio

Shack retail

store,

a participating

Radio Shack

tranchisee

or Radio Shack

dealer along with

the sales

document

C Except

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.

E Some

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

A

V&ll

A

„l

P

J2SY!S

E

P.,.S

EH

l!!i'

R

„

ADI

°

SHACK

SHALL HAVE

N0 LIABILITY

OR RESPONSIBILITY

TO CUSTOMER

OR ANY OTHER

P

™,!?^

E

v

N

^,,,S#

L0SS

W DAMAGE

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

ffi

E

T

D

,yPc»

A„N

^

BUSINESS

0R ANTICIPATORY

PROFITS

OR

CONSEQUENTIAL

DAMAGES

SS^IK? S°H.IHL

USE 0R OPERATION

OF

THE "EQUIPMENT"

OR

"SOFTWARE."

IN NO EVENT SHALL

RADIO

SHACK BE LIABLE

ffi5,J*B5, A

PHOFIT8

'

0R ANY '"DIRECT,

SPECIAL,

OR

CONSEQUENTIAL

DAMAGES ARISING

OUT OF

ANY BREACH

OF THIS

THE

"WptJEHT'

OR

I

"0FTWARE

R!?ING 0UT

°F°R C0NNECTED

WITH

THE SALE

'

LEASE

'

LICENSE

'

USE 0R ANTICIPATED

USE OF

SS^IESISSP'BS

T

n1EuA=l

0V

Ju

L

^

ITA

Il

0N

JL

A

/l

D *arranties,

RADIO

SHACKS LIABILITY

HEREUNDER

FOR

DAMAGES INCURRED

B

In™

T

.°»

MER

uS

R

,.°c

T

„

HERS

SHALL N0T

EXCEED

THE AM0UNT

PAID BY

CUSTOMER FOR

THE PARTICULAR

"EQUIPMENT"

OR

SOFTWARE

INVOLVED.

B RADIO

SHACK shall

not

be

liable

for any

damages

caused by delay in delivering

or furnishing

Equipment

and/or

Software

C

No 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.

D Some

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

a

non-exclusive,

paid-up license

to use the

TANDY Software

on one computer

subject

to

the

followino

provisions:

M

A

Except 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

C CUSTOMER 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

E CUSTOMER is

permitted

to make

additional

copies of

the Software

only for

backup or archival purposes

or it additional

copies are

required

lr

n

J!5,,

,P?

a

II

on

°'

SI

,

^iS

m

E

u,er wi,h

lne

Software,

but

only

to the

extent the Software

allows

a backup copy to

be

made

However for

TRSDOS Software,

CUSTOMER is

permitted to make

a limited 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

a

sale

ol the Equipment

and

KiSRIfAo

nse t0

CUST0MER

"<

t»

a

transaction

whereby

Radio Shack

sells or

conveys such Equipment

to a third 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 a

certain 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 a total

of

3 may

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

a

chance 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

1 Description

of the Modem

Pak

3

2

Installation

5

3 How to use

your Modem Pak

9

4

Sample

log-on session

21

5

Special character codes

23

6 Technical

information

25

7 Programming examples

29

8 Troubleshooting and

maintenance

33

9 Specifications

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).

•

A

cassette

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

a

previously written BASIC program

or data, you'll

need to load the

program into the

Color Computer's

memory from

a cassette 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 a serial interface

printer that is

compatible with your Color Computer. Radio Shack

has

a

line

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

a

carrier 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 a

duplex 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 a

Color

Computer

Insert the

Modem

Pak

into

the

cartridge

slot

on the

right

side of

the

Color

Computer

or into

slot

1,

2 or 3

of

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 4

of the

Multi-Pak

Interface

is

usually

used

for the

disk

controller.)

Modem

Pak

Figure

2

Multi-pak Interface

Installation

Connecting

to a

telephone

Disconnect

your telephone cord from

the wall plate

and connect it to

a

duplex jack

(279-357). To

connect the Modem

Pack to

the

telephone

line, use a

modular-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 a

cassette

recorder

To

transmit a

previously

written

BASIC

program

or data,

you

will need

to

load

the

program

into

the

Color

Computer's

memory

from a cas-

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 a

cassette

recorder.

Connecting a

printer

To

connect

the

Color

Computer

to a

printer, you

will need

a

4-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

a

carriage

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

5

seconds

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

f

SPACE

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 a

black

background).

•

COLOR

COMPUTER MODEM PAK

•

WORD SIZE

M:lbid 7 BITS

PARITY

EVEN

ODD

HM!IJ

STOP

BITS

IMlTli

2 BITS

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 5

K

CASSETTE BUFFER USED... .0000

PRINTER BUFFER SIZE 5

K

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 ke

ys

(

(?)

(T)

@

©

)

and press

( ENTER

)

;

or,

after

pressing

( ENTER

) ,

enter

a

new value with the

up

or down arrow

keys

((£)©)•

1°

display the second

p

age

when

you

are viewing

the first

page,

or vice versa, just press the

(

SPACE

BAR

)

. To enter and leav

e

terminal

mode from the first

page

of the menu, press

( BREAK

)

.

T

o

enter

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 7 bits)

Select the length

of

a data

word here. To change the option,

move

the

cursor to the

app

ropriate 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 th

e

parity from

the options

given by

moving the

cursor and pressing

(

ENTER

)

.

Stop

bits

(1

bit or 2 bits)

Move the cursor and press

(

ENTER

)

to

change the number

of stop

bits; select either 1 or 2.

Auto line feed (ON or OFF)

This

option lets

you

select whether the carriage return will

be

inter-

preted

on the display

as a

carriage return and line

feed

combination

(auto line feed:

ON), or

as a

carriage return only

(auto

line feed: OFF).

To

set th

e auto 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

t

he settin

g,

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 s

etting,

m

ove 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 a

machine

language

program),

select

XMODEM.

To

communicate

with

a

different 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

settin

g,

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 a

program,

set

the tape

recorder

to

play mode,

position the

cursor

to LOAD

and

press

( ENTER

)

.

After the F

I LE

NAME

:

p

rompt

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

a

cassette

I/O

error message, check the computer-cassette

recorder connection

or volume

setting of your cassette recorder, and

try once

again.

To save

a

program

or data stored

in the cassette buffer, set the tape

r

ecorder

to

record

mode. Move the

cursor

to

SAVE and press

(

ENTER

)

. When t

he file name prompt

appears, input the file name

and press

(ENTER)

. The cursor starts blinking

after the program is

completely saved

on cassette.

Notes:

•

A file name

can

be

a

maximum of eight characters

in length.

•

To stop

th

e

loading 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 prin

ters. Sel

ect 600

or

1200 with

the left or right

arrow

keys

and press

( ENTER

)

.

Printer time adjustment

Basically,

the

output timing of

a

printer is set to

B6

at

600 baud, and

5B at

1200

baud. If your printer happens to

have errors,

c

hange

th

is

printer time with

the

up

or down

arrow

keys

after pressing ( ENTER

)

.

For example, if

you

are

using

a

DWP-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

ver

ification). 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

increa

sed

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 a

low-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 a

computer

that has

64K RAM.

With a 16K

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

Chapter 3

Printer

buffer

used

Indicates the amount

of

printer buffer used.

This

lets you

know

how

much buffer space

is

available for

new data.

Note: During

an XMODEM transfer, the print function is not sup-

ported and

so

the

printer buffer is not

used.

This allows the Modem

Pak

to access

the

full buffer

area

for the

cassette

buffer during these

operations.

No matter what size cassette buffer you have allocated,

the

full buffer area

will

be used

in the XMODEM

mode.

Also note

that during

an XMODEM transfer, data is not added to the end of

the buffer,

but

replaces what has already been stored in the buffer.

In the character

mode,

data

is

added to

the end of the buffer.

True lowercase

(ON or OFF)

To display the

true (not color reverse

lowercase letters noted in the

sec-

tion called Uppercase

only) lowercase

letters,

set

this parameter

to

ON.

You can change the

OFF

co

ndition to ON by

pressing

( ENTER

)

. To

change ON

to

OFF, press

(

ENTER

)

once

again.

Note: The true

lowercase mode will

work only with Color

Computers

that

have one of the

following catalog numbers:

26-3

134B,

26-3

136B

or 26-3127B.

ASCII

filter (ON or OFF)

To

transmit

ASCII

codes

only (7-bit

codes

only),

set this to ON. All

characters over

80

hex, and any control

codes except BKSP, HT, LF,

CR and ESC,

are filtered

out.

To transmit

data that contains graphic

codes or special

key

codes, set

this to OFF.

You can change the ON/OFF

condition

by pressing

( ENTER

j

.

Now,

you've

g

ot all the

necessar

y

information

about

the Modem Pak

menu.

Press (BREAK)

or

the

( SPACE

BAR

)

to return to the first

menu, or press

(BREAK )

twice to enter the terminal mode

to

begin

communications.

15

How

to use your Modem Pak

TERMINAL

MODE

By

entering this mode,

you can

use your Color Computer

as an inter-

active

terminal with

a host

system. Most

information services

can

be

contacted via this mode.

ALT

function

keys

While

you

are in

the communications

(terminal) mode,

you

can

use

the

following

ALT

[#]

key

functions. The

number of each ALT key

and its

summarized

description

are listed

at

the bottom of the

first

page of the protocol

menu.

(@)

CD

— Close or open the

cassette buffer for storing

data. Press

(<§)

and

(T)

simultaneously.

The message

CASSETTE

BUFFER

OPEN FOR

RECEIVE indicates the

data you

input (with ECHO ON),

and data from the host

can be

stored in the

cassette buffer. To close the

buffer, press

(@)

©

again. CASSETTE

BUFFER

CLOSED

is

displayed.

In the XMODEM mode, the message RECE I

V

I

NS X

MODEM

F

I LE

appears when

you

pres

s

(@)

and

(T)

.

The

Modem dues not execute

any command except

(

BREAK

)

until the Modem receives

data from

the

transmitter. For

each block of data that is received

or sent,

XMODEM

protocol will display

a dot on

the

screen. When

the com-

munication is over, the

cassette

buffer closes and

the Modem returns

to

the terminal mode automatically.

(@)

(2)

... Send the data in the

cassette buffer. Press

(@)

and

©

simultaneously. The message SENDING

CASSETTE

BUFFER

will appear on the screen and the

data in your

cassette buffer

will

be sent

to

the host

computer auto-

matically. When all

the data has been sent, the

message

TRANSMISSION

COMPLETE

will

appear on the

display.

Note:

Since

you cannot send data

in the

cassette buffer

while the cassette buffer is open, be sure to

close it

as

in-

dicated in the preceding ALT

function

key

description.

16

Chapter 3

(@)

(3)

...

Clear the

cassette

buffer. You

can clear

all data

in the cas-

sette

buffer by

pressing

(@)

and

(D

at the

same

time.

(@)

@

.» View the

cassette

buffer. To

check the

data

in the

cassette

buffer,

press

(@)

and

@

simultaneously.

(@)

©

...Press

(@)

and (jf)

simultaneously to

open the

printer

buffer

and set

the

printer

to

ON.

The message

P R

I NTE

R

FUNCT

I

ON ON

will

appear

and you can

make

a

hard

copy

of

the data displayed

on the

screen (the data

transmit-

ted

with

ECHO:OFF

cannot be

printed).

To close the

printer

buffer, press

(@)

©

again.

The message

PR I NTER

FUNCT

ION

OFF

tells you that

the

printer

buffer

is

closed.

Note:

The ALT

function keys 3

(CLEAR) and 4

(VIEW) are

availa-

ble from the

main menu, as

well

as

in

terminal mode.

Both of these

keys will

operate the

same in either mode.

The

ALT function key 5

(PRINT)

is also available

from the

main menu, but

its function,

when

selected from

the main menu, is

somewhat

different from

its opera-

tion in

terminal mode. When

it is selected

from the

main menu, the

entire contents

of the cassette

buffer

i

s

printed out.

(This operation

can be

cancelled by

pressing

(

BREAK

)

.)

Loading

BASIC

program/data

files into

the cas-

sette

buffer

Important: The BASIC

programs to be

loaded/stored

in the cassette

buffer of the

Modem Pak

must be

in ASCII

format.

Use

CSAVE filename

?

A

to

store

on tape.

1.

Power-up the

system,

making

sure the cassette

recorder

is

proper-

ly

connected

to

the

Color

Computer.

Push the

PLAY

button

down

until it locks.

2.

Input

EXEC

&HC000 or

EXEC 49152 and

press

( ENTER

]

.

The first

page

of the

protocol

menu

is displayed

on the

screen.

If

y

ou would like to

adjust

the cassette

buffer

size, press

the

(SPACE BAR

)

to

display

the

second page

of

the protocol

menu.

17

How

to use

your Modem Pak

Then

move the

cursor

to the

fourth

lin

e of the menu, CASSETTE

BUf-FbK SIZE,

and

press

(

ENTER

)

. After changing

the

buffer

size

with the

up or

down

a

rrow

keys,

return

to

the

first

page by

pressing

the

( SPACE

BAR

)

or

( BREAK

)

.

3.

Move

the cursor

to

the eighth

line

of

the menu,

CASSETTE

BUFFER

..

LOAD

SAVE,

with

the down

arrow key.

While

the cur-

sor

is on the

word LOAD

,

press

(

ENTER

)

.

4.

The

FIL

ENAME

:

prompt

appears.

Input the file

name

and press

(

ENTER"]

.

5.

The

tape recorder

starts

and

the program

is loaded

to the

cassette

buf

fer. To

stop the

loading

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.

6.

To

check

the

data

written

to

the

cassette

buffer,

press

(@)

®

simultaneously.

Storing

BASIC

program/data

files

into the

cas-

sette buffer

1. Before

communication

can take place,

you need

to enter

terminal

mode. Open the

cassette buffer

with the

(@)

(T)

keys

as described

under the heading

ALT

function keys.

2. Use

(@)

@

to check

the

cassette buffer

or

(@)

(3)

to clear

it,

if necessary.

3.

Dial the host's

telephone

number. When the

phone

is

answered,

you hear a high-pitched

tone. Press

the CONNECT

switch

(to

the

ON position)

and gently

hang

up

the phone.

4. As long

as

the

cassette

buffer is open,

all the data

received from

the host will

be stored in

the

buffer. While the

ECHO

mode is ON,

the

data from your own

keyboard

can also

be stored

in the

buffer.

5. Be sure

to close the

buffer after

storing data

by pressing

(@)

©

once

again.

18

Chapter

3

Saving

BASIC

program/data

files

stored

in

the

cassette

buffer

1.

Insert

a

blank

cassette into the

cassette

recorder.

Press the

record-

er's

PLAY and RECORD

buttons at the

same time

until they

lock.

2. If

you ar

e

in terminal

mode, return

to the

protocol menu

by

pressing

(BREAK) .

3. Move

the cursor

to

the

word SAVE

on the

eighth line

of the

menu,

CASSETTE BUFFER.

.

LOAD

SAVE,

with the

down

and right

arrow keys,

and press

(

ENTER

)

.

4.

The

FILE

NAME

:

prompt

appears.

Input the file

name

and press

(

ENTER

)

.

Note:

BASIC

programs are

stored in

ASCII

format.

Transmitting

BASIC

program/data

files

stored in

the

cassette

buffer

1. Load

a

file

from the

cassette

recorder

as described

on

page 17.

Check

to be sure

the

cassette buffer is

closed.

2.

Set up for

communication

as described

in

step 3

at

lower

section

on the previous

page.

3.

Press

(@)

@

simultaneously. The file will

be sent

to

the host

computer

automatically. If the ECHO

mode is ON and

you are

in character

protocol,

you

will

see the file being displayed

on the

screen

as

it is

being

transmitted.

Attention

OS-9 users

. . .

Version 02.00.00 or

greater

of OS-9

contains the Ml

and M2 drivers.

These drivers

can

be installed with

the

Config Utility.

The Ml driver

requires

that

the

Modem

Pak be inserted

into slot

1 of the Multi-Pak

Interface

because

it

utilizes

a hardware interrupt.

The M2

driver, on

the other

hand,

can

be used in any

slot except slot

1 because it

uses

a

polled software

interrupt.

(Consult your

OS-9 manual

for complete

details.)

19

Sample

log-on

session 4

Before

establishing

communications,

be sure to match

the communi-

cation

protocols

with

your host.

Originating

a

call

1. Power-up

the

system. Be sure

all peripherals are properly connected.

2. Type

EXEC

&HC0OB

(ENTER)

or

EXEC

49152

(JNTER} to

display

the

protocol menu.

3. When the protocol menu appears,

check the default settings and

make sure that

your settings agree with those of your host. If you

want

to send

the program stored on cassette, load the

program into

the

cassette

buffer in advance

by

using the

CASSETTE

BUFFER ..

LOAD

parameter. After making the necessary prep

arations

at the

protocol menu, enter

terminal mode

by

pressing

(BREAK)

.

4.

Before

placing

a call, you

can open the

cassette

or printer buffer

to store the data

into the

cassette

buffer, or

to

print out the data

by

using the ALT function keys.

5.

Set the ANSWER/ORIGINATE switch to the ORIGINATE po-

sition (the host computer should

be

in ANSWER mode).

6. With the CONNECT switch off (out), dial the telephone

number

of the host computer.

7. When you

hear

the

carrier tone, press in the CONNECT switch

(ON) and hang

up

the phone.

8.

When

the carrier

detect

(CD)

indicator lights, you can

begin com-

municating. If

you

should

decide to change any

of the parameters

on

the protocol

menu

while

this exchange of

information is in

progress, you can

do so

without

in

terrupting

communications.

All

you

need to do is press

(

BREAK

)

to

re-enter the protoc

ol menu.

Make any necessary changes,

and then press

(BREAK)

again to

return to terminal mode.

When communication

is finished,

be

sure

to

sign off. (The sign-off

will depend on the host

computer;

however, BYE or GOODBYE

is commonly used.)

9.

After

signing

off, wait until the carrier detect LED (CD) goes off;

then

press the

CONNECT switch

so that

it returns

to

the

off (out)

position.

21

Sample log-on session

Answering a

call

1.

Set

the

ANSWER/ORIGINATE switch

to

the

ANSWER position.

2. Wait

for the

remote

computer operator to

call you.

3. Upon

receiving the call, press in the

CONNECT

switch

(ON), and

hang up

the phone.

4. When the

carrier

detect

(CD) indicator lights,

begin

data

communi-

cations.

5. When finished

with

the data transfer, press

the CONNECT switch

so that it

returns

to

the

off (out)

position.

22

Special

character codes 5

Screen

control codes

In

general,

you

can use

the

Color Computer

keyboard

as

usual.

However,

while you

are

using the DC Modem

Pak

to

transmit data,

some keys

can

perform

certain operations.

The following table sum-

marizes

the

special

keyboard capabilities

of the Color

Computer when

used with the Modem

Pak.

(CLEAR)

+

(BREAK)

...

function as

ESC

Hex Value

Keyboard Entry

Operation

08

09

0A

0C

1B41

1B42
1B43

1B44
1B48

1B4B

1B4A
1B6A

1B59

xy

©

or

( CLEAR

)

©

@or

(

CLEAR

)

(7)

(7)

or

( CLEAR

) (j)

(J)

or

(CLEAR)

(T)

(CLEAR

)

+

(BREAK)

(AJ

(CLEAR)

+

(

BREAK

)

®

(

CLEAR

)

+

(

BREAK

)

(g

( CLEAR

)

+ (BREAK)

(6)

(CLEAR)

+

(BREAK)

©

(CLEAR)

+ (BREAK)

®

(CLEAR)

+

(BREAK)

@

(

CLEAR

)

+

(

BREAK

)

(T)

(

CLEAR

)

+

(

BREAK

)

(y)

®®

Backspace cursor or erase

character

Horizontal

tab

Move cursor down one

line

Clear

the

whole

page

and move

the cursor to the home

position

Move

cursor

up one

line

Move

cursor down one line

Move cursor one space to the

right

Move cursor one space to the

left

Move

cursor

to

the beginning of

the page (HOME)

Clear data to

end of line

Clear data to end

of

page

Clear

the

whole page and move

the

cursor

to

the home position

'Reposition cursor

to

designated

line

(x) and column

(y)

*

This code

indicates

the

location of the cursor by

specifying in hex-

adecimal

the

x (line) andy (column)

coordinates.

Note, however, that

the

actual values

given to

the computer are x

minus 20 hex and

y

minus

20 hex. For instance, assume that you

assign

"

!

"

to

y

and

"

#

"

to x.

The ASCII

code

for

"!"

is

21

hex and for

"#"

is

23

hex; by

23

Special character

codes

subtracting

20 hex, the values

become 1 and 3

respectively.

There-

fore, the cursor is located in column 1 on line

3.

To

use the

ESC

control

codes, follow these steps:

1. Press and hold

( CLEAR

)

and

add

(BREAK)

to

it.

2. Release

( BREAK

)

first, and then release

( CLEAR

)

.

3.

Press the appropriate alphabetic

key. (These

must be upper

case

or lower case, as

indicated

in the table above.)

Special

characters

Special ASCII

codes

that

are not displayed on the keyboard

(such as

those

used

in

OS-9) can be generated

by

using

(CLEAR)

in

combina-

tion with certain

keys.

(

CLEAR

)

... functions

as

CTRL

Hex Value

OS-9

Character

....

Display Character

Keyboard

„. . .. _.

_

.

(True Lowercase Mode:

Entry

*

'

OFF ON)

Character

on Printer

5B

5D

7B

7D

5C

7E

5E

7C

60

5F

1B

[

]

(

)

\

I

ESC

[CLEAR]

(8j

[

1

o

o

\

o

T

s

space

«—

] escape

I

]

(

}

\

t

i

space

«—

escape

[

1

(

)

\

1

I

none

(CLEAR)

(9)

( CLEAR

)

(

,

)

(CLEAR

J

(J

(CLEAR

)(/]

(

CLEAR

)

(3)

(CLEAR)

(7)

(CLEAR

Hi)

[CLEAR]

(@)

[CLEAR]

(J

[CLEAR

J[

BREAK

Note:

To generate the

@

mark,

you

must

press

(SHIFT) together

with

(@)

,

since

@

is

used for

the

ALT key

functions.

24

Technical

information

6

Description

of

6551

ACIA

The following

information

will help

you to

write a

machine-language

program for

yourself.

The heart of the

Modem

Pak

is the

6551

ACIA

(Asynchronous

Com-

munication

Interface

Adapter).

It has

an

on-chip

baud

rate

generator,

programmable

interrupts

and

status

register

for ease

of

operation,

false

start

bit detection,

and

echo

mode.

This

ACIA board

is

memory

mapped to

addresses

FF6C to

FF6F

(Hex).

The 6551

uses

four

memory

addresses

for

the

following

functions.

Address

Write

Read

Hex

Decimal

FF6C

FF6D

FF6E

FF6F

65388
65389

65390

65391

Transmit

Data

Register

Receiver Data

Register

Soft

Reset

Status

Register

Command

Register

Control

Register

This

table

shows that

only

the

command

and

control

registers

are

bi-

directional.

The soft

reset

operation

clears the

6551

internal

registers,

but

does

not cause

any

data

transfer.

Therefore,

the

data

written is

"don't

care!' A

RES*

from the

bus

will

clear

all

registers

in the 6551,

while a

soft reset

will

disable

interrupts

and the

transmitter,

turn

off

the

echo

mode,

and

clear the

overrun

error flag

only.

The

following

explains the

status,

command,

and

control

registers

and

gives

programming

examples

for

each.

25

Technical

information

Status register

The

status register is

used to indicate

to

the processor the

status

of

various

6551 functions.

STATUS REGISTER

7 6 5 4 3

2

10

STATUS

SET

BY

CLEARED

BY

Parity

Error*

0=No Error

1=Error

Self Clearing**

Framing

Error*

0-No Error

1»Error

Self

Clearing"

Overrun*

0-No Error

1«

Error

Self

Clearing**

Receive

Data

Register

Full

0=Not Full

1-Full

Read

Receive

Data

Register

Transmit

Data

Register

Empty

0-Not Empty

1= Empty

Write Transmit

Data

Register

DCD

0-DCD Low

1=DCD High

Not

Resettable

Reflects

DCD

State

DSR

0-DSRLow

1-DSR High

Not

Resettable

Reflects

DSR

State

IRQ

0-No

Interrupt

1-

Interrupt

Read

Status Register

*NO INTERRUPT

GENERATED FOR THESE

CONDITIONS.

"CLEARED

AUTOMATICALLY AFTER

A READ OF RDR AND

THE NEXT

ERROR

FREE

RECEIPT

OF DATA.

HARDWARE RESET

PROGRAM

RESET

7

6 5

4

3 2 1

— —

1

— — — — — — —

26

Chapter

6

Command register

The

command register is used to control specific transmit/receive

functions.

COMMAND

REGISTER

|7|6|5|4|3|2|TT0l

PARITY CHECK CONTROLS

BIT

OPERATION

7 6

5

Parity

Disabled-No Parity Bit

Qenerated-No Parity Bit

Received

1 Odd Parity

Receiver

and

Transmitter

1 1 Even Parity

Receiver

and

Transmitter

1

1

Mark

Parity Bit Transmitted,

Parity

Check

Disabled

1

1 1

Space

Parity Bit Transmitted,

Parity Check Disabled

NORMAL/ECHO

MODE

FOR

RECEIVER

0=Normal

1=Echo

(Bits 2 and

3

must

be

"0")

DATA TERMINAL

READY

O-Disable

Re

ceiver and All

Interrupts (DTR

high)

1= Enable

Receiver and All

Interrupts

(DTR low)

RECEIVER INTERRUPT ENABLE

0=lflQ Interrupt Enabled from

Bit

3

of

Status

Register

1=iH5 Interrupt Disabled

TRANSMITTER CONTROLS

BIT

TRANSMIT RT5

INTERRUPT LEVEL

TRANSMITTER

3 2

Disabled

High Off

1 Enabled Low

On

1

Disabled Low On

1 1 Disabled Low Transmit

BRK

HARDWARE

RESET

PROGRAM

RESET

7

6 5 4 3 2 1

—

— —

Command

Register Format

27

Technical

information

Control

register

The

control

register

is used

to

select

the

desired

mode

for the

6551.

The

word

length,

number

of stop

bits,

and

clock

controls

are all de-

termined

by

the

control

register.

CONTROL REGISTER

|7|6|5|4|3|2|1|0|

STOP

BITS

0=1

Stop

Bit

1

=

2 Stop

Bits

1 Stop

Bit

if Word

Length

=8

Bits and

Parity*

IV2 Stop

Bits if

Word

Length

=5

Bits

and No

Parity.

•This

allows

for

9-bit

transmission

(8

data

bits

plus

parity).

WORD

LENGTH

BIT

DATA

WORD

LENGTH

6 5

8

1

7

1

6

1

1 5

RECEIVER

CLOCK

SOURCE

0=

External

Receiver Clock

1=Baud

Rate

Generator

BAUD

RATE

GENERATOR

16x

EXTERNAL CLOCK

50 BAUD
75

109.92

13458

150

300"

600

1200
1800

2400

3600
4800

7200

9600

19,200

'

The Modem Pak has a

baud

rate

of 300.

HARDWARE

RESET

PROGRAM

RESET

7 6 5

4 3

2

1

— — —

Control

Register

Format

28

Programming

examples

7

Machine

Language

Desired configuration:

baud

rate

=

300,

word

length

=

7

bits, stop

=

2 bits, parity

=

even

Instructions

Comments

CLRA

To

program

the

Control

Register

ORA

#$80

2 Stop

Bits

ORA

#$20

7-Bit Word

ORA

#$10

Receiver

Clock=Baud

Rate

Gen.

ORA

#$06

300 Baud

Rate

STA

$FF6F

Write to

Control

Register

CLRA

To

program

the

Command

Register

ORA

#$60

Even

Parity

ORA

#$00

MODE=Normal

ORA

#$08

Tx. Int.

Disabled,

RTS

Active

Tx. On

ORA

#$02

IRQ

Int.

Disabled

ORA

#$01

Rx

Enabled and

All Int.

STA

$FF6E

Write to

Command

Register

CKMDM

LDA

To

check the

Modem Status

(DSR)

$FF6E

Load

Command

Byte

ORA #$01

Insure that

DTR Bit is

Active

STA $FF6E

Output to

Command

Register

LDA $FF6D

Read

Status

Register

ANDrt #$40

Check DSR

Status

BNE CKMDM

Not

Ready

BRA

MREADY

Modem Is Ready

(Power-Up)

LDA

To check

the

Carrier Status

(DCD)

$FF6D

Load

Status

Register

ANDA

#$20

Check

DCD Status

BNE CAROFF

Carrier Is

Not

Present

BRA CARON

Carrier Is

Present

29

Programming

examples

Instructions

Comments

TXDT

LDA

To transmit a

data byte

$FF6D

Check

Tx-Register

Status

ANDA #$10

If Empty

or Not

BEQ

TXDT

Not Empty,

Wait Tx

Data

LDA

DATA

Get Data

Byte

from

RAM

STA

$FF6C

Write

to

Data

Register

RXDT

LDA

To

receive

a

data byte

$FF6D Read

Status

Register

TFR

A,B

Save Status

ANDA #$08

Check if

Received

Any Data

BEQ

RXDT

Not

Received Yet

ANDB

#$07

Received, Check

Any

Error

BEQ

RXDATA No

Error, Good

Data

LSRB

Error, Check

Type of

Error

BCS

PARERR

Parity

Error

LSRB

Error, Check Type

of

Error

BCS

FRAERR

Framing

Error

BRA

OVRERR

Overrun

Error

Notes:

1.

These

example

programs are

applicable

when interrupts are

disabled.

2.

To execute

the

above programs,

you

must

have an assembler,

such

as

EDTASM (26-3250)

or

Disk

EDTASM (26-3254).

30

Chapter 7

BASIC

Desired configuration:

baud

rate

=

300,

word length

=

2 bits,

parity

=

even

=

7 bits, stop

Instructions

Comments

10

To

program the

Control

Register

X=182

This

is B6 (HEX),

300 Baud,

7-bit

Word, 2

Stop

Bits

20 POKE

65391.X

Write to

Control

Register

FF6F (HEX)

30

To

program the

Command

Register

Y=107

This is 6B

(HEX),

Even Parity,

Normal

Receive, Trans.

Int.

Disabled, RTS

Active,

IRQ

Disabled,

Receiver

Enabled

40 POKE

65390.Y

Write to

Command

Register

FF6E (HEX)

50

To

check the

Modem Status

A=PEEK(6£

5390)

Get

Current Command

Byte

60

A=A OR

1

OR in

DTR Enable

Bit

65

POKE

65390.A

Output

New Command

Byte

70

B=PEEK(65389)

Read Status

75

B=B

AND

64

Check only

DSR Status

80

IF

B=0

THEN 100

If B=0,

Modem Is Ready

90

PRINT

"MODEM IS NOT

READY"

If B>0,

Modem Is

Not Ready

95

END

100

PRINT "MODEM IS

READY"

110

To check

the

Carrier Status

Z=PEEK(6£

>389)

Read

Status

Register

120

Z=Z

AND 32

Mask

Off All but

DCD Status

130

IF

Z=0

THEN 160 If Z=0,

then

We

Have

Carrier;

Otherwise,

We Do

Not

140

PRINT

"NO CARRIER"

150

END

160

PRINT

"GOT CARRIER!"

31

Programming

examples

Instructions

Comments

200

To transmit a

data

byte

A=PEEK(65389)

FF6D

(HEX)

210 A=A

AND 16

Transmit

Holding

Register

Empty?

220 IF

A=0

THEN 200

Not

Empty

230

POKE

65388,

D

D

Has Data

Byte

300

To

receive a data

byte

A=PEEK(6.

5389)

Read

Status

Register

310 B=A

AND 8

Receive

Register

Full?

320 IF

B=0

THEN 300

No Data

Yet

330

E=A

AND 7

Check for

Errors

340 IF E=0

THEN 400

No

Errors

350

IF E=1

THEN 370

Parity

Error

355

IF E=2

THEN 380

Framing

Error

360

PRINT

"OVERRUN

ERROR!"

Must

Be

Overrun

Error

365

END

370

PRINT

"PARITY

ERROR!"

375

END

380

PRINT

"FRAMING

ERROR!"

390

END

400

D=PEEK(65388)

410

PRINT

"BYTE

RECEIVED

WAS";D

Got

Data

Byte in D

32

Troubleshooting

and

maintenance

8

When

something

goes

wrong

If you have trouble

(garbled data,

intermittent

errors, etc.),

check the

following:

•

The

phone

connection

should be

clean and

noise-free.

•

There should be

no

one talking

on the

telephone

line.

•

The

phone

and

all

extension

phones

should

be

on-hook.

•

The baud rate

should be

300.

Troubleshooting

chart

Symptom

Problem/Solution

Carrier detect

light off

Check

telephone

connections.

Refer to

Installation.

The

ANSWER/ORIGINATE

switch is not

in the

proper

position.

Refer

to

the

Sample

Log-On

Session.

The

modem at the

other end

is not

compatible.

The

modem

should be a

Bell-system

103

or equivalent.

Garbled

display

The

phone

is not

on-hook.

Hang up the

phone.

Communications

protocol may be

set

incorrectly

(baud

rate,

word

length,

parity, stop

bit). Check

and

change,

if

necessary.

Care

and

maintenance

The

most

common cause

of

problems is a bad

telephone

connection.

Noise

on

the line

or

a

weak

signal

can

result in lost

or

invalid data.

Try to

re-dial

the call to

insure

that the

connection

is

free of

noise and

interference.

The

only

maintenance your

Modem

Pak

should

require is a

periodic

check

of the

cartridge

connection to

the

Color

Computer

and the

con-

nection

to

the

telephone line.

When you

experience

problems

during

data

transfer,

always check

these

connections.

If you

continue

to

have

problems,

contact

your nearest

Radio

Shack

Computer

Center.

33

Troubleshooting

and maintenance

Lightning

Your Modem

Pak has built-in

protection circuits

—

that

meet

or ex-

ceed F.C.C.

requirements

—

to

reduce risk

or

damage from

surges in

telephone

line

current.

However, an incident such

as

a

lightning

strike

near, or

directly to, these lines may

cause

an excessive

surge

of voltage

that can

damage the phone device.

Lightning damage

is uncommon,

but

it

can

occur

to

phones

and other

electronic

devices. If

you

are concerned

about

it or live

in an

area with

frequent and/or

severe electrical storms, we suggest that you unplug

your electronic

products during the storms.

34

Specifications

9

Dimensions

Length

6.2"

(157

mm)

Width

4.3"

(108

mm)

Environmentals

Temperature

(Operating)

55°F

—

85°F

(12.8°C

—

29.4°C)

Humidity (Operating)

40%

to

80%

non-condensing

Electrical

performance

specifications

Receive

frequencies

Answer

Mark

1270

Hz

Space

1070

Hz

Originate

Mark

2225

Hz

Space

2025

Hz

Transmit

frequencies

Answer

Mark

2225

Hz

Space

2025

Hz

Originate

Mark

1270

Hz

Space

1070 Hz

Transmit

power

-13

dBm

(Loop

current

at

40 mA)

Receive

sensitivity

-

35

dBm

(Loop

current at

40

mA)

Baud

rate

Tine Df resistance

300

BPS

200

ohm

(Loop

current

at

20

mA)

Current

drain

120

mA

35

Specifications

Cartridge

connect

signals

Pin No.

Signal

Name

Description

1

2
3

4

5

6

7
8
9

10

11

12
13

14

15

16

17

18
19

20

21

22

23
24
25

26

27

28

29
30

31

32

33
34

35
36

37

38

39

40

NC
NC

HALT*

NMI*

RESET*

E

Q

CART*

+5V

DO

D1

D2

D3
D4
D5
D6

D7

R/W*

A0

A1

A2

A3

A4

A5

A6
A7
A8

A9

A10

A11

A12

CTS*

GND
GND

SND

SCS*

A13
A14

A15

SLENB*

Not

Connected

Not Connected

Halt Input to

the CPU

Non-Maskable Interrupt

to the

CPU

Main Reset

and Power-Up

Clear

Signal to the

System

Main CPU

Clock (0.89MHz)

Quadrative Clock Signal

which

leads E

Interrupt Input

for Cartridge

Detection

+5V

Volts

(300

MA)

CPU

Data Bit

CPU

Data Bit 1

CPU Data

Bit 2

CPU

Data Bit 3

CPU Data

Bit 4

CPU Data

Bit 5

CPU

Data

Bit

6

CPU Data

Bit 7

CPU

Read-Write

Signal

CPU

Address

Bit

CPU

Address

Bit

CPU

Address Bil

CPU

Address

Bil

CPU Address

Bit

CPU

Address

Bit

CPU

Address

Bit

CPU Address

Bit

CPU Address

Bit

CPU

Address

Bit

CPU Address

Bit

CPU Address

Bit

CPU Address

Bil

Cartridge

Select

Signal

Signal

Ground

Signal Ground

Sound Input

Spare Select

Signal

CPU

Address

Bit 13

CPU

Address

Bit 14

CPU

Address Bit

15

Input to

Disable the

Select

to

it 1

2

3

it 4

5

it

6
7

it 8

it

9

it 10
it 11

it 12

36

Schematic

diagram

1U

-B-6

HI

—B

|S

*H.

o a

ll

S3

Ht—

6

'HK-HE

IS*

is

-*-VW^

8 eg n

I

I

*

f

*-a>IS

*—

CE>I

n>|

G3>§

E>IS

3 O
O

>

W

O

O

u-

o

«

•2

t

iz

3 O

o

c

<D

°

|

»

O CO

1

1

S 5

37

SERVICE

POLICY

Radio Shack's

nationwide

network of

service

facilities

provides

quick,

conveni-

ent, and reliable

repair

services

for all

TANDY/Radio

Shack

computer

products,

in most

instances.

Warranty,

service

will

be

performed in

accordance

with Radio

Shack's

Limited

Warranty.

Non-warranty

service

will be

provided at

reasonable

parts and labor

costs.

Because

of the

sensitivity

of computer

products,

and the

problems

which

can

result from

improper

servicing,

the

following

limitations

also

apply to

the ser-

vices offered by

Radio Shack:

1

.

If any

of the

warranty

seals

on any

Radio Shack

and

Tandy

computer

prod-

ucts

it sells

are

broken,

Radio

Shack

reserves the

right to

refuse to

service

the

product or to

void

any

remaining

warranty

on the

product.

2.

If any computer

product

purchased

from

Radio Shack

has

been

modified so

that it

is not

within

manufacturer's

specifications,

including,

but not

limited to,

the

installation

of

any

non-Radio

Shack

parts,

components,

or

replacement

boards,

then

Radio

Shack

reserves the

right to

refuse to

service

the

product,

void any

remaining

warranty,

remove

and

replace any

non-Radio

Shack

part

found

in the

product,

and

perform

whatever

modifications

are

necessary to

return the

product to

original

factory

manufacturer's

specifications.

3.

The cost

for the

labor and

parts

required to

return

the computer

product to

original

manufacturer's

specifications

will

be

charged to

the

customer

in

ad-

dition to

the

normal repair

charge.

CUSTOM MANUFACTURED FOR

RADIO SHACK

A Division of Tandy Corporation

U.S.A.: FORT

WORTH, TEXAS 76102

CANADA: BARRIE,

ONTARIO

L4M 4WS

AUSTRALIA

91

Kurrajong Avenue

Mount

Druitt.

NSW

2770

TANDY CORPORATION

BELGIUM

FRANCE

Rue des Pieds

d'Alouette,

39

5140 Naninne (Namur)

Centre Commercial

des

3 Fontaines

B.P. 147

95022 Cergy Pontoise Cedex

U.K.

Bilston

Road

Wednesbury

West

Midlands

WS10 7JN

2A6

Printed

in

Korea

811016020B