Tandy TRS-80 Service Manual

CUSTOM MANUFACTUREDINU.S.A. BV RADIO SHACK, A DIVISION OF TANDV CORPORATION

-----------

TRS-aO

®

-----------

TRS-80~

Reproduction Tandy prohibited. preparation Corporation or

information

Corporation,

omissions

Multiterminal

of assumes

contained

-----------lIadlO

Copyright

or

use,

While

this

in

this

1983

AlI

Rights

without

or

any

reasonable

manual

no

liability

manual,

herein.

Interface

Tandy

Reserved

express

portion

efforts

to

assure

or

lIIaeIi

Service

Corporation

of

resulting

from

----------

written

this

have

its

the

Manual

permission

manual

been

accuracy,

from

use

of

is

taken any

the

in

Tandy

errors

from

the

Multiterminal

Interface

~~~.~~

®

~~~~~_S_e_r_v_i_c_e~M_a_n_u_a~l~

Sec

1/

2/

2.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

3/

3.1

3.2

3.3

3.4

3.5

TABLE

Description

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Installation.

Software

Installation...............................

Setting Connecting Checking Enabling Disabling Model

Theory

of

USART Baud RS-232c Loopback Processor Schematic Component Circuit Circuit Parts

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Requirements......................

Up

Multiple

A

Installation......................

A

Terminal........................

A

II

to

Operation.............................

Circuitry

Rate

Generator

Interface

Circuit

Interface........................

8000198

Layout Trace, Trace,

List.................................

OF

Terminal

Terminal 16

Conversions

..•.......................

..................•........

.......•...•..............•

Component Solder

CONTENTS

TerminaIs..............

To

The

Computer......

Side

Page

10 10

Il

Il 16 16 18 18

21

23

24

25

26

3 3 6 7 7 9

4/

Troubleshooting

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__

No.

2-1 2-2

2-3

3-1

3-2

Description

Multiterminal

Installation.

DIP

Switch

Typical

System

Programming Programming Progralnming Programming Baud

Rate

LIST

Interface

OF

Board

FIGURES

• • • • • • • • • • • • . • • • • • • • • • • • • • • • • • 4

Settings............................

Installation....................

LIST

Parameters Parameters Parameters Parameters

Generator

OF

TABLES

(Page (Page (Page (Page

••••••••••••••••••••••••••••

Page

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of

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No.

5 8

12 13 14 15 17

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1/

General

The

Multiterminal

16/16B

This

capability,

access

This

results

advantage The

Multiterminal

RS-232C

Peripheral The

normal

duplex,

from

50 driven. an

interrupt

retrieved

to

interface

allows

to

the

in

of

a

seriaI

Processor.

mode asynchronous to

9600.

On

the

is

from

Interface

combined

features

a

cost

shared

Interface

interface

of

The reception created

a

memory

with

up

to

contained savings

data

operation

transmission

computer

and buffer.

TRS-SO

Board

up

to

three

with

six

to

or

the

independent

per

base.

Board

the

as

interface

transmission

the

®

(26-6013)

additional

XENIX

in

a

terminal

is

basically

a-bit

defined

with

character

OS operators

single

Z80A

by

a

baud

is

Service

al10ws multitasking

Model

and

a

Model

software

rate

interrupt

of

any

is

stored

Manual

the

terminaIs.

to

have

16/16B.

the

added

three-port

16/16B

is

range

character,

to

Model

full

or

The

Multiterminai

Cage

assembly

Multiterminal

chain, noted

its

in action. positions slot. part as cage

(J7)

If

of

"None".

in

•

the the

Priority

1

2

3

4

5

6

7

8

9

priority the If

is

a

which

Interface

chart

one

of

not board interrupt Physical

Model

Pos.

Interface

is

internaI

Board

position below the

boards

present,

position

cycle,

positioning

16B

is

Description ARCNET

Hard Multiterminal Graphics Video/Keyboard 256K 256K 256K 16

Bit

Board

in

to

preserve

then

is

its

from

Disk

Memory Memory Memory

CPU

is

to

the

must

be

the

listed

the

other

not

critical, priority of

the

bottom

Interface

Board Board Board

Board

mounted

Computer.

in

card

this in

the

board

Interface

in

the

interrupt

cage

must

daisy-chaining

first

boards

i.e.

move

it

position

in

the

(JI)

to

the

Card

Since

be

three

up

is

card

top

priority

the

as

a

not

noted

1

2

3

None None None None None None

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----------lIadlo/haelÏ

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Multiterminal

Interface

TRS-SO

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S_e_r_v_i_c_e_M_a_n_u_a_l_

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Installation

n_a_I_I_n_t_e_r_f_a_c_e_

TRS-SO

~-'

Service

Manual

Included installing PCB

in allows terminaIs used Manual

2.1.

The which higher.

01.03.00.

If necessary

(Catalog

a

If necessary

(Gatalog

by

only

you

version

you

in

and

the

Model

you

to

aIl

for

operating

Software

current

supports

You

already

to

No.

01.03.00

do

not to

No.

the

following

interconnecting

16

interconnect

the

computer

terminaIs.

Requirements

operating

this

must

modify

700-2066)

purchase 700-2052).

have

upgrade

System. the

pages

Radio

instructions

board

the it

Refer

XENIX

using

which

XENIX

the

Shack

so

your

XENIX

are

the

Computer.

as

many

that

to

system

is

TRS-XENIX,

system

Operating

a

software

modifies

Operating

instructions

Multiterminal as

five

a common

the

TRS-XENIX

for

the

offered

to

a

Version

This additiona1 data

system.

by

Version

at

System, update

1.1

System,

01.03.00

Operator's

Radio

least

diskette

or

1.2

it

for Interface

option base

01.03.00

it

Shack

a

is system

will

Core

may

version

be

or

to

be

System

2.2.

The

installation its

modifications

communication The

or rear the

Installation following function

Multiterminal

16B

in

the

cover

top

cover

instructions

of

to

required between

card

is

removed

from

the

Mu1titerminal

ensure

Interface

cage the

proper to

the

it

and

assemb1y.

from

Model

----------IIMIOIhaeIl----------

- 3 -

are

operation, Main

the

Board

the

16.

given

Interface

remote

is

Model

to

allow

Terminal

termina1(s).

installed

It

is

16B

proper

Board,

and

perform

to

al10w

in accessible Case

Assemb1y,

check

a

Model when

out

16

the

or

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Rear View

Manual

Multiterminal

Interface

Board

Rear

View

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CPU

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Multiterminal Interface

Hard Disk

Figure

2-1.

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Upgraded Model 12

Interface

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- 4 -

Board

Installation

Multiterrninal

Interface

~~~.~~®~~~~~_s_e_r_v_i_c_e~M_a_n_u_a_l~_

1. Model

Model

2.

Rear

Cover

16

Turn

allow

the

access unscrewing rear

Insert

on

the

Multiterminal

2-1.

16B

Turn

allow

the

access

mounting Lift

out

down. Remove

the board

the

card

to connector(s) DIP

switch

noted

in connector

Multiterminal

chain. the

must

board

be

Therefore,

in

Removal

computer

to

the

top

computer

to screws on

the

card cage be

to

installed.

on

SI

must

Figure

slot

Interface

and

JI.

JI

if

so

the

two

cover

so

the

at

bot

holding

allow the 2-2.

as

shown

no

that

top

the

cover.

mounting

to

gain

Interface

that

rear the tom

the

cover.

10wer

of

the

brackets

the

Attach

Multiterminal be

set

for

Slide

in

board there The

other

must

Multiterminal

boards

rear

is

Remove

screws.

access.

PCB

as

rear

is

Remove

part

cover

of

plate

from

Multiterminal

the

cable

Interface

the

proper

the

board

Figure

must be

2-1.

be

no

are

facing

the

Lift

noted

facing

the

either

into

The

in

empty

Interface

present.

you

top

up

and

in

you

two

rear

and

cover.

pull

side Interface end(s)

Board.

operation

the

interrupt

slots

to

cover

ta

Figure

ta

of

to

between

board

by

the

The

as

OFF

----------lIadI8

ON

S1-0N

S2-Sa -

InllJ

Figure

J1

Jumpers must

E7-E8

DIP Switch

Inl

OFF

2-2.

J2

be

El0-E11

DIP

- 5 -

J3

in place

E13-E14

Switch

Settings

Ihaell-----------

Multiterminal

Interface

TRS-SC

®

Service

Manual

3.

2.3. The

of terminaIs itself capabilities.

The terminaIs. and DT-I's a TRS-XENIX a and paragraph other

Loosen

to

unit(s) Door Allow provide

Xenix

terminal

console expects

DT-l

proceed

the

Setting

to

Adds25

to

than

the Rear

between

and

tighten

enough

an

Up

system

types

are

connected

the

terminal's

is

automatically TRS-XENIX the

emulation

file

the

console,

directly

2.6). a

DT-l,

screws

Door.

the

cable

internaI

Multiple

is

programmed

--

but

terminaIs

called

to

If,

however,

you

which

Feed

Strain

the

screws

to

the

loop.

TerminaIs

the

to

it

particular

calls

you mode. /etc/ttytype.

just

enabling

have

mount

the

inside

to

system

so

set

them

connect

That

follow

you're

to

let

the

cable(s)

Relief

mounting

of

accommodate

has

that

to the

your

it

characteristics

accommodate

"Adds25"

to

information

connection

terminal

connecting

TRS-XENIX

Strain

from

Bracket

the

to

know

can

be

If

you're

Relief

the

and

Bracket.

bracket

a

wide what

calibrate

two

terminal

set

to is

connecting

instructions

(see

a

know.

Bracket remote the

Rear

to

range kind

and

DT-I

type, the stored

terminal

of

in

A

file

commonly

and

codes

To

let

edit

names.

--

the

just

called

used

TRS-XENIX

/etc/ttytype

At

as

/etc/terrncap

terminaIs.

for

the

NAME

VT

100

VT

52 ADM ADM

ADDS

3a

5

Televideo

that

soon

25

know

point,

as

terminaIs

910

what file

TRS-XENIX

you've

stores

The

following

pre-configured

kind to

enabled

of

include

can

the

characteristics

CODE vt100

vt52 adm3a adm5 tvi910 adds25

terminal

one

work

it.

list

gives

in

/etc/termcap:

you'll

of

the

with

above

your

of

the

be

using,

terminal

aIl

names

---------lIadlelhaell---------

- 6 -

__

M_u_1_t_1._'

t_e_r_m_i_n_a_1_I_n_t_e_r-f-a-c-e_

TRs-aD

®

S_e_r_v_i_c_e_M_a_n_u_a_I

__

2.4. First,

If

it

RS-232

(Cat.

1.

2.

3.

4.

If the RS-232

Connect RS-232

Connect

of

Connect

Channel If

insert

Channel.

the

Multiterminal

Connecting

check

is

cable

No.

the

terminal

cable

which

either

(Cat.

26-1496)

one

jack.

the

null

the A

computer a

assembly.

A

Terminal connector

SeriaI

No. for

end

of

other modem

adapter's

or

B

of

requires

Terminator

connects

Interface

To

Channel 26-4403) each

end adapter.

your

the

Plug

to

terminal. RS-232

of

male

computer.

one

pca,

The

you're

A

and

the

plug

it into

of

Computer

using

or

B,

a

cable

to

(check

any

the

you

will

you

null

to

either

the

unused

three

(see

for

the will modem

the

owner's

SeriaI

connectors

need

Figure

terminal.

need

adapter

terminal's

female

SeriaI

manual),

only

the

2-3)

an

plug

on

2.5. Correct

when XENIX

Type

Response There

will

*

Checking

the

produce

in

disable

will

appear: disable:

disable:

OX=one

For

Installation

installation

following

the

following

ttyOX

be

no

ttyOX

/etc/ttys

of

the

example,

of

commands

noted

command*:

(enter)

response

is

tty

terminaIs,

tty04.

the

Multiterminal

typed

responses.

or

already

not

updated

the

disabled

into

following

either

the

Interface

computer

error

(which

4,

5

or

message

is

OK)

6.

is

ensured

running

----------lIadI8

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- 7 -

Multiterminal

Interface

~~~_~~®~~~~~S_e_r_v_1_·c_e~M_a_n_u_a_l~_

RS-232 Cable

26-4403

Terminal No. 2

T-T~

Alternate Connection

Terminal No. 6

Figure

2-3.

B

Typical

Interface

Terminal No. 5

Installation,

Board

Multiterminal Interface

Terminal No. 4

Multiterminal

PCB

-----------Iadlelllaell----------

- 8 -

__

M_u_l_t_i_t_e_r_m_i_n_a_l_I_n_t_e_r_f_a_c_e_

TRS-SO

®

Service

Manual

Type

Response

2.6. Before

enable

in

cat

Ihconsole 09ttyOl 09tty02 09tty04 09ttyOS

09tty06

(or

"cat

redirection)

the

/etc/ttys

(on

something

/etc/ttys"

Enabling

you a

terminal

enable

following

terminal

A

can

use

command:

>/dev/ttyOX

OX)

similar

were

Terminal

a

terminal,

connected

ttyOI

--

typed

at

<ENTER>

(enter)

it

without

it SeriaI

should

must

look

any

be

enabled.

Channel

the

output

A,

same

type:

To

as

if

To

For

PCB,

Then

enable

any

type:

you're

a

terminal

enable

terminaIs

enable

or

enable

or

enable

ready

connected

tty02

connected

tty04

ttyOS

tty06

to

use

<ENTER>

to

<ENTER>

the

at

the

terminal

SeriaI

Multiterminal

(for

to

(for

to

(for

to

Channel

terminal

JI)

terminal

J2)

terminal

J3)

with

B,

Interface

connected

TRS-XENIX.

type:

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- 9 -

lhaelÏ

----------

Multiterrninal

Interface

~~~_~~®

~~~~~~S~e_r_v~1_'c~e~_M_a_n~u~a_l~_

2.7. If

for the terminal

(Remember:

and the

2.8.

The board

Disabling

you

have

any

connector

proceed

main

Model

provided

to

reason,

type:

disable

thru

disable

There

to

computer

II

A

disconnect

be

the

disconnect

to

can

be

sorne

Terminal

sure

terminal

ttyOl

tty06

is

connector.

16

you

no

tty03)

Conversions

used precautions

a

the

to

terminal first

is

using,

remote

test

disable

the

are

from

and

(for

to

terminal

Multiterminal

taken.

the it.

at

SeriaI

terminal

J3)

main

Again,

the

Channel

connector

computer

check

main

A)

connected

from

Interface

There boards

FCH-FFH. correct

10

normal

The board

70H-7EH II

II/12/16/16B cause TRS-XENIX VDG

of

test

with

boards.

is

that

IC27

operation

was

a

dual

makes

This

this,

on

software

written

for

the

a

Rev

problem

without

addressing

is

a

jumper

the

first

A

or

has

testing

ports only

VDG

board.

of

the

MULTERM

for

ports board.

Rev

an

older

the

jumper

problem

7CH-7FH

on

Rev

has

to

Model

for

B

VDG

video

the

be

A

and

be

installed

This

II. the

Multiterminal

70H-7EH.

If

this

board

mentioned

or

in

early

interpreted

Rev

B

will

OR

not

TRS-XENIX

is

in

if

a

installed,

attempting

above

Model

VDG

from

affect

an

Model

as

boards.

older

on

II

VDG

ports

l

the

Interface

also

to these

uses Model

it

will

run

To

to

older

----------lIadlO

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-

10

-

----------

__

M_u_l_t_i_t_e_r_m_i_n_a_l_I_n_t_e_r_f_a_c_e_

3/

Theory

The

Multiterminal divided Generatori and Model

(5)

II

Of

into

(3)

zao

Interface.

Technical

Operation

Interface

five

parts:

RS-232C

Reference

Interface

See

TRS-SD

Board

(1)

USART

Intel

Manual,

®

can

be

circuitrYi

Specification

SIO

Service

functionally

(2)

(4)

Loopbacki a25lA

Section.

Baud

Manual

Rate

and

3.1 The

Transmitter)

which

seriaI circuit

interface logici designators

3.1.1

The

transmitter CPU, parameter and

specify

transmission

bits,

3.1.2

USART

accomplishes

and

CPU

by

receiver

etc.).

Transmitter

Circuitry

(Universal

is

parallel

can

be

logici

(4)

for

Interface

and

read/write

commands

data.

the

transmission

characteristics

See

a

Medium

aIl

divided

(2)

the

Modem

the

logic

the

operations,

and

Table

Logic

Synchronous

Scale

of

the

data

USARTs

receiver

Configuration

under

into

the

Transmitter

Control

Logic

links

transmitter

mode

3-1

four

are

for

Asynchronous

Integrated

required

CPU

directions.

parts:

logici

logic.

U16,

the

-issues

(asynchronous)

(number

U17,

two

with

data,

commands,

the

programming

the

of

Receiver

Circuit

transformation

(1)

the

(3)

The

schematic

and

U19.

major configuration/

parts

Zao

CPU.

and

reads

for

and

characters,

(MSI)

of

The

USART

CPU

the

Receiver

--

the

The

zao

status

example,

stop

parameters.

The

transmitter stored rate. RDY

which

Transmission Enable RS-232 logic.

in

When

signal.

is

flag signaIs

the

used

controlled

----------lIa«l18

serial1y

transmitter

The

TX

to

request

is

controlled

DSR/DCD

RDY

shifts

signal

another

by and

buffer

either

the

CTS

-

Il

out

the

character

at

the

applied

is

character

CPU

received

empty,

connected internally

or

possibly

by

it

to

from

by

the

an

by

modem

lhaell----------

-

data baud sets

interrupt the the

external

clock the

CPU. TX

control

TX

__

M_u_l_t_i_t_e_r_rn_l._

e

n_a_l_I_n_t_e_r_f_a_c_e_

BAUD

TRS-SO

RATE GENERATOR

®

Service

Manual

ADDRESS

70

71

72

73

CHANNEL

CHANNEL2,LSB BYTE,

COMMAND WORD

7

1

1 1 1 1

~

0

-J

-J W

W

Z Z

z

~

::I:

~

"

t- t-

"

(.)

u

w

-J

..J

w

en en

..

....

0

0, LSB BYTE,

1, LSB BYTE,

6

N

..J

W

Z

z

~

:I:

u

t-

(.)

W

..J

w

CI)

0

~

5

t-

Z

:::>

0

U

t-

Z

w

a:

:::>

:I:

"

t-

"

«

-J

0 0

1

0

~

w

a:

0

t-

w

:::>

..J

~

>

DATA

4

W

:::>

-J

~

>

a:

w

t-

z

:::>

0

"

0

«

0

..J

..

~

....

MSB

3

0

BYTE

1

-J

~

Z

e"

en

t-

:::>

0.

t-

:::>

0

a:

W

t-

z

:::>

0

u

2

1

w

en

-J

:::>

0.

en

:::>

0

:::>

z

t-

z

0

u

1

w

-J

u

>

U

>

t-

:::>

0

0 Z Z

'*'

Ln

w

0.

>

t-

~

t-

~

0

a:

W

t-

:::>

0

u

0

U

m

Il

~

>

a:

~

m

Il

0

Table

----------lIadI8

3-1.

Note 1:

Note 2: Counter Value ReadlWrite in

programming

Bit4,5 =0,

consecutive bytes, LSB first.

Bit

Parameters

lhaelÏ

-

12

-

0-3 =

DON'T

(page

----------

CARE

two

l

of

4)

__

M_u_l_t_l._"

t_e_r_rn_i_n_a_l_I_n_t_e_r_f_a_c_e_

INTERRUPT CONTROLLER

TRS-SD

®

Service

Manual

ADDRESS

74

75

CHANNEL 0 CTC CONTROL/INTERRUPT VECTOR

CHANNEL 1 CTC CONTROL/INTERRUPT VECTOR

76 CHANNEL 2

77

NOT USED

CONTROL WORD:

7

w

-J

en

<t

z

w

1-

..J

0-

en

:>

<t

a:

~

a:

W

0

l-

Il

Z

0

6 5

a:

w

I-

Z

:>

0

U

Il

....

a:

w

~

w

0

l-

0

Il

~

0

DATA

CTC

CONTROL/INTERRUPT VECTOR

W

=>

~

<t

>

a:

W

..J

«

U

CI)

w

a:

0-

U)

Ln

N

Il

....

U)

....

Il

0

w

CJ

0

W

a:

w

e,:,

C'

a:

t::

~

U

0

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U

4

3

w

CI)

a:

Il

a:

....

w

e,:, e,:,

a:

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l-

-J

a:

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LL

W

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Il

0

~

C'

a:

1-

~

"

U

0

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U

Il

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0

1-

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Il

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2

-

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1-0

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us: wO

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1-0

Il

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LL

z

0

l-

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a:

w

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0

CI)

:>

0

=>

z

~

Z

0

u

Il

0

1

0

1

a:

0 1-

u

0

w

a:

0

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0-

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w

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a:

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a:

1-

w

Z

1-

0

~

U

Il

....

Il

0

TIME CONSTANT:

E]

INTERRUPT VECTOR:

1

VECTOR

Table

----------lIadI8/haell----------

3-1.

Programming

-

13

1

DATA

-

~

1 1 1

1

I

1

Parameters

1

O

....

NM

-J-J..J..J

owwww

-zzzz

..Jzzzz

w<t<t<t<t Z::I:::I:::I:::I: Z U U U u· <t

Il

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o

00

Il

........

::I:

U

(page

Il

B

2

y-

u

1-

U

>

en

0

w

1-

a:

W

CI)

z

-

of

L-

0

4)

__

M_u_l_t_i_t_e_r_rn_l._

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n_a_l_I_n_t_e_r_f

a_c_e_

TRS-SO

USART

®

Service

Manual

ADDRESS

78

7A

7C

79

78

7D

CHANNEL0,RECEIVE,

CHANNEL

1, RECEIVE,

2, RECEIVE,

CHANNEL0,USART

CHANNEL

1, USART MODE

CHANNEL2,USART

MODE

7

a:

w

m

:E

::l

z

~

m

~

0

t-

CI)

1

.-

Il

.-

0

c

..J

~

>

z

-

Il

0 0

6 5

M

Il

.-

>

~

a:

~

c c

N

0

Il

0

.-

DATA

TRANSMIT

CHARACTER

MODE/COMMAND/STATUS

/COMMAND/STATUS

MODE/COMMAND/STATUS

4

0

.-

Il

w

>

..J

~

m

a:

~

z

~

w

z

>

w

t-

>

W

Il

a:

Il

~

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2

3

1

J:

t-

CD

C'

Il Il

z

.-

W

0

..J

a:

w

t-

(J

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Ln

a:

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Il Il

J:

0

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0

CI)

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0

.-

1

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ma:

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ot-

ZO

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CI) LI. 0

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(J~

za:

>

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1

CD

Il

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0

Z

>

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Il

0 0 0

0

X

~

Il

.-

X

CD

.-

Il

.-

COMMAND

0

(J

t-

w

CI)

w

a:

Il

.-

Table

3-1.

programming

----------lIadI8/I1aell----------

-

14

a:

0

w

::l

a:

t-

CI)

t-

a: .-

a: a:

w

t-

w

CI)

w

a:

Il

.-

Parameters

-

..J

~~

:E~

a:w Oa: Zm

Il

0.-

w

~

w

(J

w

a:

w

..J

m

~

z

w

Il Il

.-

(page

w

::l

a:

...

a:

t-

c W

.-

3

of

t:

:E

CI)

z

a:

..J

m

~

z

.-

~

t-

w

Il

4)

__

M_u_l_t_i_t_e_r_m_i_n_a_l_I_n_t_e_r_f_a_c_e_

TRS-aO

®

Service

Manual

ADDRESS

79,

78,

7E

70

(con't)

USART

(con't)

1

STATUS

7

W

:J

a:

....

a:

(1)

c

Il

~

6

~

«

w

a:

m

Il

ct

....

ct

c

X

a:

Il

~

LOOPBACK COMMAND

DATA

5

4

a:

0

a: a:

w w

~

«

a:

u-

~

z

:J

a: a:

w

>

0

Il

~

3

a:

0

a: a:

w

>

t:

a:

«

~

Il

~

2

>

....

~

w

x

....

Il

~

Il

1 0

w

:J

a:

....

>

c

a:

x

a:

Il

~

w

~

a:

....

>

c

a:

>

....

Il

~

Table

LOOP8ACK COMMAND

x

7F NOT USED

3-1.

Programming

X

1 1 1 1 1 1

X

Pararneters

X X X

(page

4

of

~

(.)

«

m

0-

0 0

-J

Il

~

4)

----------lIa«l18

Ihaell-----------

-

15

-

Multiterminal

Interface

~~~.~~®

~~~~~~S~e~r~v~1~'c~e~~M~a~n~u~a~1~_

3.1.3 The

receiver

applied

multiplied

detected, receive ROY

signal

interrupt

CPU

to

RX

Enable

3.1.4

The

Modem signaIs signaIs four dedicated

3.2 The

three hard-wired applied of frequency. each different MHz

for 3-2.

signaIs

Baud

independent

each

counter

divided

the

See

Receiver

baud

sixteen

the

buffer.

is

(the

read

Modem

the

flag

Control 05R/DCD, DTR

and

link.

Rate

to

the

counter

The

baud

from

different

Intel

Logic

serially clock

set.

same

character.

and

Control

logic

DTR,

RTS

are

used

Generator

programmable

a

specifie

USART

is fraction

by

the

rate

the

baud

Specification

shifts

(in

this

times).

data

reception

a

character complete

The

RX

interrupt

Logic

handles

CT5,

is

controlled

to

U18

TX

and

fractional

CPU

frequency).

(therefore,

4

MHz

rate

seriaI particular When

RDY

Reception

of

and

control

is

U5ART.

RX

is

programmed

on

frequencies

the

bits

character

signal

as

the

data

the

RTS.

by

the

an

MS!

counters.

The

clocks.

portion

The

the

Z80

8253.

data

RS-232C

each

in,

operation,

"start"

are

is

applied

TX

ROY)

is

controlled

character.

The

state

the

Z80 CPU.

flow

IC

that

counter

The of

individually

can

input

bus.

are

using

bit stored is

stored,

requesting

handshaking

of

data

consists

Each

counter

output

frequency

the

applied

have

clock

The noted

the

it

sequence

in

to

an by

the

These

around

is

into

a

is

2.000

BCD

values

in

is the

the

source

of

is

output

clock

Table

is

RX

the

3.3

The receivers

the

1488

data

purpose

the

1489

signaIs

R5-232C R8-232c +/-12

ICs

and

of

signaIs

ICs

have

Interface which Vdc

U2,

clocks

this

to

Ul,

Interface

convert

levels

U4,

and have capacitor

reduce

U3,

and

resistor

logic

from/to

of

the U7. a

U6.

The

capacitor

is

cross-coupling.

The

terminations

----------Iadlelllaell----------

-

consists

the

R8-232C.

buffers

on

to

increase

receivers

16

-

of

digital

their

to

buffers

The

which

The

for

one

logic

buffers

transmit

output.

the

receivers

the

of

rise

the

and

levels

are

The

time

control

power

the

are

to

of

the

~

.......J

~

1

-

0

:il

QI

CI

=--@

t-3

PI

CT

~

(0

w

tv

.

tJj

PI

~

Q,

:;c

~

cT

(0

G1

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::3

(1)

t;

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cT

0

t;

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-1

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cT

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cT

(0

t;

a

.....

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PI

r-'

H

::3

cT

(0

t;

Hl

~

()

(0

8253

BAUD

(CLOCK

1X

RATE

= 2.000

GENERATOR

MHz)

16X

64X

BAUD

RATE

50

1

75 26,667

OEC

40,000

110 18,182 4706 1,136

HEX

9C40

682B

OEC

2,500

1,667

HEX

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0470

OEC

625

417

284

HEX

0271

01A1

011C

II

150

13,333

3415

833

0341

208

0000

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•

m

300

600

1200

2400

6,667

3,333

1,667

833

4800 417

9600

208

1A06

0005

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0341

01A1

0000

417

208

104

52

26

13

01A1

0000

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0034

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0000

104

52

26

13

0068

a

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0000

0007

7

3

0003

en

(0

t;

<:

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()

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PI

.......

__

M_u_l_t_i_t_e_r_m_i

...

n_a_l_I_n_t_e_r_f

a_c_e_

TRS-SO

®

Service

Manual

supply

"true" the

required

3.4 The

three

seriaI

the DSR/DCD, to switches

3.5 The

control controller

3.5.1

Loopback

loopback

seriaI

USARTs

switch

Processor

processor

voltages.

(-12

data

Address

Volts)

TXD

are

and

the

U9,

signal

and

This

state

Circuit

circuitry channels

and

returned

CTS.

signaIs

UIO,

and

Interface

interface

circuitry, clock

Decoder

or

"false"

if

the

without

the

This

at

U13

circuitry.

biases

signal

provides

modem

to

their

is

done

digital

are

consists

data

the

signal

(+12

external control

switched

Volts)

is

not

a

means

complementary

before

levels.

of

an

transcei~er,

into

state

present.

to

stimulus.

signaIs

the

AlI

on/off

address

either

self-test

DTR

signaIs

RS-232

three together.

decoder,

interrupt

to

create

The

and interface

the

output RTS

RXD,

loopback

of

The

address addressing receiver. Switch

"ADDMATCH" programmable selects

3.5.2

The timing control edge the

3.5.3 The

output

receive

bus.

SWl,

Control

control

signal

of

chip

Data

data

from

CS*.

US.

the

selects

(or

decoder

the

Multiterminal

U21

decodes

manually

which,

logic

Signal

signal

converter

The

Z80

Transceiver

transceiver

U22,

IN).

determines

A7-A4

set,

when

timing

signaIs

to

labeled

When OUT=1,

combined

array),

Circuitry

circuitry

be

acceptable

is

selects

creates

U8,

signal IORQ,

U23.

"OUT".

whether Interface. into

with

consists

U12,

converter

IOR,

Direction the

or

one-of-eight one

of

IOR/IOW

the

and

by

The

direction

individual

of

U15

IOW

the

normal

not

U24 the

line and delays

with

INTEL

is

contro11ed

direction

is

the

Z80

is

a

line

addresses.

outputs

in

U22

chip

receiver

loopback

the respect

farnily

onto

is

to

be

(a

U25,

leading

to

ICs.

by is

the

Z80

an

----------lIadI8

lhaelÎ----------

-

18

-

__

M_u_l_t_i_t_e_r_m_i_n_a_l_I_n_t_e_r_f_a_c_e_

TRS-SO

®

Service

Manual

3.5.4

The existing

(selectable>

single

to

3.5.5

The

from clock applied

version requirements.

Interrupt

interrupt

inform

Clock

clock

the

is

interrupt

bus

used to is

controller

of

the

CPU

Circuitry

circuitry

is

in

the

baud

increased

Controller

format.

each

divided

per

when

two

USART USART

has

places:

rate

in

U20

The are channel.

a

USART

two

parts.

by

2

generator

amplitude

is

to

the

a Z80 TX

RDY,

ORed

needs

create

unbuffered

U18;

to

CTC

RX

together

This service.

First,

a 2

meet

to

match

RDY

to

interrupt

the MHz

version

the

buffered

Z80

and

create

4 clock.

CTC

the BREAK

MHz

is

clock

is

a used

This

----------lIadlelhaelÏ

----------

-

19

-

Multiterminal

Interface

~~~.~~®

~~~~_S~e~r_v~i_c~e~M~a~n~u~a~l~

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lhaelÏ

-

20

-

----------

A'7*

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A.'*

J.-29D----I

A.S*

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A14*

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ACl5*

J.-26D

A12*

J.-2sD----4

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~3-

UI4

S04

ïL-----+-;t-t---12~13--+--+----

'""'-(

'~"""":L

10

5JR~E~A~0~/

__

~~--------;-_,----

WRITEI

14 16

Mtl

7 10RQI

91R~E:!8!!E!TLI

R20

12-

-vA

__

"JV,,-_1--..-:4~MHZ::::::...

18

17

1

-----+-------:::C~16;----

ï

19

r--

~1-{:»-2-

.J_-------___,r_-----_,

A.

v

UI4

Lse4

---+------H-T'---4I--

~f

~r

RI6

1.2K_

.....

---

UI4

LSCl4

3-{:»-4

RI5

~2e

]

---

.....

~S--==-----------------------------

\-12

1-11

+y5V

24

2

~~oe

26

~-01

28

Z7-

02 03

1-

04

2

OS

~

08~~3

01

16-<:

CS

CS,

CS

~

6;m

CLK

Rf

2-D

-3p>

r·

I20

L

1I

1'"

10

9~

t>

~I-f

13

ir:.

l

\ t l <

5 -

IEOHI]

iNT

12-~

lE

1

13

TReCi

23-

U20Tce

7-S

TROI

22-'--

TCI

8-S

1

TRe2

21-~

TC2

9-$

TR63

2<H

5---

~8--s

+5V

- «

f-----,

-r

R21

IOK

1

-----1

1------7

-----602

V 5

V-

V _ 3

V 2 06 IATEI V

V

'----20

-22

JO::

-=

r-23

~}.:

l

)1

7

12

D' 01

03

4

D4~

OS

107

2l-C

ës

19

AD AI

Jm

IATE216-

ft

UJllLW-l--~~==:::~---~--t-=f+_Hrt++t_t=t============:;====;_---

UI

~

LS"

~

L=Ûs-u---------+-t----r-n'

......

-~6

r--4~

UI5

LS32(2)

+5V

~

1

~1

24

ClK0

GATEe

OUT'

U'15

CLK115

OUT113-""'----,

CLK2 OUT

RII

:J.

IDK

9-+-.-----r-Tï

II~

10-t------,

-~-----r-;-~

14-

18-6-----+-+-..,.....,......

2

17

T

+5V

10

~

...J.....!2;!MH~I~

9-

J>

P-I-

UI2

74LS74A

.......

--___.--------_r_I--1

l

c

:>

RI2

560

CI7

l 100

pl

...----

NOTE:

IN

ALL RESISTOR VALUES UNLESS OTHERWISE SPECIFIED.

OHMS

~b~

.l''v-

-----J---4-----+

i:Fu~

~

27 IDe

1

L...-

\ !

26

..14

RXO

DI

02

T)(o

1

+5V~

~S

r-

~~:

~6'osffi~17-Ll-----T-~-t4

v--7

06

-8

07

,

.....

~'K:B.f~~

r-+-+-t--r--13

12

--I~-+--+--r--10

21

2e-ClK

+5V

~23

t=2

278

~

V--

2

~5-

V--

6D5

v--

7

.....-v--

8

-

...

6--t-+-+-

......

+----Ir---

_ _

UI6

RfSb-23

DSR~22--------it----12

-

CID

RD

6TR~24-----=--""--------

fiXf

WR

fXë

RST

TXRDY

RllROY~14

BREAK

~.IUf

1

26

DO"

RXO

1

02

TXO

03 04

ffiP-17--

06 07

UI7

m~23-----+~-~+-----

Ciu':~_

m~22-""'----tr---'2

.......

-----1--12

6-~--_r_-13

6-.J--..I--+---r--

~I---f__+__t_--r__-

6-

........

-+-+--+----,--

L..L-+-+4-+-~-_+-------

'-----12

'-------13

'--------10

......

-------

1L.-

CIlS

OTRp-24------=::!....-~~-----

rm

1

0

21

2"

~~

+~V~\

1'--27 "'---28

'--1

1'--2

1'--5

1'--6

f'--7

8 07

It-<J

21

20

m

WR

m

RST

TXROY

RXRDr

ClK

BREAKH6

...

!

26 4-=

RXO

O' DI 02

TxoL,IQ

03 04 05

ffi~17-

06

UI9

RTi~23---~~-

csu'l:~~#

~p_22-

CID

6iR

ii'6

~

WR

ftë

RST

TXRDY

~~

ClK

BREAK

1.

5

-<Ç)-15

U9

74ALS241

(6/1)

1

19

1

4------3

.....

~-------

~

__

3----4......---+--16

L

19-----+~-

UI

1489(3)

~

U2

1488(4)

-------

1

9

1 8

6----6~4

7

13--,

~-~

LlO

9 1

25.......,

9-......,~------------E-I"'-JJ..

1!5----l1------!

16

E9~

oY.5

..,2!7

1

-_---4......-_-1191'-__16

3 L

'9-----+~-

5:A151

1~

------rVi.--

7 N

L

J 4

1_+-

1 5

l~

-e

=!

pUll

74lS27

4 6J

14Al.S241 '2.2 K

ule

1.

(6/1)

1

---,

1 4

13

4----3~1-------

1 9

......

__f------

~>11_4,.~----6f1.4

N"-v

14

~

_

8V'0

2

12

~E=2----I~13~

+5V

14a';~3)

..

~

141~'4)

It>

5

-12V

l

R2

2.2

.....

------OJI-2

.-.~~~--:-----DJI-3

tl!l

(

!l!.

39

6------+-----,

3---+---+----,

-12V

r

RS

......

-------aJ2-2

-4~~~~~----------C>J2-3

8

te7i

(39~

----,

K

r---C>JI-I.7

-L

.----C>J2-I,7

-

_

GNO

XMIT

RCV

JI-4

RTS

JI-S crs

JI-2e

DTR

JI-6

OSR

JI-I~

TXClK

JI-17

RXCLK

JI-8

CARRIER OETECT

J2-4

J2-S

DATA

GNO

X"IT

DATA

RCVOATA

RTS

CTS

8~10

J2-2'

8----

Lg-<J"=!

25.......,

9-6--------

_

15

~-----lp7

14-'------2

~

3

..

~24----==-~~~-----

25-

9-6------------~

,I~

16-+--_

E12~

oê!

13

~I'

7":~241

(618)

1

19

CI:A

-----~--4~+-----

.....

--t"'---14

L

....

--.----'2

-.

I5

...

~

7

~131

L<:}II=:!

$

t

~

E_l

u_

~I

~13

---~..."

U-1-1

IJ

1

I,

16

4----

J 9

C>'~

rJ'I

......

-+__-----

c

8

ES~

8J

Schematic 8000198, Multiterminal Interface 26-6013

~

20

E3J'\

~E_4-___tl~12:"'1

...

13

+Sv

14.~6('1

3 1

---------..-------0

V

10

6~4

~

8~10

E6

Qoiiii----.....

4

5

~

20

12

-:-:13:;"'1

+SV

--~--+-------t

3

12

14~:(41

-1

:.

_2.2K

~----:------:------D

8

~

(

1

5ge

6

------t----.....,

---+--+------,

3

--..--+---+--

+12V

r-D

......

--",,~

DTR

J2-6

OSR

J2-15

TXCLK

J2-17

RXCLK

J2-8

8:~r~~R

-1•78ND

J3

J3-2

XMIT

J3-3

RCV

J3-4

RTS

J3-5

CTS

J3-21

DTR

J3-6

OSR

J3-15

TXClK

J3-17

RXCLK

J3-8

CARRIER OETECT

DATA

21

1

--------(

~

__

M_u_1_t_i_t_e_r_m_i

U1

R2

-8-

~

R1

~

QOO

o~~

U9

-c::.-

~

...

(

Q~

J1

1

E1(X)E2

~

R13 U10 ° R12

E7~9

U16

..

n_a_l_I_n_t_e_r_f_a_c_e_

U2

~

00

~

E10

~

a:o

E11

E12

U17

U3

-<:::J-

R11

co

0 J2 U4 0> 0

1

r0

00Q)L....-

d

0>

R5

~O

1

'"

~

TRS-SO

------If

E3 R22

Œ)E4

~

Ou

<=J-

-c:::J-

~

{fi?

U11

U18

_1

---

R6

---(

®

U5

U12 u

E13a:o

'<t

E14

[)

Service

U6

R14

~

-e::.r-

R7

~

....

1 < (

E

15

~

U13

U19

G J3

~

000

-<:::J-

R8

~

1

-<:::J-

U14

L{)

[)

E5(X)E6

R9

Manua1

U7

<J

0.,

0

0R23

~

051,,-

R16~16

R15

~

U20

1

__

ua

0

U15

...JI

01

~"

~

(J

L

11F 81

1 <

TANDY CORP. MADE

IN

U21

U.S.A.

@1983

Component

<

C31

-c=J-

Layout,

U22

0100..-

+

-c=J:

80

Mu1titerminal

1

--<Q

+

C32

-c:::r R19

U23

U24

co

C\l

U

Interface

R20

--c::::J-

< Q

0>

C\l

U

Board

0

1

U25

C33+-c=J-

26-6013

0

Ct)

ü

0

~

c::::::=>

C26

R21

--c::::J-

U26

--.J

REV

2

-

---------lIa«l18/I1aell---------

- 23 -

__

M_u_l_t_i_t_e_r_m_i_n_a_1_I_n_t_e_r_f_a_c_e_

TRS-SO

®

Service

Manua1

Circuit

Trace Board

1700230,

26-6013,

----------lIadI8/I1aelÏ----------

-

Mu1titerrninal Component

24

-

Interface

Side

Multiterminal

-----------

Interface

TRS-SO

®

Service

Manual

Circuit

Trace

Board

1700230,

26-6013,

---------lIadlo/haell---------

-

Multiterminal

Solder

25

-

Interface

Side

Multiterminal

Interface

~~~.~~

®

~~~~~S_e_r_v_i_c_e~M_a_n_u_a_l~_

Parts

Multiterminal

Item

List

Sym Cl

C2 C3 C4 CS C6 C7 C8 C9 CIO CIl C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24

C25 C26 C27 C28 C29 C30 C31

C32

C33 C34

Interface

Description

Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor,

Capacitor,

Capacitor, Capacitor, Capacitor,

Capacitor,

26-6013

.1

mfd,SOV 390 390

.1

mfd,

.1

mfd,

.1

mfd, 390

390 .1

mfd,

.1

mfd,

.1

mfd,

390 390 .1

mfd,

.1

mfd, 15

pfd, 100

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd,

.1

mfd, 10

mfd,

22

mfd,

.1

mfd,

pfd, pfd,

pfd,

SOV

SOV SOV SOV SOV

SOV

SOV SOV SOV 50V

50V C

50V 50V 50V 50V

50V 50V 50V 50V SOV SOV

50V 50V

50V 50V SOV SOV

50V

SOV

25V

25V 16V

50V

Axial

C

C Axial Axial Axial

C

C Axial Axial Axial

C Axial Axial

Cer

Cer Axial Axial Axial Axial Axial Axial Axial

Axial Axial Axial Axial Axial Axial E1ec E1ec E1ec Axial

Disk Disk

Disk

Axial Axial Axial

Part 8374104

8301394 8301394 8374104 8374104 8374104 8301394 8301394 8374104 8374104 8374104 8301394 8301394 8374104 8374104 8300154 8301103 8374104 8374104 8374104 8374104 8374104 8374104

8374104 8374104 8374104 8374104 8374104 8374104 8374104 8316102 8316102 8316221 8374104

No.

QI RI

R2 R3 R4 R5

Transistor, Resistor,

Resistor, Resistor, Resistor, Resistor,

2N3906

2.2

lIadlO

kohm, kohm, kohm, kohm, kohm,

-

26

1/4W 1/4W 1/4W 1/4W 1/4W

lllaelÏ

-

5% 5% 5% 5%

S%

8100906 8207222

8207222 8207222 8207222 8207222

__

M_u_1_t_i_t_e_r_m_i_n_a_1_I_n_t_e_r_f_a_c_e_

TRS-SO

®

S_e_r_v_l._ec_e_M_a_n_u_a_1

__

Parts

Mu1titermina1

Item

List

Sym R6

R7

R8

R9

RIO

Rll R12 R13 R14 R15 R16 R17

R18

R19 R20 R21 R22

R23

(cont)

Interface

Description

Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor,

N.A. Resistor, Resistor, Resistor, Resistor, Resistor, Resistor,

26-6013

2.2

2.2 560

2.2

2.2 220

1.2

4.7

10

56

4.7

2.2

kohm, kohm, kohm, kohm, kohm, kohm, ohm, kohm, kohm, ohm, kohm,

kohm,

ohm,

kohm, kohm,

kohm,

1/4W 1/4W 1/4W 1/4W 1/4W 1/4W

1/4W

1/4 1/4W

1/4W

1/4W 1/4W

1/4W

1/4W 1/4W 1/4W

5%

5% 5%

5%

5% 5% 5% 5% 5% 5%

5% 5% 5%

5% 5%

5%

Part 8207222

8207222 8207222 8207222 8207222 8207222 8207156 8207222 8207222 8207122

8207212 8207247

8207310 8207056 8207247 8207222 8207222

No.

SWI Ul

U2 U3 U4 U5 U6 U7

U8

U9 U10

Ull U12 U13 U14 U15

U16 017

U18

U19

U20

U21

Switch, IC,

MC1489,

IC,

MC1488,

IC,

MC1489,

IC,

MC1488,

IC,

74LS74,

IC,

MC1489,

IC,

MC1488,

IC,

74LSOO,

IC,

74ALS241,

IC,

74ALS241,

IC,

74LS27,

IC,

74LS74,

IC,

74ALS241,

IC,

74LS04,

IC,

74LS32,

IC,

8251A,

IC,

8251A,

IC,

8253,

IC,

8251A,

IC,

Z8430A,

IC,

74LS138,

SPST

Counter

DIP

Line Line Line Line Dual

Line Line Quad

Octal

Octal Triple Dual

Octal Hex

Quad USART USART

USART

CTC

Decoder

8

Pos

Receiver Driver Receiver Driver Flip Receiver Driver 2-In

Buffer Buffer

3-In

Flip

Buffer

Inverter

2-In

Flop

NAND

NOR

Flop

AND

8489004 8050189

8050188 8050189 8050188 8020074 8050189 8050188 8020000 8025241 8025241 8020027 8020074 8025241 8020004 8020032 8040251 8040251

8041253 8040251

8047882

8020138

---------lIadle/liaell---------

-

27

-

__

M_u_1_t_i_t_e..r_m_i_n_a_1_I_n_t_e_r_f_a_c_e_

TRS-SO

®

S_e_rv_ic_e_M_a_n_u_a_l

__

Parts Mu1titermina1

Item

1

2 3 2 4 1 5

6 3

List

Sym

U22 U23 U24

U25 U26

1 15

4

(cont)

Interface

Description IC,

82S153 8303,

IC, IC,

74ALS240,

IC,

74ALS244,

IC,

7407,

PCB

Logic Pin, Socket, Socket, Socket,

Connector,

Staking

U19,20)

26-6013

Transceiver

Hex Board

20

24

28

Pin Rt

Octal Octal

Buffer

DIP(U22,23) DIP DIP

Angle

Buffer Buffer

(U18)

(U16,17

(J1-3)

Part

8040153 8060303 8025240 8025244 8000007

8709410

8529014

8509009 8509001 8509007

8519109

No.

----------lIadlo

IhaelÏ----------

-

28

-

Multiterminal

-----------

4/

Troubleshooting

Interface

TRS-BO

Service

®

Manual

Correct

when

XENIX Type

Response

There

will

Type

Response

the

in

disable

appear:

disable: disable:

in

cat

lhconsole 09ttyOl 09tty02 09tty04

09ttyOS 09tty06

installation

following

produce

the

will

the

/etc/ttys

the following ttyOX

be

no

ttyOX

/etc/ttys

following

of

commands

noted

command*:

(enter)

response

is

already

not

command:

>/dev/ttyOX

the

Multiterminal typed

responses.

of

the

disabled

updated

(enter)

into

following

Interface

the

(which

computer

error

is

is running

message

OK)

ensured

(or

something

if

redirection)

*

OX=one

"cat

For

/etc/ttys"

of

example,

-----------lIadI8

the

similar

tty

tty04.

--

were

terminaIs,

-

typed

29

it

should

lhaelÏ

-

without

either

look

4,

any

S

the

or

----------

same

output

6.

as

Multiterminal

Interface

~~~_~~®

~~~~~Se~r~v~i~c~e~M~a~n~u~a~l~

----------lIadI8

lhaelÏ

-

30

-

----------

RADIO SHACK, A DIVISION OF TANDY CORPORATION

U.S.A.: FORT WORTH, TEXAS 76102

CANADA: BARRIE, ONTARIO L4M 4W5

TANDY CORPORATION

91

MOUNT

AUSTRALIA

KURRAJONG

DRUITT.

N.S.W.

AVENUE

2770

PARC

BELGIUM

INDUSTRIELDENANINNE

5140

NANINNE

BILSTON

WEST

U.

K.

ROAD

WEDNESBURY

MIDLANDS

WS10

7JN

MS-2606013-1083

PRINTEDINU.S.A.

Tandy TRS-80 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual