Tektronix 4023 User manual

4023

COMPUTER DISPLAY

TERMINAL

SERVICE MANUAL

Tektronix,

Inc.

P.O.

Box

500

Beaverton,

Oregon

97077

MANUAL PART

NO.

070-1617-00

PRODUCT GROUP

11

COMMITTED

TO

EXCELLENCE

Please

Check

for

CHANGE INFORMATION

at

the Rear

of

this

Manual

4023

COMPUTER DISPLAY

TERMINAL

SERVICE MANUAL

First Printing JAN

1974

Revised MAY 1981

1974

by Tektronix, Inc., Beaverton, Oregon.

Printed

in

Contents of this publication may not be reproduced

in

any

form without permission of Tektronix, Inc.

This instrument,

in

whole or in part, may be protected by one

or more

U.S.

or foreign patents

or

patent applications.

Information provided

on

request by Tektronix, Inc.,

P.O.

Box

500, Beaverton, Oregon 97077.

TEKTRONIX is a registered trademark of Tektronix, Inc.

4023

Service

TABLE OF

CONTENTS

SECTION 1 INSTALLATION AND OPERATION Page

Introduction

1-1

Installation

1-1

General

1-1

Mounting

the

Terminal

1-1

Circuitry Access

1-1

Selecting

Strappable

Options

1-1

AC Power Sources and Requirements 1-2

Voltage,

Current,

and Power Requirements 1-2

AC Power Cord and Grounding Requirements 1-6

Power Cord Color Coding 1-6

Spare Switch Connections 1-8

Spare Indicator Connection 1-8

Rear Panel Connectors 1-8

Control Descriptions 1-8

General 1-8

Display

and

Power Controls 1-8

Rear Panel Control 1-9

Console Controls and Indicators 1-9

The Keyboard 1-11

Function

Pad Controls 1-11

Operating Modes 1-13

General 1-13

Direct

Entry

1-13

Buffer

Entry

1-13

Enter Key

Entry

1-13

Send Key

Entry

1-14

Use

of

Message Separators 1-14

Buffer

Form

Fill-Out

Entry

1-14

Transmitting Form Fill-Out Data Via Enter 1-15

Transmitting Form Fill-Out Data Via Send 1-16

Nul Suppression 1-16

SECTION 2 CHARACTERISTICS

Introduction

2-1

Alphabetic Listing 2-2

Tables 2-7

Accessories 2-7

Code

Effect

2-7

Data Coding 2-11

Data Transfer 2-11

Display Specifications 2-12

Editing Specifications 2-13

Environmental Specifications 2-13

Field

Attribute

Codes 2-14

Physical Specifications 2-14

Power

Supply

Specifications 2-15

Reset Key

Functions

2-15

Strap

Options

2-16

Timing Specifications 2-23

SECTION 3 MAINTENANCE

General

Information

3-1

Introduction

3-1

Desk Mounting 3-1

Mounting

the

Terminal

on

the

Optional Pedestal

3-1

Servicing Procedure

3-1

Soldered

Options

3-1

Troubleshooting

Information 3-2

Troubleshooting

Procedure 3-2

Recommended

Troubleshooting

Equipment

3-2

Disassembly and Assembly 3-3

Access

to

the

Display Unit Circuitry 3-3

Keyboard

Information

3-3

REV.

B, DEC.

1974

Circuit Card

Information

3-3

4023

Service TABLE OF

CONTENTS

(cont)

SECTION 3

MAINTENANCE

(Cont)

Page

Rear Assembly Removal 3-3

Monitor

Assembly

Information

3-4

Monitor

Assembly Removal 3-4

CRT

Removal 3-5

Monitor

(CRT) Installation 3-5

Deflection

Amplifier

and High Voltage Board 3-5

High Voltage Transformer Removal 3-5

Silicon Grease 3-5

Power Transformer

Information

3-5

SECTION 4

PERFORMANCE

CHECK/ADJUSTMENT

PERFORMANCE

CHECK

4-1

General

4-1

Performance Check Procedure

4-1

ADJUSTMENT

4-9

Introduction

4-9

Equipment

Required 4-9

Adjustment

Procedure 4-9

Preliminary 4-9

Remove the Terminal Cover 4-9

Detailed Procedure 4-9

SECTION 5

ELECTRICAL

PARTS

LIST

5-1

SECTION 6

THEORY

OF

OPERATION

INTRODUCTION

6-1

GENERAL

DESCRIPTIONS

6-1

Keyboard

6-1

Timing

Card

6-1

Keyboard Interface Card 6-2

Control

Card 6-2

Cursor Card 6-3

RAM

Card 6-3

Edit

Card 6-3

Low

Voltage Power

Supply

6-3

Display

Circuits

6-4

DETAILED

DESCRIPTION 6-4

Keyboard Description 6-4

General 6-4

Coded Character Generation 6-4

Function

Pad

Operation 6-4

Miscellaneous Functions 6-5

Timing

Card 6-5

Timing

6-5

Character Generation 6-7

Retrace Times 6-8

Circuit

Functions 6-9

Miscellaneous 6-11

Keyboard Interface Card 6-11

I

nputting

Keyboard Data 6-11

Control

Character Decoders 6-12

Keygate Generator

With

Repeat 6-12

TSTROBE and CSTROBE

Control

6-12

Move Cursor

Timing

6-12

Move Cursor Gates 6-13

Carriage Return and

Line

Feed

Circuits

6-13

Clear

Page

and

Erase

Input

Circuits 6-13

Page

Full

Circuit

6-14

Wrap-Around

Circuit

6-14

Miscellaneous

Circuits

and Operations 6-14

ii ®

®

TABLE OF

CONTENTS

(cont)

SECTION 6 THEORY

OF

OPERATION (Cont)

Control Card

General Circuitry Information

Miscellaneous Circuits and Operation

Explanation

of

Transmission Control

Cursor Card

General

Register Description

Cursor Register Operation

Display Register Operation

Edit Effects on the Registers

Cursor Addressing and Reading

Miscellaneous Circuits

Summary

of

Register Operations

Random Access Memory (RAM) Card

Introduction

Operation

of

Major Circuits

Sense Amps

Miscellaneous Circuits

Edit Card

Introduction

Edit Circuits

RolI·Up Circuitry

Read Cursor Position

Cursor Positioning

Character Decoding Circuit

Bit 8 and Bit 9

Set

Tab/Backtab Circuits

Display Circuits

General

Vertical

Horizontal

Video

Brightness

Focus

Power Supply

+15·Volt Supply

-12

and

-5·Volt

Supplies

+5·Volt Supply

WIRING AND SIGNAL INFORMATION

Wiring

How

to

Use the Wiring Information

Wire Lists

Minibus Signal Listing and Descriptions

DIAGRAMS

SECTION 7 MECHANICAL PARTS LIST

CHANGE INFORMATION

Page

6·14

6·15

6·16

6·20

6·21

6·23

6·24

6·26

6·27

6·28

6·29

6·30

6·31

6·32

6·33

6·34

6·35

6·44

7·1

4023

Service

iii

4023

Service Fig. 1·

1.4023

Computer

DisPlay

Terminal

.

®

Section

1-4023

Service

INSTALLATION

AND

OPERATION

This manual

is

a

part

of

the

following

set

of

documents

which describe

the

4023

Refreshed

Computer

Display

Terminal:

4023

USERS

MANUAL,

Tektronix

Part No.

070-1621-00.

Contents-An

explanation

of

how

to

operate

and

pro-

gram

the

4023.

4023

SERVICE

MANUAL,

Tektronix

Part No.

070-1617-00.

Contents-A

comprehensive

explanation

of

the

4023.

It

includes

operation,

characteristics, servicing,

adjustment,

circuit

description,

and

parts lists.

Optional

items used

with

the

Terminal are

explained

in

separate

manuals.

INTRODUCTION

The

4023

Computer

Display Terminal interfaces be-

tween

man

and

computer

by

permitting

inputs

through

an

integral

keyboard

and

providing a display

of

computer

output

data.

In

addition,

the

Terminal can relay

data

bi-directionally

between

peripheral devices

and

a

computer.

An Interface

Unit

must

be installed in

the

Terminal

and

connected

to

the

computer-either

directly

or

through

a

modem

(modulator-demodulator)-to

permit

information

interchange.

The

Terminal has

the

ability

to

have copies

made

of

its display, via a Hard

Copy

Unit.

INSTALLATION

GENERAL

Installation consists

of

desk-mounting

the

Terminal,

selecting

the

proper

operating

voltage

and

fuse size,

setting

the

desired

strap

options,

and

connecting

the

Terminal

to

the

computer.

These steps are discussed in

the

following

paragraphs.

MOUNTING

THE

TERMINAL

Desk-Mounting consists

of

simply

setting

the

Terminal

on

a desk

or

other

surface.

The

air vents

on

the

bottom

and

sides

should

be

kept

free

of

obstructions

to

permit

air

flow

through

the

unit.

A dimensional drawing

is

provided in Fig. 1-2 as an

installation aid.

REV.

S,

Dl:C.

1974

CIRCUITRY

ACCESS

The

display

unit

cover

must

be

removed

to

permit

access

to

the

Motherboard

into

which

the

Terminal

Control

cards,

interface cards,

and

optional

accessory

cards

are installed.

Removing

the

display

unit

cover

opens

a line voltage

safety

interlock

switch,

which

automatically

cuts

power

when

the

cover

is

removed.

The

switch

actuator

(located, in

the

top,

left-rear corner) can be pulled

up

to

permit

Terminal

operation

with

the

display

unit

cover removed.

I

WARNING

I

Dangerous voltages exist

in

the display unit

area

when

the line cord

is

connected. Servicing should be done

only

by

qualified technicians.

SELECTING STRAPPABLE OPTIONS

Strappable

options

are movable wire

straps

located

on

circuit

cards inside

the

display

unit,

Figs. 1-3

and

1-4

show

the

strap

option

locations. These

straps

provide

options

for

the

operator

and

programmer

and

can be

set

at

the

user site

by

qualified technical

personnel.

The

circuit

cards (seven

of

them)

plug

into

the

Motherboard.

See Fig. 1-5

for

card

locations

on

the

Motherboard.

1.

Do

not

remove or install circuit cards while the

Terminal power

is

on.

2.

The cards

must

be

installed in the order shown in

Fig.

1-5; otherwise, heat

is

not

dissipated properly.

The

positions

of

the

straps

are

dependent

upon

com-

puter

and

program

requirements,

and

in

some

cases,

upon

user preference.

The

location

and

description

of

the

movable

strap

options

for

the

Keyboard

Interface,

Control,

Timing,

and

Basic Data

Communications

I

nterface

cards are

shown

in

Figs. 1-3 and 1-4.

Information

on

cut-strap

options

can be

found

in

Section

2

of

this

manual.

The

Optional

Data

Communications

Interface

(021-0112-00)

is

to

be installed in P8.

The

Standard

Data

Communications

Interface (021-0111-00)

is

installed

in

P9. Detailed strap-

pable

option

information

for

these

two

interfaces

can

be

found

in

their

respective manuals.

1-1

Installation and

Operation-4023

Service

•

Fig.

1·2.

Physical

Dimensions.

AC

Power

Sources

and

Requirements

Thi

s Te

rminal

is

intended

to be

operated

from

a

sing

le

phase

,

earth

,

referenced

power

source

having

one

current

carrying

conductor

(neutral)

at

ground

(earth)

potential

.

Operation

from

power

sources

where

both

curre

nt-

carrying

conductors

are

live

with

respect

to

earth

(such

as

phase-to-plyase

on a

multiphase

system,

or

across

the

leg

s

of

a

117-234

si

ngl

e

phase

three-wire

system)

is

not

recommend

-

ed

because

on

ly

the line

conductor

has

overcurrent

(fuse)

protection

within

the

instrument.

1-2

This

Terminal

is

designed

tooperate

from

either

a 110

or

220

volt

nominal

line

voltage

source

that

'has a

frequency

of

48

to

440 Hz. In

addition

,

any

of

three

voltage

ranges

for

100 Vac

or

four

voltage

ranges

for

220 Vac may

be selected. Voltage,

current

and

power

requirements

are

listed

below

.

VOLTAGE,

CURRENT,

AND

POWER

REQUIREMENTS

VOLTAGE

FREQUENCY

LINE

FUSE

INPUT

POWER

RANGE

(slo

blow)

100,115,

48Hz

2A

120

or

220 W Max

200,220,

440Hz 1.25A -,

230, 240

REV

. B, DEC.

1974

BUF-position

with

BUFFER

selection

perm

its a

keyboard

CR

to

also

generate

a linefeed.

IN

position

permits

either

a

keyboard

or

computer

gen·

erated

CR

to

generate

a

simultaneous

linefeed.

OUT

position

inhibits

simulta-

neous

linefeeds

with

CR,

regardless

of

CR

origin.

0--.

EOL LF

GEN

I

n-I~J

I

LOCAL

OUT

I

O-_J

LOCAL

enables

line

feeds

to

be

generated

in LOCAL

when

transmitting

from

the

Terminal

buffer

to

an

aux-

iliary device. Line

feeds

are

not

transmitted

to

the

com-

puter

is

on

line_

IN

enables

linefeeds

to

be

generated

by

transmit

circuits

when

operating

in LOCAL

or

ON LINE

with

BUFFER

selected.

OUT

prevents

linefeeds

from

being

generated

at

end

of

a

line.

Ln

o:t

M N

~

~ ~

iii iii iii iii iii

ciqqciq

A.

Keyboard

I

nterface

Card.

B.

Control

Card.

MESSAGE END

The

Message

End

character

is

the

last

character

sent

in a

buffer

or

Read Cursor trans-

mission.

The

standard

END

character

is

strapped

to

be

CR.

Installation and

Operation-4023

Service

LF

DOES

CR

td:~:~

LF

position

performs

a line-

feed

only

upon

receipt

of

a

linefeed

command.

LF/CR

position

causes

a

simultaneous

carriage

return

function

upon

receipt

of

a

linefeed

command.

IN

causes

wrap-around

when

moving

cursor

past

80th

character

position.

OUT

dis-

ables

wrap-around

OUT

is used

when

4023

does

not

require

a

prompt

char-

acter

for

data

transmission

from

buffer

a

line

at

a

time.

IN

is used

when

4023

is

to

receive a

prompt

character

for

data

transmission

from

buffer.

Fig. 1-3A & B.

Options

on

the

Keyboard

I

nterface

and

Control

cards

that

can

be

selected

by

strap

placement.

® 1-3

Installation and

Operation-4023

Service

RESET BLINK

position

causes

cursor

to

blink

when

RESET

key

is

pressed.

BLINK

position

causes cursor

to

blink

continuously.

J222

/0

o o o

TO MODEM

o

BLINK

CURSOR

RESET

BLINK BLINK

A.

Timing

Card.

o o

I

DIRECT

TO CPU

B. I

nterface

Card.

J223

SEND 8

sW2D

o

OUTO

J224

TTY

MASTER

o

SP1

(FAST

1/0)

SP2

D(TAPEFETCH)

o

Fig. 1-4A & B.

Options

on

the

Timing

and

Standard

Interface

card

that

can

be

selected

by

strap

placement.

1-4 ®

Installation and

Operation-4023

Service

"'r-,

•

~

] I

•••••

•

••••

• •

CRT

• • •

••••

•••

",.I

•••••

I

[@I

IIIIIIIIII

P9

+II

BASIC

DATA

COMM

(A9)

IIIIIIIII

@I

[0

11.11.1111

ps+llBLANK(SPAREIIIIIIIIII'1I1

0I

10 111

.....

11

P7

+II

TIMING

(A71

II

..

IIUIIIIII

0 I

[0

1

........

1 P6

+II

CONTROLlA61

1111

..

11

......

0I

(®I

.1111

....

1

P5

+II

EDIT

(A51

111111111.111111

I@]

I I

!0 I

.......

"'P4

+II

KEYBOARD INTERFACE

(A411.

111111 I0 I

I I

!olllllill

III

p3

11tBLANK

(SPAREI I

..

1111111111 101

I I

[011111111111

P2

+IIcuRSOR(A21.11I1I111I111I]

0 I

I I

[@IIIII

..

I

...

PI

+II

RAM

(A1I1.1I11I1

••

IIII..

I@j

I

....

I

• •••••

•••••

•

Fig. 1-5.

Motherboard

(minibus)

connector

assignments.

® 1-5

Installation and

Operation-4023

Service

A fuse

and

a

transformer

jumper

arrangement

permit

the

Terminal

to

be

modified

to

suit

the

voltage

supply.

A

tag

on

the

back

panel

of

the

Terminal

identifies

the

internal

voltage

setting

for

which

the

Terminal

is

wired

when

shipped

from

the

factory

. If.

for

any

reason.

the

jumper

arrangement

is

changed.

changing

the

internal

voltage

setting. cross

out

the

old

setting

and

write

the

new

voltage

setting

on

a tag.

Attach

the tag

to

the rear panel

or

the

line

cord.

The

fuse is located in

the

bottom-left

corner

of

the

back

panel.

The

Transformer

and

jumper

arrangement

are

located

inside the

display

unit

in

the

left

rear

corner

(see

Fig. 1-6).

Removing

the

display

unit

provides

access

to

the

jumper

arrangement.

This

consists

of

removing

two

screws

at

the

top

of

the

rear panel.

The

display

unit

cover

can be removed.

Wiring

instructions

are

shown

on

the

metal

protection

cover

directly

above

the

transformer

wiring

connectors

. See Fig. 1-6.

I

WARNING

I

Dangerous

voltages

exist

at

several

places

inside

the

display

unit

.

Disconnect

the

Terminal

from

the

power

source

before

changing

transformer

connec-

tions.

(In

the

event

the

power

was

on

when

the

cover

was removecJ. a

safety

interlock

switch

disables the

power

supply

.

Pulling

the

switch

up

allows

the

Terminal

to

be

operated

with

the

cover

off

.)

AC POWER

CORD

AND

GROUNDING

REQUIREMENTS

This

instrument

has a

three-wire

power

cord

with

a

three-wire

terminal

polarized

plug

for

connection

to

the

power

source

and safety earth. See Fig. 1-7

for

USA

standard

plugs

.

The

Safety Earth

terminal

of

the

plug

is

directly

connected

to

the

instrument

frame

for

electric-

shock

protection

.

Insert

this

plug

only

in a

mating

outlet

with

a safety earth

contact

or

otherwise

connect

the

frame

of

the

Terminal

to

a

safety

earth system.

The

color

coding

of

the

cord

conductors

is in

accordance

with

recognized

standards as sl;lown below. In

other

jurisdictions

. replace

the

USA

standard

plug

with

a

plug

that

satisfies local

authorities

.

1-6

Fig. 1-6.

Location

of

Transformer

wiring

connectors.

100-120

VAC

(161-

0033

-

00)

1891

-

13

200-240

VAC

(161-0099·00)

Power

Cord

Conductor

Identification

Conductor

Color

Alternate

Color

Ungrounded

(Line)

Brown

Black

Grounded

(Neutral)

Blue

White

Grounding

(Earthing)

Green-Yellow

Fig. 1-7.

Transformer

terminal

jumper

arrangement.

REV. C. OCT.

1976

Installation and

Operation-4023

Service

Under

Side

---,

..--

Component

Side

GND

IMI

D

i5iNG

CLR"X

B a

-5V

VsYi\iC

B

[EI-

KBD

lOCK

(INDICATOR

2)

DMA

STROBE

a a TOP

CURS

lST

Y

CRS

lSI

[!II

BR"EAi<

Y

EQUAL

fffI

[E3

C"SuP

BiT9

E1

[;I

HCU

BUSY

C'CRV

KiI

[EI UP

REsET

~

[!I

HoiViE

SENi58

lSI

[!!I

PAGE

BiTS 8

[E1

EOLoiS

WAi"T

(INDICATOR

1) m

[r!I

MAKE

COPY

4.9

MHz

B

m3

ICE

SP1

(FAST

I/O)

m

[a

x

EQUAL

STEP

8

1:1

Sw1

(SPARE)

STROBE

EI

t:I

Ei\iTE"R

AUX

SENSE

EI

13

SW""2

(SPARE)

DIRECT

(SW) B D

ITFf

EXECUTE

8 D

R"iG"HT

TsITP

B

EJ

BiTs

lST

Y

DIS

1:1

~

BiT2

+15

V B m

+5

VOLTS

-12V

III

Ell

EOl

CRS

HiX

iii

a

~(TAPEFETCH)

BiT"4

iii

m

i50WN

BiT'3 B m

KEYGATE

BiT1 g

1m

lEFT

CURS

BOUNCE

a

~

i5ii.iiA

T

BUSY

m

IIa

HiY

ffiiO

iii

a iJ5CAI (SW 1)

BiT""7

II

a BiT6

T

STROBE

I!iI

II

STORE

READ

iii

E1

DISPLAY

C

STROBE

Ia

I!I

C'Pui\i'T

INDICATOR

3 m

13

614

kHz

CBiJ"SV

1:1

13

GND

Fig. 1-8. Card-edge

connector

assignments.

® 1-7

Installation

and

Operation-4023

Service

SPARE

SWITCH

CONNECTIONS

(SW

1

AND

SW2)

Connection

to

SWITCH 1

and

SWITCH 2

is

provided

at

pin Z and X, respectively. Fig. 1-8 shows location

of

pins Z

and

X

on

the

circuit

card

edge

connectors.

Depressing

the

left side

of

a switch provides a

ground

connection

for

the

respective

switch;

the

other

position

of

the

switch results

in

an

open

circuIt.

SPARE

INDICATOR

CONNECTION

Conn

ection

to

spare Ind

icator

3

is

provided

at

pin 2

of

the

card

-e

dge

connector.

REAR

PANEL

CONNECTORS

J190

-

HARD

COpy

CONNECTOR.

This

is

a fifteen

pin female

connector

with

signals for sending video

out

of

the

4023.

It can be used by

the

Hard

Copy

Unit

or

other

devices for

connections

up

to

200

feet

(15-foot

and

200-foot

cables are avai lable).

VIDEO

CONNECTORS.

The

Monitor

connection

is

a

75-ohm

BNC

connector

for

composite

video.

The

number

of

video

monitors

to

which

the

4023

can provide accept-

able video

depends

on

the

type

of

monitor,

the

cable

distance

to

the

furthest

monitor,

and

the

type

of

connect-

ing cable used. Single

loop-through

is

used, with a single

75-ohm

termination

on

the

end

of

the

string

of

monitors

.

BRIGHTNESS

CONTROL

DESCRIPTIONS

GENERAL

This

information

describes

the

controls

that

can be

manipulated

by

the

operator

at

the

Terminal.

These include

console switches,

alphanumeric

keys,

and

special

purpose

keys

that

control

cursor

positioning, editing, transmission,

and

other

functions.

With

the

exception

of

the

Power

switch,

the

Display

controls,

and

the

Interface

controls,

all

operator

controls

and indicators are located

on

the

keyboard

console. The

Power switch

and

Display

controls

are

on

the

lower right

side

of

the

display

unit

.

The

I

nterface

controls

are located

on

the

back panel

of

the

display unit.

DISPLAY

& POWER CONTROLS

POWER

BRIGHTNESS

CONTRAST

operator

Provides

power

ON-OF F

control

for

the

Terminal.

Adjusts brightness

of

the

char-

acters

. .

Adjust

for

operator

convenience.

Changes

the

difference

in

display

intensity

between

white

and

gray.

Adjust

for

operator

convenience.

CONTRAS

T

,,'OHTNESS

I

conven

ience_

CONTRAST

Fig. 1-

9.

Power

and

Display

controls.

1-8

Changes

the

difference

in

display

intensity

between

white

and

gray.

Adjust

for

operator

convenience.

REV.

B.

DEC.

1974

Installation

and

Operation-4023

Service

REAR PANEL CONTROLS

(Standard Data

Communications

Interface

only)

CONSOLE CONTROLS

AND

INDICATORS

BAUD RATE

SELECTOR

ECHO

IN

OUT

®

An eight .posltlon

rotary

switch

located

on

the

rear panel

that

selects

one

of

eight

data

transfer

speeds

from

the

4023

to

the

computer

.

Figure 1-

11

shows

the

Terminal

cont

/ols divided

into

three

basic groups:

the

Console

Controls

and

Indicators,

the

Keyboard,

and

the

Function

Pad Controls. A brief explana-

tion

of

the

controls

in

each

group

follows.

IN position provides an

"echo"

that

permits

data

to

be displayed

when

transmitting

with

the

DIRECT/

BUFFER

switch

in

DIRECT

.

OUT

position

disables

the

Terminal's

echoing

of

its

own

data

and

would

be used

when

the

computer

pro-

vides an

echo

of

the

Terminal

transmission.

The

console includes light-emitting

diode

indicators

(LED'

s)

and

rocker

switches. Individual descriptions follow.

Power Lamp

Indicator

3

IN

position

provides

an

"echo"

to

permit

data

to

be

displayed

when

transmitt

ing

with

the

DIRECT!

BUFFER

switch

in DIRECT_

OUT

pos

i

tion

disables

the

Ter

-

mi

nal's

echoing

of

its

own

data

and

would

be

used

when

the

computer

provides

an

echo

of

the

Terminal

transmission.

Fig. 1-

10

. Rear panel.

Illuminated

by

the

+5 V

supply

when

the

power

switch

is

turned

on

.

Multiple use lamp whose

function

is

determined

by

the

accessories and

optional

equipment

used

with

the

Terminal.

An

eight

position

rotary

switch

lo-

cated

on

the

rear

panel

that

selects

one

of

eight

data

transfer

speeds

from

the

4023

to

the

1-9

Installation and

Operation-4023

Service

CONSOLE

CONTROLS

AND

INDICATORS

-

nA,IT

'~oc-::

t

LOCAl

ON

LINE

ON

1

Off

ON

2:

Off

DIRECT

SUFfER

POWf

R

Wait Indicator

Keyboard Lock

Indicator

Switch 1

and

Switch 2

Local/On Line

Switch

1-10

THE

KEYBOARD

Fig. 1·

11

.

Keyboard

and

console.

Indicates

that

the

computer

system

cannot

accept data from

the

4023.

Transmission sequence does

not

occur

until

the

light

is

extinguished.

Indicates

that

keyboard

entry

is

inhibited because on of

the

follow-

ing

is

occurring:

1.

The

4023

is

transmitting a mes-

sage

or

a message transmission is

pending.

2.

The

cursor

is

located

in

a

pro

-

tected

field

in

which data

is

not

normally changed.

3. The cursor

is

positioned

on

a

Field

Attribute

Code.

Two

-

position

rocker

switches

whose

functions

are determined by

the

accessories and optional equip-

ment

used with

the

Terminal.

Two

-position r

ocker

switch

that

performs

the

following:

LOCAL electrically disconnects

the

4023

from

the

computer

. However,

the

Terminal can still interact with

other

devices

to

which it may be

Direct/Buffer

Switch

CONTROL

AND

FUNCTION

KEYS

connected.

LOCAL is also used for

operator

familiarization, main-

tenance,

or

any

other

function

that

the

Terminal can perform inde-

pendent

of

the

computer

.

ON

LINE permits

the

4023

to

communicate

with

the

computer

.

Auxiliary devices

connected

to

the

Terminal can

communicate

with

the

computer

and/or

the

Terminal.

Two

-positron rocker switch -

that

provides

the

following functions:

DIRECT causes keyboard entries

to

be

routed

directly

to

the

computer

if

th

e Terminal

is

On Line.

If

in

Local, Keyboard entries are

sent

directly

to

any auxiliary devices

that

may be

connected

to

the

Terminal.

An

echo

(either com-

puter

or local)

condition

must exist

for

keyboard

entries

to

be

displayed.

BUFFER position causes keyboard

entries

to

be

routed

to

the

Terminal

memory

for editing, prior

to

trans-

mitting

the

data

to

the c

ompute

r (if

on

line),

or

to

a peripheral.

®

,THE KEYBOARD

The

Keyboard's

primary

function

is

to

act

as a source of

data

for

the

computer.

The

display

is

used

to

provide a

visual

representation

of

the

keyboard

entries

and

Terminal/

computer

interchange.

The

Keyboard has

encoded

keys

that

generate ASCII

code,

and

function

keys which generate

switch

closures.

Most

of

the

keys are used

only

for

entering

data

and

are

designed

for

single key

entry,

dual key

entry,

and

triple key

entry.

Most are familiar with

typewriter

keys.

The

4023

keyboard

shown

in Fig. 1-9

is

equipped

to

perform

as an

input

for ASCII

or

TTY

codes. ASCII

characters

are shown

on

the

key caps

and

are represented

by

the

key

code

as

follows.

Letter

keys

Number

keys

Control

Character

keys

All

others

Unshifted provide lower case; shift-

ed provides

upper

case.

Unshifted provides

numeral;

shifted

provides

character

shown

on

front

surface

of

key.

Control

character

keys

that

trans-

mit

control

characters are: ESC,

TAB (HT), BACKSPACE (BS), LF,

and RETURN (CR). When these

keys are pressed,

the

appropriate

control

character

is

transmitted

re-

gardless

of

SHI

FT

key position.

U

nsh

ifted

(lower)

or

Shifted

(upper) characters as

shown

on

top

surface

of

key caps.

TTY

LOCK KEYBOARD ENTRY. Lower case letters

(alpha)

characters

cannot

be

transmitted

when

the

TTY

LOCK key

is

depressed, regardless

of

the

position

of

the

SHIFT

key.

REPEAT

ENTRIES. Character transmission occurs when

a key

is

pressed.

If

the

key

is

held

down,

a

0.5

second

delay

(approx.) occurs,

after

which

the

character

is

repeatedly

entered

at

a

10Hz

rate. If CTRL

or

SH I

FT

is

used

with

a

character

key,

the

original selected

code

continues

to

be

transmitted

as long as

the

character

key

is

held

down,

even

if CTR

Lor

SH I

FT

are

subsequently

released.

CONTROL

KEYS.

The

following keys

do

not

directly

enter

characters

for

transmission,

but

control

operation

of

the

keyboard

or

Terminal.

Some

of

them

are used

independently,

while

others

are used in

combination

with

other

control

keys

or

character

keys.

Installation

and

Operation-4023

Service

PAGE-ERASE INPUT When pressed alone, causes

all

unprotected

data

stored

in Ter-

minal

memory

to

be erased,

and

the

cursor

moves

to

the

home

position.

This

function

is

normally

used

with

formatted

displays. When pressed

while SHI

FT

is

held

down,

per-

forms a PAGE

function.

The

memory

is

cleared,

the

logic

is

set

to

initial

condition,

and

the

cursor

moves

to

home.

CTRL Causes

letter

keys

to

transmit

con-

trol

characters

if CTRL

is

held

down

before

the

letter

key

is

press-

ed.

It may be used in

conjunction

with SH I

FT

and

a

character

key

to

form

a

control

character.

SHIFT

TTY LOCK

BREAK

RUBOUT

Performs

no

function

when

used

alone. When held

down,

it causes

some

keys

to

enter

a

shifted

character

while

the

character

key

is

pressed. It

is

also used in com-

bination

with

CTR

L

and

some

letter

keys

for

entering

control

characters.

Causes

letter

keys

to

transmit

the

TTY

character

set,

regardless

of

position

of

SH I

FT

key.

The

following are

not

transmitted:

\ } ;

'"

Generates a BREAK signal, which

is

sent

to

the

interface

unit.

Any

resulting

interrupt

signal

is

interface

dependent.

Not

a

control

key

but

a

character

key. When pressed,

the

RUBOUT

(127

10

)

character

is

transmitted.

Use

of

this key

is

program

dependent.

FUNCTION PAD CONTROLS

This useful, dual-purpose

group

of

controls

is

located

to

the

right

of

the

keyboard.

They

provide

control

over

data

transmission, editing,

cursor

positioning,

and

reset func-

tions. With

the

NUM LOCK key pressed, these keys

function

as

a

numeric

pad

to

aid in

entry

of

numeric

data.

RESET A multiple

purpose

key

that

per-

forms

the

following (depending

on

operating

configuration):

1.

BI

inks

the

cursor;

cursor

quits

blinking when key

is

released.

®I

REV. APR 1974

1-11

Installation

and

Operation-4023

Service

ERASE

TO

END

COpy

INS L

INSC

1-12

2. Pressing

RESET

while

simul·

taneously

entering

a

control

char-

acter

will

store

that

control

char-

acter

in

Terminal

me":10ry.

3.

If

the

optional

Rulings Char-

acter

Set

has

been

installed

and

selected,

pressing

RESET

causes

the

standard

character

set

to

be re-

selected.

4.

RESET

terminates

a

buffer

transmission.

5.

Inhibits

an

LCE

condition

as

long as

RESET

is

held

down.

(See

LCE signal

description

in

"Defini-

tion

of

Line

Titles"

in

Section

6.)

6. Clears a Make

Copy

request

(will

not

terminate

a

copy

in progress).

7. With

formatted

displays,

holding

RESET

down

enables

data

to

be

keyed

into

a

protected

field:

Alpha

characters

can also

be

keyed

into

a

non-alpha

field.

8. With

formatted

displays, press-

ing

ERASE

TO

END

with

RESET

held

down,

causes

erasure

of

data

in

a

protected

field

from

the

cursor

position

to

the

end

of

that

field

(or

the

end

of

the

line).

9. When using 4-line roll-up, press-

ing

RESET

allows 4

more

lines

to

roll-up (used

with

flagged

interfaces

only).

With a

formatted

display,

pressing

this

key

when

the

cursor

resides in

an

unprotected

field causes

erasure

of

all

data

from

the

cursor

location

to

the

end

of

that

field. With

no

fields

contained

in a line,

data

is

erased

from

the

cursor

position

to

the

end

of

the

line.

With a Hard

Copy

Unit

connected

to

the

Terminal,

pressing

this

key

activates

the

Hard

Copy

Unit

to

make

a

copy

(on

paper)

of

the

displayed

information.

Pressing

this

key

without

SHI

FT

causes

an

Insert

Character

function.

A

SPACE

character

is

entered

at

the

cursor

location,

and

data

at

the

cursor

position

and

to

the

right

of

the

cursor

moves right.

Data

moved

past

the

right

margin

is

lost.

The

function

repeats

if

the

key

is

held

DEL

L

DEL

C

SEND

ENTER

CURSOR

(Direction

Shift)

Keys

HOME

NUM LOCK

down.

Pressing

with

SHIFT

causes

an

Insert

Line

function.

The

line

where

the

cursor

resides moves

down

one

line,

with

all lines

below

doing

likewise.

Data

in

the

24th

line

is

lost.

The

cursor

remains

stationary

and

the

line

where

it

resides

is

filled

with

SPACE (SP)

characters.

This

function

also re-

peats

when

the

keys

remain

held

down.

Pressing

this

key

without

SHI

FT

causes

the

character

at

cursor

loca-

tion

to

be

deleted.

All

characters

to

right

of

cursor

move

left

one

posi-

tion.

A NU L

character

resides

at

the

right-most

character

position

on

the

line.

This

function

also

repeats.

Pressing

with

SHI

FT

causes a

Delete Line

function.

The

line

where

the

cursor

resides

is

lost

and

replaced

by

the

line

immediately

below.

All

other

lines

below

also

move

up

one

line.

The

line

vacated

by

the

last line

moved

up

is

filled

with

NUL

characters.

This

function

also

repeats

when

the

keys

remain

held

down.

Pressing

this

key

without

SHI

FT

initiates

the

Enter

transmission

sequence.

Pressed

with

SHI

FT

initiates

the

Send

transmission

seq

uence. (See

Operation

De-

scriptions

for

explanation

of

Enter

and

Send.)

A

group

of

four

non-encoded

keys

that

provide

directional

movements

of

left,

right,

up,

and

down

for

the

cursor.

A

momentary

push

moves

the

cursor

one

character

or

line

position

in

the

direction

indicated

on

the

key

cap.

Holding

the

key

causes

the

function

to

repeat.

Moves

the

cursor

to

the

home

position.

Home

is

the

first

character

position

of

the

first line. (Also

terminates

a

buffer

transmission.)

Pressing

this

switch

enables

func-

tion

Pad

keys

to

be

used as a

numeric

pad.

Specific

numeric

inputs

provided

by

individual keys

are

embossed

on

the

front

surface

of

the

key

caps. NUM LOCK

must

be

pressed a

second

time

to

restore

normal

Function

Pad

Controls.

®

OPERATING

MODES

GENERAL

The

4023

is

both

a

transmitting

and

a receiving device.

Standard

interface

hardware

provides Full Duplex

only.

Full

or

Half Duplex can be achieved

by

use

of

an

Optional

Data

Communications

Interface. Data can be

transmitted

to

the

computer

directly

from

the

keyboard,

from

the

keyboard

via

the

Terminal

buffer

(memory),

or

from

an

optional

auxiliary

unit.

Data received by

the

Terminal can

be displayed,

or

can

control

other

functions

in

the

Terminal

or

at

auxiliary units.

Data

transmitted

to

the

computer

can be

echoed

back

to

the

receiving circuits

by

the

computer,

the

modem,

or

by

selecting Local

Echo

at

the

interface

unit.

Under Local

Echo

conditions,

data

from

the

keyboard

or

auxiliary

unit

is

simultaneously

sent

to

the

computer

and

the

4023

receiving circuits. Printable

characters

from

the

computer

enter

the

Terminal

memory

and

are displayed.

The

com-

puter

can

write

anywhere

on

the

screen regardless

of

fields.

The

LOCAL/ON

LINE switch

must

be

in

the

ON LINE

position

to

communicate

with

the

computer.

The

LOCAL

position

allows

the

Terminal

to

operate

independent

of

the

computer.

Local

operation

permits

keyboard

or

auxiliary

unit

data

to

be

written

on

the

display

or

otherwise

executed

by

the

Terminal.

The

Data

Entry

Modes are: Direct

Entry,

Buffer

Entry,

and

Buffer

Form

Fill-out

Entry.

They

function

as

follows:

(Table 2-4 in

Section

2 provides a brief description

of

data

transfer

in

DIRECT

and

BUFFER.)

NOTE

The

fol/owing

is

a discussion

of

operation

of

the

standard Terminal. Strappable options and

other

optionscan

modify

the description.

DIRECT

ENTRY

Placing

the

DIRECT/BUFFER

switch

to

DIRECT

sets

the

Direct

Entry

Mode. This

mode

is

interactive by

character

(similar

to

Teletype).

Destination

of

data

depends

on

the

position

of

the

LOCAL/ON LINE switch.

In

the

ON

LI

NE

position,

data

entered

from

the

keyboard

(keyed

data)

is

sent

directly

to

the

computer.

Data

from

the

keyboard

is

not

sent

to

the

Terminal

memory

for

display

unless

the

computer

echoes

the

data,

or

the

modem

or

the

interface

unit

supplies local

echo.

Roll-up

occurs

with

a

®

Installation

and

Operation-4023

Service

cursor

movement

past

the

last line

on

the

display. When ON

LINE,

the

Direct

Entry

Mode can

operate

in full

or

half

duplex

(depending

on

the

interface

unit

used). Placing

the

LOCAL/ON LINE switch

to

LOCAL causes all

keyboard

data

to

go

directly

to

the

auxiliary device (such as a mag

storage

unit).

The

data

is

not

sent

to

the

Terminal

memory

for

display, unless a local

echo

condition

exists.

BUFFER

ENTRY

This

mode

is

set

when

the

DIRECT/BUFFER

switch

is

set

to

BUFFER.

Keyed

data

is

stored

in

memory

and

is

displayed, allowing

text

editing

before

data

entry.

Buffer

Entry

Mode

is

used

for

either

non-formatted

or

formatted

operations.

When no Field

Attribute

Codes (FACs) are used,

the

entire

message

is

transmittable.

Video

is

displayed

white

on

black

background

with

normal

intensity.

Pressing

either

the

ENTER

or

SEND

key

initiates

the

buffer

transmission

sequence.

As

in

the

Direct

Entry

Mode,

the

destination

of

data

is

determined

by

the

position

of

the

LOCAL/ON LINE

switch.

ENTER

KEY

ENTRY.

Pressing

the

ENTER/SEND

key

without

SH

I

FT

causes an ETX

code

(A Message

Separator)

to

store

in

memory

(if display

is

non-formatted)

at

the

cursor

location.

Storing

the

ETX in

memory

causes a

rectangular

marker

to

be displayed

at

the

cursor

positiurl.

The

cursor moves rapidly back

through

the

text,

seeking

either

a

start

of

text

message (previous Message

Separator)

or

the

home

position,

then

sends

the

stored

message.

Transmission

of

data

continues

until

the

cursor

reaches

the

ETX

code,

at

which

time

the

Terminal sends

an

End

Code

and

performs a carriage

return.

(The

End

Code

can

be

strapped

to

be

any

desired

control

character.

Standard

strap

setting

is

for a CR code.)

Fig. 1-12

is

an illustration

of

the

4023

display

during

a

typical

4023/computer

entry

interchange

using

the

buffer.

Assume

that

the

cursor

was originally

at

the

home

position.

The

operator

keys

into

the

Terminal

memory

the

first line,

edits if necessary,

then

presses

the

ENTER

key.

The

cursor

moves rapidly

back

through

the

text,

searching

for

a

previously

stored

Message

Separator

or

the

home

position,

in

this

case,

the

home

position.

Data

entry

then

begins

at

the

home

position.

Data

entry

continues

to

the

ETX

code

that

was

stored

when

the

ENTER key was pressed,

at

which

time

the

4023

sends an End Code

and

performs

a carriage

return functi

on.

The

first

character

of

the

computer

response

is

an LF

(line feed)

code

that

positions

the

cursor

down

one

line.

Thus

combined

with

the

carriage

return

executed

by

the

Terminal,

the

cursor

is

positioned

to

the

first

character

position

of

a

new

line.

Computer

response

continues

...

1-13

Tektronix 4023 User manual

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