Digital PDFs

EK-VT220-UG-003

December 1984

140 pages

Original

21MB

Document:	VT220 Owners Manual
Order Number:	EK-VT220-UG
Revision:	003
Pages:	140
Original Filename:	http://bitsavers.org/pdf/dec/terminal/vt220/EK-VT220_UG-003_VT220_Owners_Manual_198412.pdf

OCR Text

VT220
Owner's Manual

EK-VT220-UG-003

VT220
Owner's Manual

Digital Equipment Corporation

1st Edition, Aug ust 1 983
2nd Edition, July 1984
3rd Edition, December 1984
Copyright © 1983, 1984 by Digital Equipment Corporation.
A" Rights Reserved.
Printed in U.S.A.
The reproduction of this material, in part or whole, is strictly prohibited. For copy
information, contact the Educational Services Department, Digital Equipment
Corporation, Maynard, Massachusetts 01754.
The information in this document is subjectto change without notice. Digital Equipment
Corporation assumes no responsibility for any errors that may appear in this document.
This equipment generates and uses radio frequency energy and if not installed and
used properly, that is, in strict accordance with the manufacturer's instructions, 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 specifications in Subpart J of Part 15 of FCC Rules, which are designed to provide reasonable
protection against such interference in a residential installation. However, there is no
guarantee that interference wi" 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 correct the
interference by one or more of the following methods:
•
•
•
•

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 different branch circuits.

If necessary, the us~r should consult the dealer or an experienced radio/television
technician for additional suggestions. The user may find the booklet Howto Identifyand
Resolve Radio/TV Interference Problems, prepared by the Federal Communications
Commission, helpfuL This booklet is available from the U.S. Government Printing Office,
Washington, DC 20402, Stock No. 004-000-00345-4.
AT&T is a trademark of American Telephone and Telegraph Company.
Mate-N-Lok is a trademark of AMP, Inc.
The following are trademarks of Digital Equipment Corporation, Maynard, Massachusetts.

mamaama
DEC
DECmate
DECnet
DECsystem-10
DECSYSTEM-20

DECtaik
DECUS
DECwriter
DIBOL
LA
·MASSBUS

PDP
P/OS
Professional
Rainbow
RSTS
RSX

UNIBUS
VAX
VMS
VT
Work Processor

CONTENTS

INTRODUCTION
CHAPTER 1

A LOOK AT THE TERMINAL

General...............................................................
VT220 Components. ............................. .....................
Monitor/System Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard...... ............................. .....................
How the VT220 Works .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating States .....................................................
Set-Up...........................................................
On-Line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local............................................................
Operating Modes .....................................................
VT200 Mode, 7-Bit Controls .....................................
VT200 Mode, 8-Bit Controls .....................................
VT100 Mode... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VT52 Mode......................................................
Character Set Modes .................................................
CRT Saver Feature ...................................................

1
1
2
2
2
2
2
3
3
3
3
4
4
4
4
4

iii

E\-

CONTENTS

CHAPTER 2

CONTROLS, INDICATORS, AND CONNECTORS

General...............................................................
Terminal..............................................................
Monitor..........................................................
Keyboard.............................................................
Main Keypad .........................................................
Tab..............................................................
Ctrl ..............................................................
Lock... ..........................................................
Shift... ...... ...... .. ............... .. ...... .....................
Return. .... ......................... .......... ..... ..............
<::Kl (Delete) ..................................................
Compose Character .............................................
Editing Keypad .......................................................
Auxiliary Keypad......................................................
Top-Row Function Keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hold Screen ............................................. ... . . . . . .
Print Screen ................................................... ,.
Set-Up. ............................. .............................
Data/Talk..... .... .................. ............... ..............
Break............................................................
F11 (ESC) .......................................................
F12 (BS) .........................................................
F13 (LF) ......................... ........................ .... ....
Function Key Summary...... ....... ....... ............ ..........
Visual Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hold Screen Indicator ...........................................
Lock Indicator...................... ....... ......................
Compose Indicator ..............................................
Wait Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audible Indicators ....................................................
Keyclick .........................................................
Bell..............................................................

CHAPTER 3

5
5
9
10
10
10
11
11
11
11
12
12
12
13
13

14
14
14
14
14
15
15
15
16
16
16
16
16
16
16
17

OPERATING PROCEDURES

General...............................................................
Printing ...............................................................
Normal Mode ....................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Print Mode .................................................
Printer Controller Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local Controller Mode.............. .............................

19
19
20
20
20
21

CONTENTS

Optional Modem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Composing Characters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Using a Three-Stroke Compose Sequence . . . . . . . . . . . . . . . . . . ..
Using a Two-Stroke Compose Sequence. . . . . . . . . . . . . . . . . . . . ..
Aborting or Restarting a Compose Sequence . . . . . . . . . . . . . . . . ..

21
21
23
23
24

CHAPTER 4 TERMINAL SET-UP
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Using Set-Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Set-Up Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Screen Title. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Terminal Identifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Firmware Version Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Status Line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Fields. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Set-Up Controls and Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Set-Up Example: Changing Features. . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Set-Up Screen Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Set-Up Directory Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Display Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
General Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Communications Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Printer Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Keyboard Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Tab Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

35
36
36
37
37
38
38
39
40
41
42
44
49
53
58
64
69
75

CHAPTER 5 COMMUNICATION
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Host and Printer Port Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Modems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Character Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Terminal - Host Data Flow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Conditions That Send XON. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Conditions That Send XOFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Buffer Overflow Prevention. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Use of Fill Characters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Connect/Disconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Terminal - Printer Data Flow Control. . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Note on Printer Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

77
78
78
83
84
84
85
85
86
86
87
88
88
88

CONTENTS

CHAPTER 6

PROBLEM SOLVING

General...............................................................
Common Operating Problems ........................................
Power-Up Self-Test.. ... .......... ..... .. ...... . ... .. ....... ..... .....
Performing the Power-Up Self-Test...................................
Digital Service ........................................................

89
89
91
91
92

APPENDIX A SPECIFICATIONS
General...............................................................
VT220 Specifications .................................................

93
93

APPENDIX B OPTIONS, DOCUMENTATION, AND SUPPLIES
General...............................................................
Available Options .....................................................
Modems.........................................................
Cables...........................................................
Related Documentation......................... ......................
Specifications ........................................................
Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX C

97
97
97
97
98
99
99

KEYBOARDS

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 101
INDEX

CONTENTS

vii

FIGURES
1-1
VT220 Video Terminal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
2-1
Terminal Controls, Indicators, and Connectors ................
6
2-2
Monitor Controls and Tilt Leg Release Button. . . . . . . . . . . . . . . . .
8
2-3
. Keyboard (North American) ...................................
9
2-4
Main Keypad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2-5
Editing Keypad.... .......... ................... ............... 12
2-6
Auxiliary Keypad .............................................. 12
2-7
Top Row of Function Keys and Visual Indicators.............. 13
4-1
Set-Up Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4-2
Sample Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4-3
Set-Up Directory Screen.. .. .... ............... ....... ........ 44
4-4
Display Set-Up Screen......................... ............... 49
4-5
General Set-Up Screen ....................................... 53
4-6
Communications Set-Up Screen .............................. 58
4-7
Printer Set-Up Screen........... ............... ............... 64
4-8
Keyboard Set-Up Screen............ ........... ........... .... 69
4-9
Tab Set-Up Screen.............. ........ ....... ............... 75
5-1
Cables........................................................ 83
5-2
Character Format ............................................. 84
6-1
Successful Power-Up Screen Message ....................... 91
C-1
North American ............................................... 102
C-2
United Kingdom ............................................... 103
C-3
Belgium (Flemish) ............................................. 104
C-4
Canada (French) .............................................. 105
C-5
Denmark ....................................... . . . . . . . . . . . . . .. 106
C-6
Finland. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 107
C-7
France/Belgium ............................................... 108
C-8
Germany/Austria .............................................. 1 09
C-9
Holland. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 110
C-10 Italy ........................................................... 111
C-11
Norway ........................................................ 112
C-12 Spain ......................................................... 113
C-13 Sweden. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 114
C-14 Switzerland (French) .......................................... 115
C-15 Switzerland (German) ......................................... 116

viii

CONTENTS

TABLES

2-1
2-2
3-1 .
3-2
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
5-1
5-2
5-3
6-1
6-2

Terminal Controls, Indicators, and Connectors ................
Monitor Controls and Tilt Leg Release Button. . . . . . . . . . . . . . . . .
Valid Compose Sequences: Multinational Mode. . . . . . . . . . . . . . .
Valid Compose Sequences: National Mode ...................
Status Line Messages ........................................
Set-Up Controls and Cursor Functions.. . . . . . . . . . . . . . . . . . . . . . .
Set-Up Screens Summary. . . .. . . . . . . . . . . . . . . . .. .. .. . . . .. .. . . . .
Set-Up Directory Screen ......................................
Display Set-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Set-Up Screen .......................................
Communications Set-Up Screen ..............................
Printer Set-Up Screen.........................................
Keyboard Set-Up Screen.. ....................................
Tab Set-Up Screen. . . .. . .. .. .. . .. .. . .. .. . . . .. .. . .. . . .. . . ... .. .
Comm Port EIA Interface Signals .............................
20 mA Port Interface Signals..................................
Printer Port EIA Interface Signals.............................
Common Operating Problems. . .. . . .. . . . . . . .. . . . .. . .. . .. .. .. . .
Screen Error Messages ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6
8
24
29
38
40
43
45
50
54
59
65
70
76
79
81
81
89
92

INTRODUCTION

This manual provides the information you need to operate and maintain your
VT220 video terminal. The manual is organized into six chapters and three
appendices as follows.
• Chapter 1, "A Look at the Terminal," introduces you to the VT220 terminal. This chapter provides an overview of what the terminal is and what it
does, then briefly describes how it works.
• Chapter 2,."Controls, Indicators, and Connectors," describes the terminal
controls, indicators, and connectors, and shows their locations.
• Chapter 3, "Operating Procedures," provides information on specific terminal functions and operating procedures.
• Chapter 4, "Terminal Set-Up," describes each set-up screen feature in
detail. This chapter shows you how to select set-up features to define the
terminal's operating characteristics.
• Chapter 5, "Communication," describes how the VT220 terminal communicates with a host computer and a peripheral device such as a printer.
• Chapter 6, "Problem Solving," describes the self-test used to find terminal hardware problems. This chapter also contains simple troubleshooting information to correct common operating problems.

INTRODUCTION

• Appendix A, "Specifications," provides all VT220 terminal specifications.
• Appendix B, "Options, Documentation, and Supplies," describes the
options, related documentation, and supplies mentioned in this manual
and how to order them.
• Appendix C, "Keyboards," shows the various keyboards available with
the VT220 terminal.

A LOOK AT THE TERMINAL

GENERAL

This chapter introduces you to the VT220 terminal. The chapter provides an
overview of what the terminal is and what it does, then briefly describes how
the terminal works.
VT220 COMPONENTS

The two main components of the VT220 terminal are the monitor/system unit
and the keyboard (Figure 1-1).

MA·1005-83

Figure 1-1

VT220 Video Terminal

A LOOK AT THE TERMINAL

Monitor/System Unit

The monitor/system unit (referred to as the terminal from this point on) consists of a monochrome cathode-ray tube (CRT), a terminal controller board,
and a power supply/monitor board.
Keyboard

The low-profile keyboard has four groups of keys and four visual indicators.
The main keypad operates like a typewriter keyboard. A single coiled cable
connects the keyboard to the terminal.
There are 15 basic keyboards available with the VT220. (See Appendix C.)
Each keyboard is for a different language.
HOW THE VT220 WORKS

The VT220 is a general-purpose video display terminal that lets you interact
with a software application program. You send characters to the application
program by typing on the keyboard. Characters sent by the application program appear as text on the terminal screen. You can print the text you create
on the terminal if the terminal is connected to a printer. The terminal operates
by executing standard American National Standards Institute (ANSI) functions.
OPERATING STATES

The VT220 has three operating states you can select from the keyboard.
• Set-up
• On-line
• Local
Set-Up

The set-up state lets you select or examine terminal operating features. Chapter 4 describes these set-up features in detail. You also use set-up to select the
on-line and local states.
You select set-up from the keyboard by pressing the Set-Up key.

A LOOK AT THE TERMINAL

On-Line

The on-line state lets the terminal communicate with a host computer. Data
entered at the keyboard is sent to the host computer. Data received from the
host computer is displayed on the monitor. You can also display data entered
from the keyboard on the screen, if you select the local echo feature in set-up
(Chapter 4).
You can only select on-line in set-up.
Local

The local state lets you place the host computer on hold. Data entered at the
keyboard is sent to the monitor, but not to the host computer. Data received
from the host computer is stored; this data is sent to the monitor after you put
the terminal back on-line.
You can only select local in set-up.
OPERATING MODES

The VT220 has four major operating modes. You can select these modes in
set-up. The default operating mode is VT200 mode, 7-bit controls. A default
setting is a factory setting the terminal uses until you change that setting.
• VT200 mode, 7-bit controls
• VT200 mode, a-bit controls
• VT100 mode
• VT52 mode
VT200 Mode, 7 -Bit Controls

This mode executes standard ANSI functions and lets you use the full range of
VT220 capabilities. You should use this mode with application programs that
expect 7-bit control characters, and either DEC multinational characters or
national replacement characters (depending on the character set selected in
set-up).

NOTE: In general, most VT100 application programs will run in VT200 mode,
7-bit controls.

A LOOK AT THE TERMINAL

VT200 Mode, 8-Bit Controls

This mode also executes standard ANSI functions and lets you use the full
range of VT220 capabilities. You should use this mode with application programs that expect 8-bit control characters and DEC multinational characters.
VT100 Mode

This mode executes standard ANSI functions. You should use vn 00 mode
with application programs that require strict compatibility with Digital's VT100
terminal.
VT52 Mode

This is a text mode that executes Digital (DEC) private functions (not ANSI).
You should use VT52 mode for compatibility with existing application programs
designed for Digital's VT52 terminal.
CHARACTER SET MODES

The VT220 has two basic character set modes, multinational and national.
Multinational mode supports the DEC multinational character set (DEC MCS).
The DEC MCS is an 8-bit character set that contains most characters used in
the major European languages. The ASCII character set is included in the DEC
MeS.
National mode supports the national replacement character (NRC) sets. The
NRC sets are a group of eleven 7-bit character sets. You can only use one
NRC set at a time. The NRC set available depends on the keyboard selected in
set-up (Chapter 4). National mode restricts compatibility to a 7-bit environment,
so the DEC MCS is not available.
CRT SAVER FEATURE

If during normal operation the terminal is inactive for 30 minutes (no keyboard
activity or input from a host computer), the monitor screen goes blank (but data
is not lost). Keyboard activity or input from the host computer activates the
monitor again. To reactivate the screen, press the Ctrl key.
NOTE: This manual describes the use of the North American keyboard,
unless otherwise specified. When you use the North American keyboard, the
terminal defaults to multinational mode. (National mode is disabled.)

CONTROLS, INDICATORS,
AND CONNECTORS

GENERAL

This chapter provides information about the terminal's controls, indicators, and
connectors. The chapter also describes the keyboard, including the three
keypads and special function keys.
TERMINAL

The terminal controls, indicators, and connectors are shown in Figures 2-1 and
2-2 and described in Tables 2-1 and 2-2.

Monitor
The monitor controls are shown in Figure 2-2 and described in Table 2-2.

CONTROLS, INDICATORS, AND CONNECTORS

CURSOR

POWER ON/OFF

COMPOSITE VIDEO
OUTPUT CONNECTOR

20mA HOST
PORT CONNECTOR

Figure 2-1

PRINTER PORT
CONNECTOf:!

Terminal Controls, Indicators, and Connectors

MA-0B65A-B3

CONTROLS, INDICATORS, AND CONNECTORS

CONTROLS, INDICATORS, A ND CONNECTORS

c:Z: :w;-:;::~~
min

CONTRAST
CONTROL

Figure 2-2

BRIGHTNESS
CONTRO L

MA.0843-83

Monl"tor Controls and Tilt Leg Re Iea se Button

CONTROLS, INDICATORS, AND CONNECTORS

VISUAL INDICATORS
I " - - - - - - - - - - T O P ROW FUNCTION K E Y S - - ' - - - -'- - -

DDDDD 00000 DODD
[J[][[][][][[][[][D(][D[][][;]E]
DEJEJU[J~r:J~DEJ~[][]D··"

ur=J[J[][]D[][][][]DDDD

',----~

DODD

EJLJLJLJ

[][][][J

r:=J[][][]D[]~[]~DD[]L::J

II~I

L : - - - - - M A I N KEYPAD - - - - - - - l .
MA·0646P·S3

Figure 2-3

Keyboard (North American)

KEYBOARD
The keyboard (Figure 2-3) consists of the following parts.
Main keypad
Editing keypad
Auxiliary keypad
Top-row function keys
Four visual indicators
Two audible indicators

CONTROLS, INDICATORS, AND CONNECTORS

EJD[J[J[](]~[]~[][[]LJ~EJ

DEJE][][][][] [][J[J[][][JD"um

DLJEJ[JEJDEJEJ[][JDDDD .
,"hi" 1[][][J[]tJ[][]~DD[]IShi" I
I
Figure 2-4

Main Keypad

MAIN KEYPAD

This keypad (Figure 2-4) operates like a standard typewriter keyboard.
The main keypad has the following special function keys.

Tab

Pressing the Tab key sends a horizontal tab, which normally moves the cursor
to the next tab stop.

Ctrl

Holding down the Ctrl key and pressing another key sends a control code to
the system. A control code tells the system to perform a predefined operation.
In this manual, keyboard control functions using Ctrl appear as follows.
Ctrl-(other key)

For example, Ctrl-Z means to press and hold Ctrl while pressing the Z key.

CONTROLS, INDICATORS, AND CONNECTORS

FI
L-.J Lock
Pressing the Lock key down makes the alphabetic keys send uppercase characters. Pressing Lock again makes the alphabetic keys send lowercase characters. Lock is similar to the Shift Lock key on a typewriter.

Shift

Holding down the Shift key and pressing another key sends uppercase characters, or the top symbol on two-character keys.
In some cases, you use Shift with another key to send a predefined control
function. In this manual, a keyboard control function using Shift is shown as
follows.
Shift-(other key)

For example, Shift-Print Screen means to press and hold Shift while pressing
the Print Screen key.

Return

Pressing the Return key sends either a carriage return or a carriage return and
line feed (selected in the General Set-Up screen, Chapter 4). In some cases,
Return moves the cursor to the next line when editing text. In others, Return is
a signal to the system that a particular operation is complete.

~
~

(Delete)

Pressing the <:K.l (delete) key sends a DEL (delete) character. Normally
<:K.l (delete) erases one character to the left of the cursor. Typing Shift<:K.l (delete) sends a CAN (cancel) character.

CONTROLS, INDICATORS, AND CONNECTORS

Compose
Character

This key lets you create characters that do not exist as standard keys on your
keyboard. See the "Composing Characters" section in Chapter 3 to use this
key.
EDITING KEYPAD
Normally, you use the editing keypad (Figure 2-5) to control the cursor and edit
data that you already entered.
In a typical editing operation, the four arrow keys move the cursor in the
direction indicated by the arrow. The six editing keys have functions
corresponding to their legends. See your application software manual for
specific information.
AUXILIARY KEYPAD
The auxiliary keypad (Figure 2-6) lets you enter numeric data as you would with
a standard calculator. Some keys (PF1, PF2, PF3, and PF4) may have functions
assigned by the application software. See your application software manual for
specific information.
The Enter key can cause a carriage return or a carriage return and line feed,
depending on the General Set-Up screen selection. You also use Enter in setup, to activate a selected feature.

EJEJEJEJ
[JEJEJ[J

[][J[]D

DDEJDnte.

Figure 2-5

Editing Keypad

1°

Figure 2-6

Auxiliary Keypad

CONTROLS, INDICATORS, AND CONNECTORS

Hold
Screen

Datai

Break

Talk

F10

DDDDD DDDDD
~

___A~___

00000 00000

DDDD BI
DDDD
F11
(ESC)

F12
(85)

F13
(LF)

F14

Hold Screen

lock

Compose Wait

F17

F18

F19

F20

Figure 2-7 Top Row of Function Keys and Visual Indicators

TOP-ROW FUNCTION KEYS
Most of the top-row function keys (Figure 2-7) have functions assigned by the
application software. Your application software manual should describe the
function of these keys. The following paragraphs describe the predefined toprow keys.
Hold
Screen

Hold Screen

Pressing the Hold Screen key freezes the screen display and stops any new
characters from being displayed. The Hold Screen indicator comes on when
you press this key. Pressing Hold Screen again returns the terminal to normal
operation and turns off the Hold Screen indicator.

CONTROLS, INDICATORS, AND CONNECTORS

Print
Screen

Print Screen

Pressing the Print Screen key sends the text on the screen to the printer.
Typing Ctrl-Print Screen sets or resets auto print mode. See the "Auto Print
Mode" section in Chapter 3.
Set-Up

Set-Up

Pressing the Set-Up key causes the terminal to enter or exit the set-up state.
(See Chapter 4.)
Datal
Talk

Data/Talk

The Data/Talk key only operates if EIA modem controls are enabled. (See
Chapter 3.)
Break

Break

The Break key works alone or with other keys to perform an operation.
• Pressing Break alone sends a break if break is enabled in set-up. (See the
"Keyboard Set-Up Screen" section in Chapter 4.)
• Typing Shift-Break starts a disconnect. (See the "Connect/Disconnect"
section in Chapter 5.)
• Typing Ctrl-Break sends the answerback message to the host computer.
(See the "Keyboard Set-Up Screen" section in Chapter 4.)
Fll
(ESC)

F11
(ESC)

F11 is normally a function key used by application programs. In VT100 and
VT52 modes, it sends an ESC (escape) character.

CONTROLS, INDICATORS, AND CONNECTORS

F12
(BS)

F12
(8S)

F12 is normally a function key used by application programs. In VT100 and
VT52 modes, it sends a BS (backspace) character.
F13
(LF)

F13
(LF)

F13 is normally a function key used by application programs. In VT100 and
VT52 modes, it sends an LF (line feed) character.

Function Key Summary
The following keys are function keys used by application programs. Each key
takes on a meaning defined by the particular application program. The meaning
of a key mayor may not correspond to the legend on the key. The following list
shows typical uses for each key. Actual use depends on the application.

Application-Defined Keys

Cursor Positioning Keys

(-)
(-»
(l)
(1)

F7
F8
F9
F10
F11 (ESC)
F12 (BS)
F13 (LF)
F14
Help

Do
F17
F18
F19
F20
PF1
PF2
PF3
PF4

Editing Keys
Find
Insert Here
Remove
Select
Prev Screen
Next Screen

CONTROLS, INDICATORS, AND CONNECTORS

VISUAL INDICATORS
The keyboard has four visual indicators showing the current terminal status .or
operation in progress.
Hold Screen Indicator
The Hold Screen indicator is on when the video monitor screen is frozen. See
the "Hold Screen" key description.
Lock Indicator
The Lock indicator comes on to indicate that the terminal will send uppercase
characters only. See the "Lock" key description.
Compose Indicator
The Compose indicator comes on to indicate you are performing a compose
sequence. (See the "Composing Characters" section in Chapter 3.)
Wait Indicator
The Wait indicator is on when the keyboard is prevented (locked) from sending
information. You can clear this locked condition by invoking the Clear Comm
feature from the Set-Up Directory screen (Chapter 4). See Chapter 5 for the
causes of the keyboard lock condition.
AUDIBLE INDICATORS
The keyboard can generate two sounds you select from the Keyboard Set-Up
screen (Chapter 4), a keyclick and a bell. You can use the bell as a margin bell,
warning bell, or both.
Keyclick
The keyclick sound occurs each time you press a key, with the following
exceptions.
• You press Shift or Ctrl. These keys do not make a keyclick, because they
do not send a character. They modify characters sent by other keys.
• When the Wait indicator is on; characters from the keyboard are lost.
• The keyclick set-up feature is off.

CONTROLS, INDICATORS, AND CONNECTORS

Bell
The bell tone sounds in each of the following cases.

• As part of the power-up self-test
• When the terminal receives a bell (BEL) character from the computer
• After a compose character error
• When the cursor approaches the right margin

OPERATING PROCEDURES

GENERAL

This chapter helps you to become familiar with some specific terminal functions and operating procedures. However, your main reference source is the
documentation for your application software.
PRINTING

The VT220 has a built-in serial printer interface that supports the following
optional Digital printers.
LA34/38
LA35/LA36
LA12
LA100
LA120
LA50
LQP02

OPERATING PROCEDURES

The VT220 printing functions operate in one of four modes selected from setup screens (Chapter 4).
Mode

Set-Up Screen

Normal (default)

Printer Set-Up

Auto print

Printer Set-Up

Printer controller

Printer Set-Up

Local controller

Set-Up Directory and
Printer Set-Up

These modes let the terminal perform several print operations selected from
the keyboard and/or the computer.
Normal Mode
Normal mode lets you select all local printing functions (such as Pr 1 n t Full
Pa 9 e) from the keyboard.
Auto Print Mode
Auto print mode prints the current display line when the cursor moves to the
nextline. The cursor moves to the next line when the terminal (1) receives a line
feed, form feed, or vertical tab code, or (2) automatically wraps the line. When
selected, Au toP r i n t Mo de appears on the status line in set-up. You can use
all keyboard printing functions (such as Pr i nt Full Psge) in auto print mode.
To invoke auto print mode, typeCtrl-Print Screen. To exit auto print mode, type
Ctrl-Print Screen again.
Printer Controller Mode
In printer controller mode, the host computer has direct control of the printer.
Characters received from the host computer go directly to the printer, and are
not displayed on the screen. (See Chapter 5.) When selected, Pr i n t e r
Controller Mode appears on the status line in set-up. You cannot
select this mode from the keyboard (except by entering set-up).
You cannot use local printing functions in printer controller mode. For example,
Print Full Page does not work.

OPERATING PROCEDURES

Local Controller Mode
Local controller mode is a special mode that lets you send information directly
from the keyboard to the printer. You may find this feature useful in setting up
certain printers for operation, without involving the host computer.

To select local controller mode, you must select two different set-up features.
1. Local- selected in the Set-Up Directory screen.
2. Printer Controller Mode - selected in the Printer Set-Up
screen.
When you select these two set-up features, the terminal is in local controller
mode.
OPTIONAL MODEM
An optional modem lets the VT220 communicate over a telephone line with a
remote host computer. The VT220 accepts compatible modems such as the
AT&T 103, 113, and 212 types, in addition to Digital's DF02 and DF03. (See
Appendix B, "Options, Documentation, and Supplies.") See Chapter 5 for more
information on communications.
COMPOSING CHARACTERS
You can use compose sequences to create characters that do not exist as
standard keys on your keyboard. To use a compose sequence, you press a
series of keys. There are two types of compose sequences: three-stroke
sequences and two-stroke sequences.

NOTE: The compose sequences you can use depend on the character set
mode selected (multinational or national). Table 3-1 lists the valid compose
sequences for multinational mode. Table 3-2 lists the valid compose
sequences for each keyboard in national mode. In national mode, the compose
sequences you can use depend on the keyboard selected.
You can use three-stroke sequences on all VT220 keyboards. First you press
the Compose Character key, then you press two standard keys whose characters form a valid compose sequence.

OPERATING PROCEDURES

You can use two-stroke sequences on all keyboards except the North American keyboard. Two-stroke sequences are faster than three-stroke sequences,
but are limited to sequences starting with the following nonspacing diacritical
marks: grave accent, acute accent, circumflex accent, tilde mark, diaeresis
mark (umlaut), and ring mark. Two-stroke sequences do not use the Compose
Character key. Instead, you enter a nonspacing diacritical mark first. Then
enter a standard character that forms a valid compose sequence with the
diacritical mark.
Diacritical marks are available on all but the North American keyboard. The
diacritical marks vary among the keyboards, depending on relative use. Also,
some keyboards have keys that contain both a standard character and a
diacritical mark.
As with standard keys, you select the character you want with the Shift and
Lock keys.
If you use a diacritical mark within a three-stroke sequence, the diacritical mark
is treated as its equivalent character.
Diacritical Mark

Equivalent Character

Diaresis (umlaut) mark
Acute accent
Grave accent
Circumflex accent
Tilde mark
Ring mark

Double quote ..
Apostrophe '
Single quote
Circumflex character. A
Tilde character ""
Asterisk * or degree 0
I

Tables 3-1 and 3-2 list all valid compose sequences for multinational and
national modes respectively. Depending on the keyboard, you can create characters in column 1 in one or more ways.
• With a standard key (if available on that keyboard)
• With a three-stroke compose sequence (always)
• With a two-stroke compose sequence (if the diacritical mark is available
on the keyboard)

OPERATING PROCEDURES

Using a Three-Stroke Compose Sequence
Create a three-stroke compose sequence as follows.
1. Find the character you want to create in column 1 of Table 3-1 or 3-2.
2. Press the Compose Character key. (The Compose indicator comes on,
indicating the terminal is in compose mode.)
3. Type the two characters in column 2 for the character you want to create.
For example, to create e with acute accent, press Compose Character, and
then type e and apostrophe; or press Compose Character, and then type
apostrophe and e.
When you complete a valid sequence, the Compos~ indicator turns off and the
composite character is sent to the application. If you use an invalid sequence,
the sequence is aborted and the bell sounds (if the warning bell is enabled in
the Keyboard Set-Up screen, Chapter 4).
NOTE:

Function keys abort a compose sequence without sounding the bell.

Using a Two-Stroke Compose Sequence
Create two-stroke compose sequence as follows.
NOTE: You can use two-stroke compose sequences on all keyboards except
the North American keyboard.
1. Find the character you want to create in column 1 of Table 3-1 or 3-2.
Verify in column 3 that the character can be created.
2. Press the key with the diacritical mark shown in column 3. (The Compose
indicator comes on, indicating the terminal is in compose mode.)
3. Type the second character shown in column 3.
For example, to create e with a grave accent on a Danish keyboard, press the
key that has the grave accent and then type e.

OPERATING PROCEDURES

When you complete a valid sequence, the Compose indicator turns off and the
Composite character is sent to the application. If you use a invalid sequence,
the sequence is aborted and the bell sounds (if the warning bell is enabled in .
the Keyboard Set-Up screen, Chapter 4).

NOTE:

Function keys abort a compose sequence without sounding the bell.

Aborting or Restarting a Compose Sequence

If you accidently enter compose mode (by pressing the Compose Character
key or a diacritical mark key), press the <:Kl (delete) key to immediately
terminate the compose sequence and exit compose mode. No character is
sent to the application.
If you press Compose Character during a compose sequence, a new threestroke sequence starts from that point. The previous sequence is aborted, with
no effect on the application.

OPERATING PROCEDURES

TERMINAL SET-UP

GENERAL
This chapter describes the VT220 set-up screens, and how to use them. These
screens let you examine or change terminal operating features such as transmit/receive speeds, type of cursor, and so on.
The VT220 stores many of its operating features in an NVR (nonvolatile RAM)
memory. NVR memory retains theses features even when power is shut off. In
addition to storing operator-selected features, the terminal retains the factorydefault settings. You can recall these default settings in set-up.
You can change all available set-up features from the keyboard. Some features
can be changed by the host computer as described in the VT220 Programmer
Reference Manual. (See Appendix B to order other documents).

TERMINAL SET-UP

MA·l016-B3

Figure 4-1

Set-Up Screens

USING SET-UP

The set-up state is based on selectable displays called set-up screens. You
can select any set-up screen from the Set-Up Directory screen displayed when
you enter set-up (Figure 4-1). Each set-up screen displays the features for that
set-up function and lets you change or keep those features.You can only
display one set-up screen at a time. You can enter the Set-Up Directory screen
from any other set-up screen.
SET-UP SCREENS

Each set-up screen occupies the bottom third of the monitor screen. (Current
screen data is temporarily invisible.) Incoming data is not lost if the host supports XOFF and that feature is enabled. (See the "Communications Set-Up
Screen" section in this chapter.) Each screen contains the following information (Figure 4-2).
Screen title
Terminal identifier
Firmware version number
Status line
Fields (action, parameter, text parameter)

TERMINAL SET-UP

TOP
16 LINES
OF DISPLAY
ARE BLANK

SCREEN
TITLE

TERMINAL
IDENTIFIER

VT220 V2.0

To Next Set Up

VT200 Mode, 7 Bit Controls

User Defined Keys Unlocked
Application Keypad

FIRMWARE
VERSION
NUMBER

\
General Set-Up

BOTTOM
BLINES
OF DISPLAY
CONTAIN
SET-UP
SCREEN

User Features Unlocked

Application Cursor Keys

\ ----------------------------------

R",I." Mod,

p",,,, No< R"dy

Mod,m' No DSR.

STATUS
LINE

Figure 4-2

Sample Set-Up Screen

Screen Title
The screen title identifies the current set-up screen. There are seven set-up
screens.
1. Set-Up Directory
2. Display Set-Up
3. General Set-Up
4. Communications Set-Up
5. Printer Set-Up
6. Keyboard Set-Up
7. Tab Set-Up
Terminal Identifier
The terminal identifier identifies the type of terminal you are using, in this case
a VT220.

TERMINAL SET-UP

Firmware Version Number

The firmware version number identifies the level of firmware the terminal is
usrng.
c~_

Status Line

The status line appears at the bottom of each set-up screen. This line shows
you the current status of the modem (if EIA Modem Control is selected), the
printer, and the terminal insert/replace mode. The status line is a reporting line
only; you cannot change the status line from the keyboard. Table 4-1 describes
the status line messages.

TERMINAL SET-UP

Fields

The fields on each screen are blocks of text describing current operating
characteristics. There are three types of fields.

1. Action Field
An action field has only one value. When you select an action field and
press the Enter key, the terminal performs the action.
For example, each screen has an action field that reads To D1 rec tory.
When you select this field and press Enter, the Set-Up Directory screen
replaces the current screen.

2. Parameter Field
A parameter field contains a feature that has two or more values. When
you select a parameter field and press Enter, the next value replaces the
current value.
For example, if you select the keyclick parameter field, it may have a value
of Keyc 1 i c k. Pressing Enter changes the field to 1'10 Keyc 1 i c k.

3. Text Parameter Field
A text parameter field lets you enter a value from the keyboard. You can
select a text parameter field as follows.
1. Use the arrow keys to move the field cursor to the text parameter field.
(See the following "Set-Up Controls and Cursor" section.)
2. Press Enter. The terminal prompts you to enter text on the status line
at the bottom of the screen, temporarily overwriting the status line.
3. Type the text you want entered as the new value. The value appears
next to the prompt.
4. Press Enter to enter the new value.
If you make a mistake, press the <:XJ (delete) key to erase the last
character entered. If you want to abort the entry without changing the
original value, press an arrow key to change the field selection. (See the
following "Set-Up Controls and Cursor" section.)

TERMINAL SET-UP

Set-Up Controls and Cursor
The VT220 uses a field cursor while in set-up. The field cursor appears as a
highlighted field (reverse video) that you can move from field to field with the
arrow keys.
Table 4-2 describes the keys used to enter and exit set-up, move the field
cursor, and change operating characteristics.

TERMINAL SET-UP

SET-UP EXAMPLE: CHANGING FEATURES

This section provides an example of changing the terminal operating
characteristics in set-up.
Suppose the terminal is currently set to display its text in 80 columns, and the
keyboard keys click each time you press them.
You decide to change these two operating characteristics so the terminal
displays 132 columns, and the keys do not click when pressed.
Use the following procedure to change these two operating characteristics in
set-up.
1. Press the Set-Up key. The terminal enters set-up and displays the Set-Up
Directory screen (Figure 4-3).
2. Note that the cursor is on the Dis play field.
3. Press the Enter key. The terminal replaces the Set-Up Directory screen
with the Display Set-Up screen (Figure 4-4).
4. Use the arrow keys to move the field cursor to the 80 Columns field.
5. Press Enter. The field changes from 80 Columns to 132 Columns,
indicating that the feature changed.
NOTE: Although many parameter changes are immediate (such as the column feature), some changes do not take effect until you exit set-up.

TERMINAL SET-UP

6. Use the arrow keys to move the field cursor to the To Directory field.
(You want to change another feature.)
7. Press Enter. The terminal replaces the Display Set-Up screen with the
Set-Up Directory screen.
8. Use the arrow keys to move the field cursor to the Keyboard field.
9. Press Enter. The terminal replaces the Set-Up Directory screen with the
Keyboard Set-Up screen (Figure 4-8).
10. Use the arrow keys to move the field cursor to the Keyc I i c k field.
11. Press Enter. The field changes from Keyc 1 i c k to No Keyc 1 i c k, indicating that the feature changed.
12. Press Set-Up to exit set-up and return to the operating mode (on-line or
local).
SET-UP SCREEN DESCRIPTIONS
The following sections describe the set-up screens and their features. When
you select the various set-up features you want to use, make sure to check off
the box beside the parameter value selected for that feature. This gives you a
record of the values selected, in case the settings are accidently changed or
lost. If repairs to the terminal are necessary, the technician needs this information to reset the set-up feature values.

Table 4-3 summarizes the set-up screens. The table lists the features available
on each screen.

TERMINAL SET-UP

SET-UP DIRECTORY SCREEN

The Set-Up Directory screen (Figure 4-3) appears immediately when you enter
set-up. This screen lets you access any other set-up screen. The Set-Up
Directory screen also contains fields you can use to select terminal operating
features.
Table 4-4 describes all fields on this screen.

VT220 V2.0

Set-Up Directory

, . . . 'i"'§iil P.iIii';; 'HIM P"''''' ..

........ p.... dM.iiiiii' '."g....,,611_ ..
,.m.8 . .
,.!bllmml
North American Keyboard

Replace Mode

Printer: None

Figure 4-3 Set-Up Directory Screen

Modem: DSR, Connected

TERMINAL SET-UP

DISPLAY SET-UP SCREEN
The Display Set-Up screen (Figure 4-4) lets you define monitor display
characteristics.
Table 4-5 describes all fields on this screen.

Display Set·Up
To Next Set Up

"ii'.,,18'•. EiiI!!"'.,,''''

Llqht Text, Dark Screen

Block Cursor Style

Replace Mode

Figure 4-4

.:!.i·""W-

VT220 V2.0
Inter prpt Control s

Printer: None

Display Set-Up Screen

Modem: DSR, Connected

TERMINAL SET-UP

GENERAL SET-UP SCREEN
The General Set-Up screen (Figure 4-5) lets you define a group of commonly
used general operating features.
Table 4-6 describes all fields on this screen.

General Set·Up
To Next Set Up

'••jl+,.,,;

Usel Defined Keys Unlocked

VT220 V2.0
VT200 Mode, 7 Bit Controls
Usel Featul es Unlocked

NUlllerlC Keypad

Norrnal Cursor Keys

Replace Mode

Printer: None

I VT220lD

'm".!!!!!,,'

,,".",,'

Modem: DSR, Connected

MA_,012_83

Figure 4-5

General Set-Up Screen

TERMINAL SET-UP

COMMUNICATIONS SET-UP SCREEN
The Communications Set-Up screen (Figure 4-6) lets you define the communications environment between the terminal and host.
Table 4-7 describes all fields on this screen.

'.M.'"
'ri"'·'·'

Communications Set-Up

VT220 V2.0
RecclvP

8 Bits, No Pailly

EIA Port, Ddta Leads Only

Replace Mode

Disconnect, 2 s DeidY

T!dnSllllt

,.e,. '.'",,"'.
LlflllterJ T,al1sl11ll

Printer: None

MA-1008-83

Figure 4-6 Communications Set-Up Screen

TERMINAL SET-UP

PRINTER SET-UP SCREEN

The Printer Set-Up screen (Figure 4-7) lets you define printer operations with
the VT220.
Table 4-8 describes all fields on this screen.

Printer Set-Up

'"" ••" '"·+,,141 1''4#,1':1,1,8
Normal Print Mode
Print Full Page
Replace Mode

Figure 4-7

VT220 V2.0

8 B Its, No Parity
Pnnt National Only
Printer: None

Printer Set-Up Screen

I,dijhnu".

TERMINAL SET-UP

KEYBOARD SET-UP SCREEN
The Keyboard Set-Up screen (Figure 4-8) lets you define keyboard operating
features.
Table 4-9 describes all fields on this screen.

Keyboard Set-Up
To Next Set Up

••••,.iN Typewriter Keys

Auto Repeat
No Auto Answerback
Replace Mode

Figure 4-8

Margin Bell
Answerback~

Printer: None

Keyboard Set-Up Screen

VT220 V2.0

'fiilliili,F:A1M _

'P·...i@i!lt"

TERMINAL SET-UP

TAB SET-UP SCREEN

The Tab Set-Up screen (Figure 4-9) lets you set the terminal's tab stop
settings.
Table 4-10 describes all fields on this screen.
The tab stop fields are one character wide. A ruler appears below the tab stop
fields on the screen. Refer to the ruler when setting tabs.
There is one tab stop field for each column on the screen display. The display
can be 80 or 132 columns wide, depending on the number of columns set. (See
Co 1umn 5 in the Display Set-Up screen.)
There are two possible settings for each tab stop field: the letter T (tab stop
set) or blank (no tab stop set).
You can move the field cursor to a tab stop field with the arrow keys or the Tab
key. After you select a field, press the Enter key to place a T in a blank field or
erase a T from that field.

VT220 V2.0
Tab Set-Up

'P'•••" 'p.+1'.,,1

'''Will,.

1234567890

Replace Mode

Figure 4-9

Tab Set-Up Screen

Printer: None

Set 8 Column Tabs

TERMINAL SET-UP

COMMUNICATION

GENERAL

This chapter describes how the VT220 communicates with a host computer
and a printer.
The terminal operates on full-duplex asynchronous lines only, and has ten
possible transmit/receive speeds. You select the transmit/receive speeds in
set-up for both the terminal (Communications Set-Up screen) and the printer
(Printer Set-Up screen).
The VT220 operates in accordance with the following national and international
communications standards.
EIA Standard RS232C/RS423
CCITT V.24
CCITT V.26 (V.10)
CCITT X.20 (V.21)
You can connect the terminal directly to a local host computer with a cable. You
can also connect the terminal indirectly to a remote host computer through
public-switched or dedicated telephone lines, using a modem or acoustic
coupler.

COMMUNICATION

HOST AND PRINTER PORT INTERFACES

The VT220 has two asynchronous serial ports. One port is for communication
with a host computer, and the other is for communication with a printer.
There are two host port connectors.
• A 25-pin subminiature D-type (EIA RS232C/RS423) connector that connects the terminal to a local or remote host computer
• An a-pin EIA Mate-N-Lok (20 mA) connector that connects the terminal to
a local host computer
The printer port has one connector.
• A 9-pin subminiature D-type (EIA RS232C/RS423) connector that connects the terminal to a local printer.
Tables 5-1 through 5-3 describe the interface signals for the three connectors.
NOTE:

Only the connector pins listed in Tables 5-1 through 5-3 are used.

MODEMS

The VT220 can operate with all modems conforming to the national and international standards listed at the beginning of this chapter. However, the modem
at the terminal must be compatible with the modem at the host computer.
The VT220 accepts compatible modems and acoustic couplers such as the
AT&T 103,113, and 212 types, in addition to Digital's DF02 and DF03.
The terminal must be certified for connection to non-AT&T type modems used
outside of continental North America. Your local Digital Field Service office has
detailed information on terminal certification and use of non-AT&T type
modems.

COMMUNICATION

CABLES
Figure 5-1 shows the RS232C/RS423 cables you can use to connect the
terminal to a host computer and printer.

25·PIN EIA HOST PORT
TERMINAL

NULL MODEM CABLE

BCC22D-1O 110 feet)
-25 125 feet)
-50 150 feet)

HOST
COMPUTER

20rnA PORT
TERMINAL

20 rnA CABLE

i-J

HOST
COMPUTER

BC05F-15 115 feet)
-50150 feetl

20 rnA PORT
TERMINAL

i-J

20 rnA EXTENSION

20 rnA CABLE

BC05X-15 115 feet)
-50 150 feet)

BC05F-15 115 feet)
-50 150 feet)

HOST
COMPUTER

25-PIN EIA HOST PORT
MODEM CABLE

TERMINAL

BCC04-10 110 feet)
-25 125 feet)
-50 150 feet)

MODEM

HOST
COMPUTER

9 PIN PRINTER PORT

i-J

PRINTER CABLE

PRINTER

BCC05-10 110 feet)
-25 125 feet)
-50 150 feet)
MA·l014-83

Figure 5-1

Cables

COMMUNICATION

PRINTERS

You can connect the terminal to a local asynchronous serial printer by using a
null modem cable. Here are some of the Digital printers you can use with the
VT220.
LA12
LA34
LA35
LA36
LA38

LA50
LA100
LA120
LQP02

CHARACTER FORMAT

The terminal sends and receives characters in serial format. You select the
character format (Figure 5-2) in set-up.
NOTE:
X3.1S.

Detailed information on character format is available in ANSI Standard

START BITOF
NEW CHARACTER
10R2
BITS

~~E OF

INE

SPACE +
MARK -

70RS
DATA BITS

.,.

L~B I

_ ... -

.,.

02 I 03

.J. -

START
BIT

Figure 5-2

Character Format

...

... - . . .

'T -

I 04 I 05 I 06 I ~;B I

~r---ST10P I ST20P

i.=-.t - .J. - ... -7 .J. ".L.....;..-L-oTJ

ONE BIT
TIME=
ONE/
BAUD RATE

OPTIONAL
8TH BIT

OPTIONAL
PARITY
BIT

RETURN TO IOLE
STATE OF LINE

COMMUNICATION

TERMINAL - HOST DATA FLOW CONTROL
The terminal stores incoming characters in a character input buffer and
processes the characters on a first-in/first-out basis. The size of the input
buffer is 254 characters. When the input buffer fills to 64 or 128 characters
(selected from the Communications Set-Up screen), the terminal sends an
XOFF character (if you enabled XOFF from the Communications Set-Up
screen) to stop the host computer from sending more characters. If the computer fails to respond to the XOFF character, the terminal sends a second
XOFF character when the input buffer fills to 220 characters. The terminal
sends a third XOFF character when the buffer is full.

When the input buffer contents falls below 32 characters, the terminal sends an
XON character to tell the host computer to start sending characters again.
NOTE: If you disable XOFF in set-up, the terminal does not send XOFF to the
host computer when the input buffer fills. The Hold Screen key is a/so disabled.
With XOFF disabled, there is no way to ensure that data will not be lost.
If you enable XON/XOFF, the terminal recognizes received XON and XOFF
characters. When the terminal receives XOFF, it stops sending data (except
XON/XOFF characters). If the keyboard data buffer overflows, the keyboard
locks and the Wait indicator turns on. The terminal resumes transmission when
it receives an XON.
Conditions That Send XON
When you enable the XOFF/XON feature in set-up, the following conditions
send XON.

• The number of characters in the input buffer reaches the XON pOint (32
characters) and the last flow control character sent was XOFF.
• A clear comm operation is performed.
• A recall operation is performed.
• The power self-test is completed (Chapter 6).
• You press the Hold Screen key to release the screen when the input
buffer is at or below the XON point.

COMMUNICATION

Conditions That Send XOFF

When you enable the XOFF /XON feature in set-up, the following conditions
send XOFF.
• The number of characters in the input buffer reaches the first XOFF point
(64 or 128 characters, selected from the Communications Set-Up screen)
for the first time since the last XON was sent.
• The number of characters in the input buffer reaches the second XOFF
point (220 characters) for the first time since the last XON was sent.
• The terminal receives a character when the input buffer is full (256
characters).
Buffer Overflow Prevention

If the host computer does not respond to the XOFF from the terminal, the input
buffer continues to fill with characters. If the buffer is filled and characters are
still coming, the buffer overflows and characters are lost. In place of lost
characters, the terminal displays reverse question mark characters ( ~ ).
You can use the following formulas to determine how fast the host computer
must respond to the first XOFF character, to prevent loss of characters due to
buffer overflow. Calculate the overflow first, then host response time.
NOTE: These formulas assume that you set the transmit rate limit feature in
the Communications Set-Up screen to Un 1 i mit e d.
1. Overflow
OVFL = (MXBF - XOFF) - [3 x(RCDR/XMDR)] - (RCDR/600)
where:
OVFL = the number of characters to overflow
MXBF = the receive buffer size (254 characters)
XOFF = the first XOFF point (64 or 128)
RCDR = the received data rate (receive speed)
XMDR = the transmitted data rate (transmit speed)

COMMUNICATION

2. Host Response Time
HRST = OVFL x [(DATA + STOP + PRTY + 1)/RCDR]
where:
HRST = the host computer response time (in seconds)
OVFL = the number of characters to overflow
DATA = the number of data bits per character
STOP = the number of stop bits per character
PRTY = the number of parity bits per character
Example
The VT220 sends and receives 8-bit characters with no parity at 4800 bits per
second. There is 1 stop bit. XOFF is sent when the buffer has 64 characters in
it.
OVFL = (254 - 64) - [3 x (4800/4800)] - (4800/600)
= 179 characters
HRST = 179 x [(8 bits + 1 bit + 0 bits + 1)/4800]
= 0.37 seconds
Therefore, the host computer must stop sending data in 0.37 seconds, or the
terminal input buffer will overflow.
Use of Fill Characters

Software that does not support XON/XOFF characters from the terminal can
still use all terminal features by using fill characters. In some applications, you
can use the terminal without XON/XOFF support or fill characters. However,
the bit rate must be limited to 9600. And the software must not send the ESC
(escape) code, or use slow scrolling, split screen, or the printer port.

COMMUNICATION

Connect/Disconnect
When a connection is made to the host computer via a modem, the terminal
performs the following operations to ensure it is ready to send and receive.

•
•
•
•
•

Unlocks the keyboard (if it was locked).
Clears any transmit in progress.
Clears the keyboard buffer and all message buffers.
Clears the input buffer.
Clears XOFF sent and XOFF received.

The following conditions cause a communications line disconnect.
• Typing Shift-Break
• Invoking Recall or Defaul t values in the Set-Up Directory screen
• Loss of DSR
• Loss of RLSD for a time you defined in set-up
• No RLSD within 30 seconds after DSR
• A self-test command received from the host computer
• Switching from the EIA port to the 20 mA port, or from the 20 mA port to
the EIA port
The usual way to disconnect the terminal from the communications line at the
end of communications is to type Shift-Break. The host computer's response
to the disconnect signal depends on the computer and the software.
TERMINAL-PRINTER DATA FLOW CONTROL
The VT220 sends only data characters to the printer; the terminal does not
send XON/XOFF. The terminal recognizes only XON/XOFF from the printer
(any other characters from the printer are ignored).

When the terminal receives XOFF from the printer, the terminal stops sending
data. The terminal starts sending data again when it receives an XON, or when
a clear comm operation is performed.
Note on Printer Installation
Using an a-bit setting for the printer port line implies the use of a-bit C1 control
characters. Using a 7-bit setting implies the use of the 7-bit ESC [ form of C1
control characters.

NOTE: Older printers may not recognize the 8-bit form of C1 control characters. With these printers, you must set the printer line to 7-bits for correct
operation.

PROBLEM SOLVING

GENERAL

This chapter describes what to do if you have a problem with the VT220. The
chapter provides a problem checklist and describes the power-up self-test.
COMMON OPERATING PROBLEMS

Table 6-1 lists common operating problems and their possible solutions. Check
this list before calling for service.

PROBLEM SOLVING

POWER-UP SELF-TEST

The power-up self-test runs automatically each time you power up the terminal.
During the test cycle, the power-up self-test has full control of the the terminal.
The terminal cannot respond to commands other than those used for the test
itself. When the test cycle ends, control returns to the terminal.
In the self-test mode, the monitor screen and the keyboard indicators (Hold
Screen, Lock, Compose, and Wait) provide information about the terminal
operating status. The monitor screen displays a text message, and the keyboard indicators provide a coded message.
PERFORMING THE POWER-UP SELF-TEST

Start the power-up self-test by setting the terminal power switch to 1 (on).
During the self-test the following events should occur .
• All keyboard indicators turn on and off .
• The bell tone sounds.
A successful power-up Self-test ends with all keyboard indicators off and the
screen displaying the message shown in Figure 6-1. The message is erased
when a character is received from the host computer, or when you press any
key.
The terminal displays an error message on the screen (if possible) if the test
finds any error. Table 6-2 explains the error messages displayed on the
screen.

/'
"-

IVT220 OKI
j ...l nuol

Figure 6-1

•
MA·1013--83

Successful Power-Up
Screen Message

PROBLEM SOLVING

DIGITAL SERVICE

If the self-test indicates a problem, call your local Digital Field Service number
for assistance. Before calling, make sure to note the exact nature of the
problem, when it occurred, and any error messages or codes that appeared.
Information about your warranty, Digital services, terminal supplies, and spare
parts is provided on the inside of the back cover of this manual.

SPECIFICATIONS

GENERAL

This appendix lists the specifications of the VT220 video terminal.
VT220 SPECIFICATIONS
Physical

Terminal
Height
Width
Depth
Weight

28.3 em (11-1/8 in)
33.3 em (13-1/8 in)
38.7 em (15-1/4 in)
11.8 kg (26 Ibs)

Adjustable tilt

+5 to -15 degrees

Keyboard
Height
Width
Depth
Weight

5.1 em (2 in)
53.3 em (21 in)
17.1 em (6.75 in)
2 kg (4.5 Ibs)

APPENDIX A

Environmental

Operating
Temperature
Relative humidity
Maximum wet bulb
Minimum dew point
Maximum altitude

10° to 40°C
(50° to 104°F)
10% to 90%
28°C (82°F)
2°C (36°F)
2.4 km (8000 ft)

Storage
Temperature
Relative humidity
Maximum altitude

-40° to 66°C
(-40° to 151°F)
0% to 95%
9.1 km (30,000 ft)

Electrical

Line voltage
(switch selectable)

90 to 128 Vac
(100 to 120 RMS nominal)
single-phase, 3-wire
180 to 268 Vac
(220 to 240 RMS nominal)
single phase, 3-wire

Line frequency

47 to 63 Hz

Line current

0.48 amps RMS at 120 Vac RMS
0.24 amps RMS at 240 Vac RMS

Input power

60 watts maximum

Power cord

Detachable, 3-conductor, grounded

Power cord receptacle

EIA specified CEE22-6A

APPENDIX A

Display

30.5 cm (12 in) diagonal measure
monochrome

CRT

Active display size
Horizontal
Vertical

20.3 cm (8 in)
12.7 cm (5 in)

Format

24 lines of 80 or 132 characters

Character

7 x 9 dot matrix with 2 descenders

Character size
80 column mode
132 column mode

3.35 x 2.0 mm (0.132 x 0.078 in)
3.35 x 1.3 mm (0.132 x 0.051 in)

Character sets

ASCII, national replacement (NRC),
DEC special graphic, and DEC
supplemental character sets
(each 94 characters)

Video attributes

Reverse video, underline, bold, and
blinking - selected individually
or in any combination

Cursor type

Blinking block cursor or
blinking underline cursor

APPENDIX A

Keyboard

General

1OS-key detachable unit with a
1.8 m (6 ft) coiled cord with
a 4-pin telephone-type modular
connector.
Word processing and data processing
versions available in 15 languages

Keypad

Sculptured key array. Matte texture
finish keys. Home-row key height
30 mm (1.18 in) above desk top

Key size

12.7 mm (0.5 in) square

Key spacing

19 mm (0.75 in) center-to-center
(single-width keys)

Numeric keypad

18 keys

Function keys

36 keys, firmware and software
driven

Visual indicators

4 LED indicators: Hold, Lock, Wait,
and Compose

Audible signals
Keyclick

Sounds after each keystroke

Bell

Sounds when BEL character is
received, when approaching
right margin, and when compose
errors occur.

Multiple bell

Sounds on error in a set-up save or
recall operation.

OPTIONS, DOCUMENTATION,
AND SUPPLIES

GENERAL

This appendix describes the options, documentation, and supplies offered by
Digital for the VT220. Part numbers and ordering information are included.
AVAILABLE OPTIONS
Modems

There are two modem options available for the VT220. You can order these
options from Digital.
Part Number

Description

DF02-M

Direct-connect, AT&T 103J equivalent, 300 baud, full-duplex
Modern with EIA RS232C interface

DF03-M

Direct-connect, AT&T 103J/212A equivalent, 300/1200
baud full-duplex modem with EIA RS232C interface.

Cables

See Chapter 5 for information on available modem and printer cables.

APPENDIX B