Digital Equipment VT100 User manual

EK-VT1OO-U G-002

1st Edition, August 1978
2nd Edition, January 1979
Copyright © 1978, 1979 by
Digital Equipment Corporation
The material in this manual is for informational
purposes and is subject to change without notice.
Digital Equipment Corporation assumes no re-
sponsibility for any errors which may appear in
this manual.
Printed in U.S.A.
This document was set on DIGITAL's DECset-
8000 computerized typesetting system.
The following are trademarks of Digital Equip-
ment Corporation, Maynard, Massachusetts:
DIGITAL
DEC
PDP
DECUS
UNIBUS
DECsystem-1 a
DECSYSTEM-20
DIBOL
EDUSYSTEM
VAX
VMS
MASSBUS
OMNIBUS
OS/8
RSTS
RSX
lAS

CONTENTS
INTRODUCTION
CHAPTER 1OPERATOR
INFORMATION
PART 1 - KEYBOARD CONTROLS AND INDiCATORS 4
Monitor Controls " 7
Audible Indicators (Tones) 7
PART 2 - SET-UP MODE 8
SET -U PFeatures at aGlance 8
Determining
What aSET-UP Feature Does 10
How To Change aSET-UP Feature 11
Setting the Answerback Message 12
Saving the SET-UP Features 12
Recalling SET -UPFeatures , 12
Resetting the Terminal "" .. ,13
PART 3 - DEFINITION
OF EACH SET-UP FEATURE 13
PART 4 - SELF-TESTING THE VT1 00 16
Self-Test Error Codes 17
PART 5 -
WHAT TO DO IN THE EVENT OF APROBLEM 18
CHAPTER 2
INSTALLATION, INTERFACE INFORMATION AND SPECIFICATIONS
instaliation .. " 21
Site Considerations 21
Unpacking and Installation " 21
User Maintenance 24
Interface Information 24
EIA Interface 24
Optional 20 mA Current Loop Interface 26
External Video Connections 27
VT 100 Specifications , , 28
How to Order Hardware Documentation 30
CHAPTER 3 PROGRAMMER SECTION
The Keyboard 34
Communications Protocols 40
Terminal Control Commands ~ 42
Control Characters 42
Control Sequences 43
Valid ANSI Mode Control Sequences 43
CPR Cursor Position Report - VT100 to Host .45
CUB Cursor Backward -Host to VT100 and VT100 to Host
45
CUD Cursor Down -Host to VT100 and VT100 to Host """.. . .. A5
CUF Cursor Forward -Host to VT100 and VT100 to Host 45
CUP Cursor Position 45
CUU Cursor Up -Host to VT100 and VT100 to Host 46
DA Device Attributes 46
DECALN Screen Alignment Display (DEC Private) 46
DECANM ANSI/VT52 Mode (DEC Private) .46
DECARM
Auto Repeat Mode (DEC Private) .47
DECAWM Autowrap Mode
(DEC Private) 47
DECCKM Cursor Keys Mode (DEC Private) 47

DECCOLM Column Mode (DEC Private) .47
DECDHL Double-Height Line (DEC Private) .47
DECDWL Double-Width Line (DEC Private) 47
DEClO Identify Terminal (DEC Private) .48
DECINLM Interlace Mode (DEC Private) 48
DECKPAM Keypad Application Mode (DEC Private) .48
DECKPNM Keypad Numeric Mode (DEC Private) 48
DECLL Load LEOS (DEC Private) .48
DECOM Origin Mode (DEC Private) 48
DECRC Restore Cursor (DEC Private) .49
DECREPTPARM Report Terminal Parameters .49
DECREQTPARM Request Terminal Parameters 49
DECSC Save Cursor (DEC Private) 50
DECSCLM Scrolling Mode (DEC Private) 50
DECSCNM Screen Mode (DEC Private) 50
DECSTBM Set Top and Bottom Margins (DEC Private) 50
DECSWL Single-Width Line (DEC Private) 51
DECTST Invoke Confidence Test. 51
DSR Device Status Report 51
ED Erase In Display 52
EL Erase In Line 52
HTS Horizontal Tabulation Set 52
HVP Horizontal and Vertical Position 52
IND Index 53
LNM Line Feed/New Line Mode 53
NEL Next Line 53
RI Reverse Index 53
RIS Reset To Initial State 53
RM Reset Mode 53
SCS Select Character Set 54
SGR Select Graphic Rendition 54
SM Set Mode 54
TBC Tabulation Clear 55
Modes 55
ANSI Specified Modes 55
DEC Private Modes 55
Valid VT52 Mode Control Sequences 56
Cursor Up 56
Cursor Down 56
Cursor Right 56
Cursor Left. 56
Enter Graphics Mode 56
Exit Graphics Mode 57
Cursor to Home 57
Reverse Line Feed 57
Erase to End of Screen 57
Erase to End of Line 57
Direct Cursor Address 57
Identify 57
Enter Alternate Keypad Mode 57
Exit Alternate Keypad Mode 58
Enter ANSI Mode 58
Control Sequence Summary 58

ANSi Compatibie Mode 58
VT52 Compatible Mode 61
CHAPTER 4
VT100 OPTIONS
Advanced Video Option - VT1 XX-AB 65
Advanced Video Option Installation 66
Advanced Video Option Checkout 66
20 mA Current Loop Option - VT1 XX-AA 68
20 mA Current Loop Option Installation 68
20 mA Current Loop Option Checkout 69
Communications Cables 70
APPENDIXA
APPENDIX B
APPENDIX C
ANSI DEFINITIONS AND NOTATION 73
7-BIT ASCII CODE 77
FILL CHARACTER REQUiREMENTS 79
OTHER TERMINAlS 80
FIGURES
1-1 VT1 00 Terminal................................................................................................ . 2
1-2 VT100 Keyboard , , .. , , .. , 4
1-3 VT100 Terminal (Rear View) 7
1-4 SET-UP AMode Presentation 8
1-5 SET-U P B Mode Presentation 9
1-6 SET -U P B Mode Summary , 9
2-1 VT100 Terminal Dimensions 22
2-2 VT100 Rear View 23
2-3 20 mA Current Loop Interface 26
2-4 Composite Video Output 28
3-1 Terminal Data Flow 33
3-2 VT1 00 Keyboard 34
4-1 VT100 Rear View 67
4-2 Advanced Video Option Installation 67
4-3 20 mA Current Loop Option 68
4-4 Terminal Controller Board 69
TABLES
1-1 Categories of SET-UP Features 10
1-2 SET-UP Feature Change Summary , 11
1-3 Nonfatal Displayed Error Codes 17
1-4 Problem Checklist 18
2-1 EIA RS-232-C Connector Signals 24
3-1 Machine States , , , 35
3-2 Alphabetic Key Codes , .. , .. , 35
3-3 Nonalphabetic Key Codes 36
3-4 Function Key Codes 36
3-5 Control Codes Generated 37
3-6 Cursor Control Key Codes 38

3-7 VT52 Mode Auxiliary Keypad Codes 38
3-8 ANSI Mode Auxiliary Keypad Codes 39
3-9 Special Graphics Characters 39
3-10 Control Characters 42
4-1 Available Communications Cables 70
C-1 Fill Character Requirements 79
Installation, Warranty and Service Information on Inside Back Cover

INTRODUCTION
The VT100 terminal is designed to work very much like atypewriter. This guide
will tell you everything you need to know to use your terminal.
Achecklist label
is provided for making asemi-permanent record of the features.
unique functions. and mode
of operation of your terminal. Place this label under
the keyboard and keep
it up-to-date so that you will have aquick reference to the
basic status
of your machine.

CHAPTER 1
OPERATOR INFORMATION
The VT100 is asimple device to operate. The terminal (Figure 1-1) is basically a
typewriter
that uses avideo screen instead of paper and communicates with a
computer.
If you can operate atypewriter, you can operate aVT100.
Chapter 1
is divided into five parts:
1. Controls and Indicators
2. Setup Mode
3. Definition
of Each Setup Feature
4. Self-Testing the
VT 100
5. What to do in the Event of aProblem
Part 1shows all the controls and indicators on the terminal and summarizes
the function
of each, thus providing aquick reference for these functions.
Part 2defines the SET-UP mode and briefly summarizes its features.
Part 3describes each feature
in detail. Refer to this section if you need
further information on afeature mentioned in the SET-UP Summary provided
in Part 2.
Part 4provides information on self-testing the VT100. It outlines the steps
required
to start the built-in self-tests and how to interpret the results once
the tests have been run.
Part 5provides aprocedure
to follow in case you encounter any problem
with the VT100. Easily recognized failures with simple corrective actions are
provided for each symptom. Check the list on page
18 before calling for
service.
3

Figure 1-1
VT100 Terminal

4OPERATOR INFORMATION
PART 1
KEYBOARD CONTROLS
AND INDICATORS
The VT100 terminal normally performs a two-part function. It is an input device to
acomputer -information entered through the keyboard is sent to the computer. It
is simultaneously an output device for the computer - that is. data coming in from
the computer is displayed on the video screen. The following controls and in-
dicators on the VT100 keyboard are illustrated in Figure 1-2 .
Figure 1-2 VT100 Keyboard
••••
••••
••••
···1
...
•SETUP
This key is used in conjunction with other keys to perform specific functions such
as setting tabs. scrolling. and altering terminal characteristics.
ON LINE
This indicator lights to show that the VT100 is on-line and ready to transmit or
receive messages.
LOCAL
This indicator lights to show that the terminal is off-line and cannot communicate
with the host device. In local mode the keyboard remains active and all characters
typed are placed on the screen.
KEYBOARD LOCKED
This indicator lights to show that the keyboard has been turned off. The VT100 is
still able to receive data from the host. This condition can be cleared by entering
and exiting SET-UP mode.
L1-L4
These indicators are turned on and off by the host. Consult your local operating
procedures for the meaning of each indicator. L 1-L4 are also used to show self-
test errors.
••••
Each of these keys causes the VT100 to transmit acode which has aspecial
meaning to your system. Consult your local operating procedures for the meaning
of these keys. In SET-UP mode the aand akeys increase or decrease the
brightness of the display. The aand akeys move the cursor left and right.
•BACKSPACE
This key transmits abackspace code.

•BREAK
This key transmits abreak signal.
•••• PF1-PF4
Each of these keys causes the VT100 to transmit acode which has aspecial
meaning to your system. Consult your local operating procedures for the meanings
of these keys.
Numeric Keypad
The numeric keypad enables numbers to be entered in calculator fashion. Each key
in the numeric keypad generates the same character as the corresponding numeric
key on the main keyboard. The ENTER key corresponds to the RETURN key.
These keys may also be interpreted by the host computer as special function keys.
Consult your local operating procedures for the meanings of these keys.
•DELETE
This key causes the VT100 to transmit adelete character code to the host system.
The deleted character mayor may not be erased from the screen.
•RETURN
This key transmits either acarriage return (CR) code or acarriage return (CR) and
linefeed (LFj code. This is aSET-UP selectable feature.
•L1NEFEED
This key transmits alinefeed code.
_ SHIFT
When pressed, this key enables the uppercase function of all keys. If akey does
not have an uppercase function the SHI FT key will be disregarded.
II RESET
When the terminal is in SET-UP mode. this key starts the reset sequence. This has
the same result as turning the terminal power off and then on.
II 80/132 COLUMNS
When the terminal is in SET-UP Amode. this key switches the display line size
from 80 to 132 characters per line or from 132 to 80 characters per line.
II RECEIVE SPEED
When the terminal is in SET-UP Bmode. this key steps the terminal through the
receive baud rate settings in ascending order.
• TRANSMIT SPEED
When the terminal is in SET-UP Bmode, this key steps the terminal through the
transmit baud rate settings in ascending order.
•TOGGLE 1/0
When the terminal is in SET-UP Bmode. this key turns the selected operational
feature on or off.
OPERATOR INFORMATION 5

6OPERATOR INFORMATION
••••
••••
••••
···1
...
Figure 1-2 VT100 Keyboard
(cant)
II BELL G
When pressed in combination with the CTRL key. this key causes abell code to be
sent to the host.
II SET-UP A/B
When the terminal is in SET-UP mode. this key switches the terminal from SET-UP
A to SET-UP 8or from SET-UP 8 to SET-UP A.
• LINE/LOCAL
In SET-UP mode. this key alternately places the VT100 ON LINE or LOCAL to your
system. When it is ON LINE. the VT100 communicates with your system. When it
is in LOCAL the VT100 is electrically disconnected from your system.
II CLEAR ALL TABS
In SET-UP A. this key clears all horizontal tabs set in the VT100.
• SET/CLEAR TAB
In SET-UP A. this key sets or clears individual horizontal tabs.
__ CAPS LOCK
This key enables the transmission of uppercase alphabetic characters only. All
numeric and special symbol keys remain in lowercase.
• NO SCROLL
When first pressed. this key stops the transmission of data from the computer to
the VT100. When pressed asecond time. transmission resumes from where it was
stopped. Check your local operating procedures to ensure that your system recog-
nizes this key.
•CTRL
When pressed in combination with another key. the CTRL key causes the VT100
to transmit acode which has aspecial meaning to your system.
• TAB
This key transmits atab code.
•ESC
This key transmits acode which normally has aspecial meaning to your system. In
many applications. it tells your system to treat the next keys pressed as acom-
mand.

MONITOR CONTROLS
The VT100 monitor contains only two controls: the power switch and the power
selector switch.
which is used to adapt the terminal to the available ac input
voltage range (see specifications).
Audible Indicators (Tones)
There are three audible alarms associated
with the VT100: ashort tone (click). a
long tone (bell). and aseries
of long tones.
Short Tone (Click) -The short tone is sounded by the terminal whenever akey is
pressed.
with the following exceptions:
•
SHIFT or CTRL keys do not generate any keyclick because these keys do
not transmit any codes but only modify the codes transmitted by other
keys.
•KBD LOCKED indicator is turned on; in which case. the characters typed
are lost.
•The keyclick feature has been turned
off in SET-UPmode.
Long
Tone (Bell) -The long tone is sounded by the terminal to indicate one of the
following conditions:
• A bell code was received from the computer.
•The cursor is eight characters away from the right margin and the margin
bell feature is enabled.
Series
of Long Tones -The terminal will sound the long tone several times in
rapid succession
to indicate that the nonvolatile memory (NVR) had difficulty in
reading or
writing the SET-UP features. (When this occurs. check the SET-UP
features and then perform the Recall or Save operation again.)
OPERATOR INFORMATION 7
CAPTIVE
SCREWS (4) ACCESS
COVER
KEYBOARD
~ OPTIONAL 20mA
CONNECTOR COMMUNiCATiON
CONNECTOR
POWER
SELECTOR
SWITCH
EIA
COMMUNICATIONS
CONNECTOR
EXTERNAL VIDEO
INPUT CONNECTOR
EXTERNAL VIDEO
OUTPUT CONNECTOR
MAIN FUSE
POWER SWITCH
MODEL +SERIAL
NUMBER LABEL
MA-1987
Figure 1-3
VT1 00 Terminal
(Rear View)

8OPERATOR INFORMATION
PART 2
SET-UP MODE
Figure 1-4
SET-UP AMode Presentation
Unlike most terminals. the VT100 does not use switches or jumpers to individually
turn the built-in terminal features on or off. Instead. the VT100 uses anonvolatile
memory (NVR) which always remembers what features have been selected. as if a
switch had been set.
The selection and storage of built-in terminal features is performed in aspecial
mode of operation called SET-UP mode. When you enter SET-UP mode. the status
of the features stored in the temporary memory is shown on the screen. You can
then change the features and store any new feature selections either temporarily.
by leaving SET-UP mode; or on afixed basis. by performing aSave operation. In
either case. the terminal operation will reflect the new feature selection. If arecall
operation is performed. or the terminal is reset. or the terminal power is turned
OFF. all temporary feature settings are replaced by the features that have been
stored on afixed basis.
SET-UP Features at a Glance
When entered. SET-UP mode provides two brief summaries of the current feature
status. The first presentation -SET-UP A - displays the location of the tab stops
set in the terminal and avisual ruler which numbers each character position on the
line. The second presentation -SET-UP B - summarizes the status of the other
terminal features.
SET-UP A - To enter SET-UP A. press the SET-UP key. The display will now have
apresentation similar to Figure 1-4. The bottom line of the display consists of a
"ruler" which numbers each character position available on aline. The location of
each tab stop is shown by a "T" placed above the ruler. If the tab stop(s) set are
those desired. you may exit SET-UP mode by pressing the SET-UP key again or
you may now change the tabs to meet your requirements.
SET-UP A
TO EXIT PRESS ·SET-Up·

OPERATOR INFORMATION 9
SET-UP B-SET-UP Bmode may only be entered from SET-UP Amode. To enter
SET-UP Bfrom SET-UP A, press the 5key on the main keyboard. The display
will
then look like Figure 1-5.
Figure 1-6 summarizes the SET-UP Bpresentation. This summary allows you to
quickly determine what features are enabled. For additional information on afea-
ture refer to the Definition
of Each Feature section.
To exit SET-UP Bpress the
SET-UP key.
SET-UP B
I
I
l~
I
I
~,J
----
MA2733
Figure 1-5
SET-UP BMode Presentation
(OPTIONAL
DISPLAY
FOR CUSTOM
FUNCTIONS)
~~ ::::::::: TSPEED c::::=J
SCROLL [0 = JUMP r--1II(SHIFTEDl {a, =_ :
~ l, =SMOOTH I" <
IAUTOREPEAT (0 = OFF WRAP AROUND [0 = OF.F
II r- t1 = ON._ Ii L1 = ON
ISCREEN {a =DARK BACKGROUND I! NEW LINE {a =OFF
II ~ =LIGHT BACKGROUND II I \.., = ON
illr
·iCURSOR
JO =UNDERLINE illrl.· IINTERLACE {a =OFF
I ' L.' =BLOCK I1= ON
, 2~ 3 4~
III L· 1111-
I II AUTO XON XOFF (0 :OFF I I I LPOWER {a =: 60 Hz
II I 1,..1 ON I I I 1 - 50 Hz
I
·L
ANSIIVT52 {a =VT52 I. LBITS PER CHAR {a =7BITS
, = ANSI I . 1=8BITS
iLKEYCLICK [0 =OFF L PARITY {a = OFF
L' =ON t..., = ON
L- MARGIN BELL {a, =_ OON
FF
PARITY SENSE {a =ODD
t...1 = EVEN
MA-1988
R SPEEDc::=J
Figure 1-6
SET-UP BMode Summary

10 OPERATOR INFORMATION
Determining What a SET-UP Feature Does
The SET-UP features are basically aseries of options in the VT100 that allow the
terminal to be tailored
to its operating environment. Table 1-1 lists each feature
and places
it in one or more of the following general categories:
InstaIlation
Computer compatibility
Operator
comfort
The installation category concerns itself with the initial installation of the terminal
and any special options
that may be attached to the terminal. If any terminal
options are added or removed. or the physical location
of the installation is
changed. verify the settings
of these SET -UPfeatures.
Computer compatibility contains the features which must be set correctly so that
the VT100 can communicate with the host computer. An error in these settings
may cause incorrect data
to be sent to or received from the computer; or an error
may prevent the
VT100 from communicating with the computer. The settings for
these features must be obtained from the host computer programmer. operator. or
system manager since there are many combinations
of settings designed to work
with particular computers and special software. These feature settings would nor-
mally change only when you need
to communicate with adifferent computer or a
unique software package.
The operator
comfort category contains the SET-UP features designed exclusively
for the operator. These features
allow the operator to tailor the VT100 to fit indi-
vidual preference. These features do
not affect any operations that occur between
the terminal and the computer.
The next section. Definition
of Each SET-UP Feature. describes the specific func-
tion
of each feature.
Table 1-1
Categories of SET-UP
Features
SET- UP Feature Installation
Computer
Compatibility
Operator
Comfort
ANSI/VT52 Mode
ANSWERBACK Message
AUTO REPEAT
AUTO XON XOFF
BITS
PER CHARACTER
CHARACTERS
PER LINE
CURSOR
INTERLACE X
KEYCLICK
LINE/LOCAL
MARGIN BELL
NEW LINE
PARITY
PARITY SENSE
POWER X
RECEIVE SPEED
SCREEN BACKGROUND
SCREEN BRIGHTNESS
SCROLL
TABS
TRANSMIT SPEED
WRAPAROUND
II(shifted)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

How to Change a SET-UP Feature
Changing any or all
of the SET-UP features is asimple operation and is generally
performed by
following the same basic steps.
1. Enter SET-UP mode by pressing the SET-UP key
2. Select the appropriate SET-UP mode by pressing the 5key on the main
keyboard each
time you want to switch from SET-UP A to SET-UP B or
from SET-UP B to SET-UP A.
3. Position the cursor above the feature switch
or tab stop to be changed.
Topositionthecursor,theSPACEBAR, a, a, TAB and RETURN
keys may be used. Some features do not use this step since aspecific
key
is dedicated to changing the feature.
4. Change the feature setting by pressing either the 6key on the main
keyboard or the appropriate dedicated key.
Each time the key is pressed
the feature
will change, generally to the opposite state.
Table
1-2 briefly summarizes the SET-UP features, the SET-UP mode you must be
in to change agiven feature, and the key used to change the feature setting.
OPERATOR INFORMATION
11
Table 1-2
SET-UP Feature
Change Summary
Changed In
Changed In
SET-UP SET·UP Key Used to
SET-UP SET-UP Key Used
to
SET-UP Feature
A Mode
BMode
Change Feature
SET-UP Feature A
Mode B Mode
Change Feature
ANSIIVT52 mode X•PARITY X•
ANSWERBACK message XtPARITY SENSE X•
AUTO REPEAT X•POWER X•
AUTO XON/XOFF X•
RECEIVE SPEED X•
BITS PER CHARACTER X•
SCREEN BACKGROUND X•
CHARACTERS PER LINE X•
SCREEN BRIGHTNESS XX
BorB
CURSOR X•SCROLL X•
INTERLACE X•TABS X
Band II
KEYCLICK X•TRANSMIT SPEED X
II
LINE/LOCAL X X •WRAPAROUND X•
MARGIN BELL X•II(shifted) X•
NEW LINE X•
fA special sequence is required for this feature.

12 OPERATOR INFORMATION
NOTE
The save operation must be
performed at the terminal
keyboard. The
computer can-
not perform this operation, al-
though it can temporarily
modify the settings of some
VT100 features.
NOTE
When arecall operation is
performed the contents of the
screen are destroyed.
Setting the Answerback Message
Setting the answerback message is different from setting any of the other terminal
features.
An answerback message can be typed into the VT100. using the follow-
ing steps:
1. Place the terminal in SET-UP Bmode.
2. Press
the SHIFT and Akey simultaneously. The terminal will respond
by placing A=on the screen. (The SHIFT key is required. The
CAPS LOCK key will not work here.)
3. Type the message delimiter character which may be any character
not
used in the actual answerback message. The message delimiter charac-
ter is
not apart of the answerback message. If amistake is made when
typing the answerback message. type the message delimiter character
again and
go back to step 2. This is the only way to correct errors in the
answerback message.
4. Type the answerback message. The message may
be up to 20 charac-
ters. including space and control characters. Control characters
will be
displayed as a • character to indicate their presence in the message.
5. Type the message delimiter character. Once the message delimiter
character is typed the answerback message
will disappear from the
screen.
Once the above steps have been completed the answerback message
will be tem-
porarily stored in the
VT100 and can be saved with the Save operation.
Saving
the SET- UP Features
SET-UP features may be changed and stored on either atemporary
or afixed
basis. To temporarily store afeature.
exit SET-UP mode after changing the feature;
the terminal
now reacts according to the new setting. If arecall operation is per-
formed. or the terminal is reset. or the terminal power is turned off. all temporary
feature settings are replaced by the features
that have been stored on afixed basis.
To store SET-UP feature settings on afixed basis. perform asave operation. This is
asimple operation
that is accomplished by performing the following steps:
1. Place the terminal in SET-UP mode.
2. Press the
SH IFT and Skeys simultaneously. The screen will clear and
the message
"wait'· will be displayed in the upper-left corner. After a
brief
wait. the terminal will return to SET-UP Amode.
Once these steps have been performed. SET-UP features which had been tempo-
rarily stored
will now be stored on afixed basis.
Recalling SET-U PFeatures
The temporarily stored
SET -UPfeature settings may differ from the settings which
have been stored on afixed basis.
If you wish to return to the fixed settings.
perform the recall operation
as follows:
1. Place the terminal in SET-UP mode.
2. Press the
SHIFT and Rkeys simultaneously. The screen will clear and
the message
"wait" will appear in the upper-left corner of the screen.
After abrief wait the terminal will return to SET-UP Amode.

Resetting the Terminal
The
VT100 may be reset from the keyboard. When the terminal is reset, the termi-
nal memory is cleared and the self-test program is run
as if the terminal power
switch had been turned
OFF and then back ON. To reset the terminal:
OPERATOR INFORMATION 13
1.
2.
Place the terminal in SET-UP mode.
Press the 0key on the main keyboard. The
VT100 will be reset the
power on self-test
will be run, and the terminal will set according to the
fixed
SET -UPfeatures.
NOTE
When areset operation is per-
formed the contents of the
screen are destroyed
and any
options present iTiay be af-
fected.
PART 3
DEFINITION
OF EACH
SET-UP FEATURE
This section describes each SET-UP feature
in detail (in alphabetical order) and
states
how each feature affects the terminal.
ANSI/VT52 Mode
The VT100 terminal follows two different programming standards -American
National Standards Institute (ANSI) and VT52. In ANSI mode, the
VT100 will
generate and respond
to coded sequences per ANSI standards X3.41-1974 and
X3.64-1977. In VT52 mode, the VT100 terminal is compatible with previous
DIGITAL software using the VT52 video terminal. Both ANSI and VT52 modes
are
outlined in the programmer's section of this manual.
ANSWERBACK Message
Answerback
is aquestion and answer sequence where the host computer asks the
terminal
to identify itself. The VT100 answerback feature provides the terminal
with the capability to identify itself by sending amessage to the host. The entire
answerback sequence takes place automatically
without affecting the screen or
requiring operator action. The answerback message may also
be transmitted by
typing
CTRL- BREAK.
AUTO REPEAT
The auto repeat feature allows akey to
be automatically repeated at the rate of
about 30 characters per second when the key is held down for more than one-half
second. The auto repeat feature affects all keyboard keys except the following:
NOTE
Unless otherwise stated, en-
tering SET-UP mode and
changing features does not
result in the loss of data dis-
played on the screen.
SET-UP
ESC
NO SCROLL
TAB
RETURN
CTRLand any key
AUTO XON/XOFF
The VT100 is capable of automatically generating synchronizing codes XON (DC1)
and XOFF (DC3).
The XOFF code is used to stop the transmission of data from the
computer
to the terminal; the XON code is used to resume transmission. With the
feature enabled. the
VT100 will generate the XOFF code when one of the follow-
ing events occur:
1. The internal buffer is nearly full
2. The
NO SCROLL key is pressed
3. The terminal is placed in SET-UP mode
4.
CTRL- S is pressed.
NOTE
The
VT100 will always stop
transmission when an XOFF
(DC3) code is received
and
will resume transmission
when an XON (DC1) code is
received regardless
of the
AUTO XON/XOFF feature set-
ting.