# VT100 (enhanced) Programmer Information (Draft)
# Background
The VT132 faithfully implements almost all of the features of the original Digital Equipment Corporation (DEC) VT100, with the Advanced Video Option installed.
To this a range of enhancements have been added
- many are features of later DEC VT family terminals that have been implemented for convenience
- some are features of "standard" ANSI terminals (mainly IBM PC/MS DOS based terminal emulators)
- enhancements are highlighted by the addition of (enhancement) to the heading or description
A good reference for an owner of a VT100 (especially getting started with the Setup screens) is the original VT100 Users Guide over at VT100.net. Details of what the Advanced Video Option adds can be found here also.
The remainder of this section will largely focus on where the VT132 implementation of the VT100 differs to an original VT100.
TIP
Each heading is a link to the corresponding section of Chapter 3 of the original VT100 Users Guide
# The Keyboard
# LED Indicators
The original VT100 keyboard had 7 LED indicators, the VT132 does not.
On the VT132:
- The ON-LINE/LOCAL status is indicated on each Setup screen in the top right-hand corner as either
ONLINEorLOCALand also in the Quick Menu, on the root menu, by the checkbox item[X]On-linefor ON-LINE and[ ]On-linefor LOCAL. - There is no support for the "keyboard locked" condition.
- The four remaining, programmable LEDs are represented as follows:
- L1, L2 and L3 are mapped to the 3 PC keyboard LEDs for
<Num Lock>,<Caps Lock>and<Scroll Lock>(if present)- Sending an escape sequence to turn on/off any of L1, L2 or L3 will change the corresponding LED on the keyboard
- Pressing one of the 3 key-lock keys
<Num Lock>,<Caps Lock>and<Scroll Lock>will override the value displayed for L1, L2 or L3
- L4 is not mapped to anything is so is not visible
- L1, L2 and L3 are mapped to the 3 PC keyboard LEDs for
# SET-UP
The SET-UP key is mapped to <Alt><SysReq> or <Alt><PrintScreen>
# NO SCROLL
The NO SCROLL key is mapped to the <Scroll Lock> key on a PC keyboard and is equivalent to pressing <Ctrl><S> and <Ctrl><Q> alternatively.
# BREAK
The BREAK key function is not implemented by the VT132.
# Communications Protocols
# Full Duplex
The VT132 supports baud rates from 300 to 115200 and the Transmit and Receive speed must be the same. The available speeds are 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 corresponding to the speeds supported by most serial interface cards based on the available clock settings.
# Terminal Control Commands
# Control Characters
The following table details the control characters the VT132 responds to.
There are two columns indicating whether the control character action is implemented, one for VT100 mode and one for ANSI.SYS compliance mode as the set of control characters differs depending on the current mode.
| Control Character | Octal Code | Hex Code | Action Taken | VT100 | ANSI.SYS |
|---|---|---|---|---|---|
| NUL | 000 | 0x00 | Ignored on input | No | No |
| ENQ | 005 | 0x05 | Transmit answer-back message | Yes | No |
| BEL | 007 | 0x07 | Sound bell tone from buzzer | Yes | Yes |
| BS | 010 | 0x08 | Move the cursor to the left one character position, unless it is at the left margin, in which case no action occurs | Yes | Yes |
| HT | 011 | 0x09 | Move the cursor to the next tab stop, or to the right margin if no further tab stops are present on the line | Yes | Yes |
| LF | 012 | 0x0A | This code causes a line feed or a new line operation. (See new line mode). | Yes | Yes |
| VT | 013 | 0x0B | Interpreted as LF - TBA | Yes | Yes |
| FF | 014 | 0x0C | Interpreted same as VT | Yes | Yes |
| CR | 015 | 0x0D | Move cursor to the left margin on the current line | Yes | Yes |
| SO | 016 | 0x0E | Invoke G1 character set, as designated by SCS control sequence. | Yes | No |
| SI | 017 | 0x0F | Select G0 character set, as selected by ESC ( sequence | Yes | No |
| XON | 021 | 0x11 | Causes terminal to resume transmission | Yes | Yes |
| XOFF | 023 | 0x13 | Causes terminal to stop transmitted all codes except XOFF and XON | Yes | Yes |
| SUB | 030 | 0x18 | Not implemented | No | No |
| CAN | 032 | 0x1A | Not implemented | No | No |
| ESC | 033 | 0x1B | Invokes a control sequence | Yes | Yes |
| DEL | 177 | 0x7F | Ignored on input | Yes | Yes |
TIP
Control Characters in the ranges named C0 (0x00-0x1F) and C1 (0x80-0x9F) are normally considered non-printable characters. This is true for the VT100 (and all terminal personalities included in the VT132).
The exception is when ANSI.SYS compliance is enabled.
In this mode only the Control Characters listed above with Yes in the ANSI.SYS column are considered non-printable. All other Control Characters will be output to the terminal, showing the corresponding glyph from the currently selected font. This is designed to allow a greater range of the CP437 character set to be output to the terminal and many of these glyphs are used in BBSs to display extra symbols and also in ANSI art.
# Control Sequences
The following tables of Control Sequences are grouped into 4 categories:
- Original VT100 Control Sequences
- Additional Control Sequences from later models of VT family terminals
- ANSI.SYS Control Sequences specific to ANSI.SYS support
- Original VT52 Control Sequences
# Original VT100 Control Sequences
| Control Sequence | Name | Action Taken | Default Value |
|---|---|---|---|
ESC [ Pn ; Pn R | CPR | Cursor Position Report Response to DSR | |
ESC [ Pn D | CUB | Cursor Backward | 1 |
ESC [ Pn B | CUD | Cursor Down | 1 |
ESC [ Pn C | CUF | Cursor Forward | 1 |
ESC [ Pn ; Pn H | CUP | Cursor Position | 1 |
ESC [ Pn A | CUU | Cursor Up | 1 |
ESC [ Pn c | DA | Device Attributes | 0 |
ESC [ ? 1 ; Pn c | DA | Device Attributes response Hardcoded to: Esc [ ? 64 ; 1 ; 6 ; 22 c | |
ESC # 8 | DECALN | Screen Alignment Display | |
ESC [ ? 2 l | DECANM | ANSI/VT52 Mode | |
ESC [ ? 8 h/l | DECARM | Auto Repeat Mode | |
ESC [ ? 7 h/l | DECAWM | Auto-wrap Mode | |
ESC [ ? 1 h/l | DECCKM | Cursor Keys Mode | |
ESC [ ? 3 h/l | DECCOLM | 132/80 Column Mode | |
ESC # 3 | DECDHL | Double Height Line -Top Half | |
ESC # 4 | DECDHL | Double Height Line - Bottom Half | |
ESC # 6 | DECDWL | Double Width Line | |
ESC Z | DECID | Identify Terminal | |
ESC [ ? 9 h/l | DECINLM | Interlace Mode 480/240 scan lines | |
ESC = | DECKPAM | Keypad Application Mode | |
ESC > | DECKPNM | Keypad Numeric Mode | |
ESC [ Ps q | DECLL | Load LEDS | 0 |
ESC [ ? 6 h/l | DECOM | Origin Mode | |
ESC 8 | DECRC | Restore Cursor Paired with DECSC | |
ESC [ <sol>; ... x | DECREPTPARM | Report Terminal Parameters NOT IMPLEMENTED | |
ESC [ <sol> x | DECREQTPARM | Request Terminal Parameters NOT IMPLEMENTED | |
ESC 7 | DECSC | Save Cursor Paired with DECRC | |
ESC [ ? 4 h/l | DECSCLM | Scrolling Mode Smooth/Jump scrolling | |
ESC [ ? 5 h/l | DECSCNM | Screen Mode Reverse/Normal | |
ESC [ Pn; Pn r | DECSTBM | Set Top and Bottom Margins Minimum 2 lines | whole screen |
ESC # 5 | DECSWL | Single-width Line | |
ESC [ 2 ; Ps y | DECTST | Invoke Confidence Test NOT IMPLEMENTED | |
ESC [ Ps n | DSR | Device Status Report | 0 |
ESC [ Ps J | ED | Erase In Display | 0 |
ESC [ Ps K | EL | Erase In Line | 0 |
ESC H | HTS | Horizontal Tabulation Set | |
ESC [ Pn ; Pn f | HVP | Horizontal and Vertical Position | 1 |
ESC D | IND | Index | |
ESC [ 20 h/l | LNM | Line Feed/New Line Mode | |
ESC E | NEL | Next Line | |
ESC M | RI | Reverse Index | |
ESC c | RIS | Reset To Initial State | |
ESC [ Ps ; ... l | RM | Reset Mode | none |
| SCS | Select Character Set | ||
ESC ( A | SCS - G0 | G0 - United Kingdom Set | |
ESC ( B | SCS - G0 | G0 - ASCII Set | |
ESC ( 0 | SCS - G0 | G0 - Special Graphics | |
ESC ( 1 | SCS - G0 | G0 - Alt Standard Character Set | |
ESC ( 2 | SCS - G0 | G0 - Alt Special Graphics | |
ESC ) A | SCS - G1 | G1 - United Kingdom Set | |
ESC ) B | SCS - G1 | G1 - ASCII Set | |
ESC ) 0 | SCS - G1 | G1 - Special Graphics | |
ESC ) 1 | SCS - G1 | G1 - Alt Standard Character Set | |
ESC ) 2 | SCS - G1 | G1 - Alt Special Graphics | |
ESC [ Ps ; ... m | SGR | Select Graphics Rendition | |
ESC [ 0 m | SGR | Attributes Off | |
ESC [ 1 m | SGR | Bold or Increased Intensity | |
ESC [ 4 m | SGR | Underscore | |
ESC [ 5 m | SGR | Blink | |
ESC [ 7 m | SGR | Negative (reverse/inverse) image | |
ESC [ Ps ; ... h | SM | Set Mode | |
ESC [ Ps g | TBC | Tabulation Clear | 0 |
# Additional Control Sequences
| Control Sequence | Mnemonic | Action Taken | Notes |
|---|
TBA
# ANSI.SYS Control Sequences
| Control Sequence | Mnemonic | Action Taken | Notes |
|---|---|---|---|
ESC [ s | SCOSC | Save current cursor state (position and attributes) | Does the same as ESC 7 |
ESC [ u | SCORC | Restore current cursor state (position and attributes) | Does the same as ESC 8 |
# XTERM Control Sequences
| Control Sequence | Mnemonic | Action Taken | Notes |
|---|---|---|---|
ESC [ Ps b | REP | Repeat the preceding graphic character Ps times | otherwise ignored |
# Original VT52 Control Sequences
| Control Sequence | Action Taken |
|---|---|
ESC A | Cursor Up |
ESC B | Cursor Down |
ESC C | Cursor Right |
ESC D | Cursor Left |
ESC F | Enter Graphics Mode |
ESC G | Exit Graphics Mode |
ESC H | Cursor to Home |
ESC I | Reverse Line Feed |
ESC J | Erase to End of Screen |
ESC K | Erase to End of Line |
ESC Y line column | Direct Cursor Address |
ESC Z | Identify |
ESC / Z | Identify response |
ESC = | Enter Alternate Keypad Mode |
ESC > | Exit Alternate Keypad Mode |
ESC < | Enter ANSI Mode |