The numbering of the lines depends upon the state of the Origin Mode (DECOM).
This control sequence is sent in reply to a device status report (DSR) command sent from the host. defn CUB Cursor Backward attr VT100 ANSI Command Event code ESC [ {Pn} D dflt 1 html The CUB sequence move the cursor to the left. The distance moved is determined by the parameter. If the parameter missing, zero, or one, the cursor is moved one position. The cursor cannot be moved past the left margin. defn CUD Cursor Down attr VT100 ANSI Command Event code ESC [ {Pn} B dflt 1 html Moves the cursor down a number of lines as specified in the parameter without changing columns. The cursor cannot be moved past the bottom margin. defn CUF Cursor Foreward attr VT100 ANSI Command Event code ESC [ {Pn} C dflt 1 html The CUF sequence moves the cursor to the right a number of positions specified in the parameter. The cursor cannot be moved past the right margin. defn CUP Cursor Position attr VT100 ANSI Command code ESC [ {Pn} ; {Pn} H dflt 1 1 html The CUP sequence moves the curor to the position specified by the parameters. The first parameter specifies the line, and the second specifies the column. A value of zero for either line or column moves the cursor to the first line or column in the display. The default string (<ESC>H) homes the cursor. In the VT100, this command behaves identically to it's format effector counterpart, HVP.
The numbering of the lines depends upon the state of the Origin Mode (DECOM). defn CUU Cursor Up attr VT100 ANSI Command Event code ESC [ {Pn} A dflt 1 html Moves the cursor up without changing columns. The cursor is moved up a number of lines as indicated by the parameter. The cursor cannot be moved beyond the top margin. defn DA Device Attributes attr VT100 ANSI Command Reply code ESC [ {Pn} c dflt 0 html The host requests the VT100 to send a DA sequence to indentify itself. This is done by sending the DA sequence with no parameters, or with a parameter of zero.
Response to the request described above (VT100 to host) is generated by the VT100 as a DA control sequence with the numeric parameters as follows:
| Option Present | Sequence Sent |
| No options | <ESC>[?1;0c |
| Processor Option (STP) | <ESC>[?1;1c |
| Advanced Video Option (AVO) | <ESC>[?1;2c |
| AVO and STP | <ESC>[?1;3c |
| Graphics Option (GPO) | <ESC>[?1;4c |
| GPO and STP | <ESC>[?1;5c |
| GPO and AVO | <ESC>[?1;6c |
| GPO, ACO, and STP | <ESC>[?1;7c |
ESC # 3 Top Half
ESC # 4 Bottom Half
These sequences cause the line containing the cursor to become the top or bottom half of a double-height, double width line. The sequences should be used in pairs on adjacent lines with each line containing the same character string. If the line was single width single height, all characters to the right of the center of the screen will be lost. The cursor remains over the same character position, unless it would be to the right of the right margin, in which case it is moved to the right margin. defn DECDWL Double Width Line attr VT100 DEC Command code ESC # 6 html This causes the line that contains the cursor to become double-width single height. If the line was single width, all characters ro the right of the center of the screen will be lost. The cursor remains over the same character position, unless it would be to the right of the right margin, in which case it is moved to the right margin. defn DECID Identify Terminal attr VT100 DEC Command code ESC Z html This sequence causes the same response as the DA sequence. This sequence will not be supported in future models. defn DECINLM Interlace Mode attr VT100 DEC Mode html This is a private parameter to the RM and SM control sequences. The reset state (non-interlace) causes the video processor to display 240 scan lines per frame. The set state causes the video processor to display 480 scan lines per screen. See MODES, RM, and SM. defn DECKPAM Keypad Application Mode attr VT100 DEC Command Mode code ESC = html The auxiliary keypad keys will transmit control sequences. defn DECKPNM Keypad Numeric Mode attr VT100 DEC Mode Command code ESC > html The auxiliary keypad keys will send ASCII codes corresponding to the characters engraved on their keys. defn DECLL Load LEDs attr VT100 DEC Command code ESC [ {Ps} q dflt 0 html Load the four programmable LEDs on the keyboard according to the parameter(s).
| Parameter | Meaning |
| 0 | Clear All LEDs |
| 1 | Light L1 |
| 2 | Light L2 |
| 3 | Light L3 |
| 4 | Light L4 |
The set state causes the origin to be at the upper left character position within the current margins. Line and column numbers are, therefore, relative to the current margin settings. The cursor cannot be positioned outside of the margins.
The cursor is moved to the new home position when this mode is set or reset. Lines and columns are numbered consecutively, with the origin being line 1, column 1. defn DECRC Restore Cursor attr VT100 DEC Command code ESC 8 html This sequence causes the previously saved cursor position, graphic rendition, and character set to be restored. defn DECREPTPARM Report Terminal Parameters attr VT100 ANSI Reply code ESC [ {sol} ; {par} ; {nbits} ; {xspd} ; {rspd} ; {cmul} ; {flags} x html This sequence is generated by the VT100 to notify the host of the status of selected terminal parameters. The status sequence may be sent when requested by the host (via DECREQTPARM) or at the terminal's discretion. On power up or reset, the VT100 is inhibited from sending unsolicited reports.
The meanings of the sequence paramters are:
| Parameter | Value | Meaning |
| {sol} | 1 | This message is a report. |
| 2 | This message is a report, and the terminal is only reporting on request. | |
| {par} | 1 | No parity set |
| 4 | Parity set and odd | |
| 5 | Parity set and even | |
| {nbits} | 1 | 8 bits per character |
| 2 | 7 bits per character | |
| {xspd} and {rspd}
{xspd} = Transmit Speed {rspd} = Recieve Speed |
0 | Speed set to 50 bps |
| 8 | Speed set to 75 bps | |
| 16 | Speed set to 110 bps | |
| 24 | Speed set to 134.5 bps | |
| 32 | Speed set to 150 bps | |
| 40 | Speed set to 200 bps | |
| 48 | Speed set to 300 bps | |
| 56 | Speed set to 600 bps | |
| 64 | Speed set to 1200 bps | |
| 72 | Speed set to 1800 bps | |
| 80 | Speed set to 2000 bps | |
| 88 | Speed set to 2400 bps | |
| 96 | Speed set to 3600 bps | |
| 104 | Speed set to 4800 bps | |
| 112 | Speed set to 9600 bps | |
| 120 | Speed set tp 19200 bps | |
| {cmul} | 1 | The bit rate multiplier is 16 |
| {flags} | 0-15 | This value communicates the four switch values in block 5 of SET-UP B, which are only visible to the user when an STP option is installed. |
Default is the entire screen (no margins). The minimum region allowed is two lines, i.e., the top line must be less than the bottom. The cursor is placed in the home position (See DECOM). defn DECSWL Single-width Line attr VT100 DEC Command code ESC # 5 html This causes the line which contains the cursor to become single-width, single-height. The cursor remains on the same character position. This is the default condition for all new lines on the screen. defn DECTST Invoke Confidence Test attr VT100 ANSI Command code ESC [ 2 ; {Ps} y html Ps is the parameter indicating the test to be done. It is computed by taking the weight indicated for each desired test and adding them together. If Ps is 0, no test is performed but the VT100 is reset.
| Test | Weight |
| POST (ROM checksum, RAM NVR, keyboardm and AVO) | 1 |
| Data Loop Back (Loopback connector required) | 2 |
| EIA Modem Control Test (Loopback connector req.) | 4 |
| Repeat Testing until failure | 8 |
| Parameter | Direction | Meaning |
| 0 | to host | Ready, no faults detected |
| 3 | to host | Malfunction Detected |
| 5 | to VT100 | Report Status (using a DSR control sequence) |
| 6 | to VT100 | Report Active Position (using a CPR sequence) |
DSR with a parameter of 0 or 3 is always sent as a response to a requesting DSR with a parameter of 5. defn ED Erase in Display attr VT100 ANSI Command code ESC [ {Ps} J dflt 0 html This sequence erases some or all of the characters in the display according to the parameter. Any complete line erased by this sequence will return that line to single width mode.
| Parameter | Meaning |
| 0 | Erase from the cursor to the end of the screen. |
| 1 | Erase from the start of the screen to the cursor. |
| 2 | Erase the entire screen. |
| Parameter | Meaning |
| 0 | Erase from cursor to the end of the line. |
| 1 | Erase from the start of the line to the cursor. |
| 2 | Erase the entire line. |
The set state causes the <LF> character to imply movement to the first position of the following line, and causes the RETURN key to send the code pair <CR><LF>. This is the New Line option.
This mode does not affect the Index (IND) or the next line
(NEL) format effectors.
defn NEL Next Line
attr VT100 ANSI Command
code ESC E
html
This causes the cursor to move to the first position of the next line
down. If the cursor is on the bottom line, a scroll is performed.
defn RI Reverse Index
attr VT100 ANSI Command
code ESC M
html
Move the cursor up one line without changing columns. If the cursor is
on the top line, a scroll down is performed.
defn RIS Reset to Initial State
attr VT100 ANSI Command
code ESC c
html
Resets the VT100 to the state is has upon power up. This also causes
the execution of the POST and signal INT H to be asserted briefly.
defn RM Reset Mode
attr VT100 ANSI Command
code ESC [ {Ps} ; ... l
html
Resets one or more VT100 modes as specified by each selective parameter
in the parameter string. Each mode to be reset is specified by a
separate parameter. See MODES and SM.
defn SCS Select Character Set
attr VT100 ANSI Command
html
<ESC;>( {Cs} Select G0 Set
<ESC;>) {Cs} Select G1 Set
The appropriate D0 and G1 character sets are designated from one of the five possible sets. The G0 and G1 sets are invokedd by the characters <SI> and <SO>, respectively.
| Parameter | Meaning |
| A | United Kingdom Set |
| B | ASCII Set |
| 0 | Special Graphics |
| 1 | Alternate Character ROM Standard Character Set |
| 2 | Alternate Character ROM Special Graphics |
The United Kingdom and ASCII sets conform to the "ISO international register of character sets to be used with escape sequences". The other sets are private character sets. Special graphics means that the graphic characters fpr the codes 0137 to 0176 are replaced with other characters. The specified character set will be used until another SCS is recieved. defn SGR Select Graphic Rendition attr VT100 ANSI Command code ESC [ {Ps} ; ... m html Invoke the graphic rendition specified by the parameter(s). All following characters transmitted to the VT100 are rendered according to the parameter(s) until the next occurrence of an SGR.
| Parameter | Meaning |
| 0 | Attributes Off |
| 1 | Bold or increased intensity |
| 4 | Underscore |
| 5 | Blink |
| 7 | Negative (reverse) image |
All other parameter values are ignored.
Without the Advanced Video Option, only one type of character attribute is possible, as determined by the cursor selection; in that case specifying either underscore or reverse will activate the currently selected attribute. defn SM Set Mode attr VT100 ANSI Command code ESC [ {Ps} ; ... h html Causes one or more modes to be set within the VT100 as specified by each selective parameter string. Each mode to be set is specified by a seperate parameter. A mode is considered set until it is reset by a Reset Mode (RM) control sequence. See RM and MODES.
[Editor's note: The original DEC VT100 documentation EK-VT100-UG-003 erroneously omitted the "[" character from the SM sequence.] defn TBC Tabulation Clear attr VT100 ANSI Command code ESC [ {Ps} g html If the parameter is missing or 0, this will clear the tab stop at the cursor's position. If it is 3, this will clear all of the tab stops. Any other parameter is ignored.