DA1

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Standard

DA1 (Primary Device Attributes) is a CSI sequence that queries the terminal for its identity and supported features. The terminal responds with a list of attribute codes.

Syntax

CSI c         DA1 request (query)
CSI ? Pp ; ... c   DA1 response

Formal syntax

(* Request *)
DA1-request  = 0x1b, "[", [ "0" ], "c" ;

(* Response *)
DA1-response = 0x1b, "[", "?", Pp, { ";", Ps }, "c" ;
Pp = digit, { digit } ;                 (* terminal type *)
Ps = digit, { digit } ;                 (* feature code *)
digit = "0" | "1" | "2" | "3" | "4"
    | "5" | "6" | "7" | "8" | "9" ;

Description

Per the VT510 manual, the host sends CSI c (or CSI 0 c) to request the terminal's primary device attributes. The terminal responds with CSI ? Pp ; Ps ; ... c where Pp identifies the terminal type and the Ps values indicate supported features.

Common response types

The leading Pp value identifies the terminal class:

Value	Terminal type
`1`	VT100
`6`	VT102
`62`	VT220
`63`	VT320
`64`	VT420
`65`	VT510/VT520

Feature codes

Common Ps feature attribute values include:

Code	Feature
`1`	132 columns
`4`	Sixel graphics
`6`	Selective erase
`9`	National Replacement Character sets
`15`	Technical character set
`22`	ANSI color (VT525)

Most modern terminal emulators respond as a VT220 (?62) or higher with various feature flags. The exact response varies by terminal and is a common method for feature detection.

Examples

# Send DA1 query and read response
printf '\e[c'
# Typical XTerm response: ESC[?62;4;6;22c

Specifications

Specification	Section
VT510 Reference	—

Terminal support

Terminal	Support	Version	Notes
Terminal Emulators
Alacritty	✓	Yes	Reports VT102 (ESC [?6c)
Bobcat	✓	0.9.0	Supported via TerminalCtrl library; device ID set as 'Bobcat <version>' (Terminal.cpp:35)
contour	✓	v0.1.0
foot	✓	Yes	Implemented at csi.c:822-875, reports as VT220 with sixel and color support
Ghostty	✓	v1.0.0
iTerm2	✓	Yes	Primary device attributes (DA1) fully implemented with VT100CSI_DA token type. Reports various capabilities based on terminal type and emulation level.
Kitty	✓	Yes	Responds with callback to on_da1
Konsole	✓	Yes	Reports VT220 with capabilities via CSI ? 62 ; 1 ; 4 c
mintty	✓	Yes	Implemented in write_primary_da() at src/termout.c:880. Reports different DA strings based on terminal type configuration (vt100-vt500).
mlterm	✓	Yes	Supported since early versions, customizable via primary_da config
PuTTY	✓	0.43	Primary DA (CSI c) returns VT102 response at terminal.c:4509-4515
Rio	✓	v0.0.3	Reports VT220 with ANSI color, VT320 rectangles, and user windows
rxvt-unicode	✓	1.2	Reports VT100_ANS: ESC[?1;2c
st	✓	0.3	Responds with VT102 identity (vtiden configurable)
terminology	✓	v0.4.0	Reports VT510 with sixel, selective erase, color support
VT100	✓	Yes
VTE	✓	Yes	Supports VT520 level with 132-column mode, sixel graphics (conditional), horizontal scrolling, color text, and rectangular editing
WezTerm	✓	Yes	RequestPrimaryDeviceAttributes returns VT500 with capabilities
Windows Terminal	✓	Yes	Reports conformance level 61 with extensions 4,6,7,14,21,22,23,24,28,32,42,52
xterm	✓	Yes	VT100 feature, supported since earliest versions
xterm.js	✓	2.3.0
Multiplexers
cy	✓	v0.1.0	Responds with CSI ?6c
GNU Screen	✓	v.4.2.0	CSI c reports VT100 with parameters 1;2 at src/ansi.c:1041-1043
tmux	✓	1.3	Responds with VT220 attributes; Sixel support (4) included if compiled with ENABLE_SIXEL
tuios	✓	v0.0.15	Reports VT220 with 132 columns, selective erase, national replacement charset, technical characters, windowing capability, and ANSI color
Zellij	✓	v0.12.0	Reports VT220 with Sixel support (ESC[?62;4c)

Syntax​

Description​

Common response types​

Feature codes​

Examples​

Specifications​

Terminal support​

See also​