Secondary DA reply decoder — `CSI > Pp ; Pv ; Pc c` model / firmware / cart

Byte forms

Every common string-literal form so you can paste-and-search either direction.

Description

The *reply* shape for secondary DA (request side documented under csi-da). The application sends \x1b[>c (or \x1b[>0c); the terminal answers \x1b[>Pp;Pv;Pc c on stdin. TUIs branch on Pp to pick a feature set and on Pv to enable per-version workarounds — this page is the lookup table.

Pp — model code:

- 0 — DEC VT100 (or terminal claiming VT100 compatibility — common from minimal embedded emulators). - 1 — DEC VT220. - 2 — DEC VT240 / VT241. - 18 — DEC VT330. - 19 — DEC VT340. - 24 — DEC VT320. - 28 — DEC VT330 (alternative). - 32 — Tek 4014. - 41 — DEC VT420. - 61 — DEC VT510 (and most xterm-class emulators, including xterm itself patch ≥ 95). - 64 — DEC VT520. - 65 — DEC VT525 (and Kitty, Alacritty, WezTerm, iTerm2 all use 65 as a 'modern xterm-class' marker by convention; Ghostty uses 65 too). - 82 — rxvt. - 83 — Eterm. - 84 — sun terminal. - 85 — rxvt-unicode (urxvt).

Pv — firmware / version:

- DEC hardware: literal ROM version (e.g. xterm patch level → Pv = 95+). - xterm: Pv is the xterm patch level — \x1b[>61;392;0c means xterm patch 392. - Kitty: Pv encodes the version — Pv = major*10000 + minor*100 + patch, so 0.41.1 → 4101 (older versions used base-100, check current behaviour). - WezTerm: Pv is a build year-month — e.g. 4604 ≈ 2024.10 build. - Alacritty: Pv is fixed at 0 (Alacritty doesn't expose version this way; use XTVERSION instead — see xtversion). - iTerm2: Pv is fixed at 95 (frozen at the original xterm-95 marker for compatibility — use XTVERSION for the real version). - Ghostty: Pv is the build patch level. - Windows Terminal: Pv is the WT version major*100 + minor (e.g. 0 for 1.0, 18 for 1.18).

Pc — cartridge / serial: - DEC hardware: ROM cartridge number, almost always 0 on serial-only models. - Software emulators: always 0. - Treat any non-zero Pc as informational only — no portable meaning.

Recommended consumer pattern: ``` match (Pp, Pv) { (65, v) if v >= 1000 => 'modern xterm-class' # Kitty / WezTerm / Alacritty / iTerm2 (64, _) => 'VT520 or VT520-compat' (61, _) => 'xterm or xterm-class' (41, _) => 'VT420 or VT420-compat' (1, _) => 'VT220 or VT220-compat' (0, _) => 'VT100 or minimal' _ => 'unknown — feature-detect via XTVERSION or DECRQM' } ```

Don't trust DA2 for fine-grained feature detection — Pp coverage is coarse and Pv encoding is per-emulator. For 'does this terminal support feature X' use XTVERSION (xtversion) for the emulator name + version, then DECRQM (decrqm) to query the specific mode bit. Use DA2 only for the broad model bucket.

Spec citation: xterm-ctlseqs (Secondary DA reply) / DEC VT320+ DA2

Parameters

Examples

# Ask + decode model bucket.\nold=$(stty -g); stty -echo raw min 0 time 1\nprintf '\033[>c' > /dev/tty\nIFS= read -r -d c reply < /dev/tty\nstty "$old"\npp=$(echo "$reply" | sed -nE 's/.*>([0-9]+);.*/\\1/p')\ncase "$pp" in\n    0)   echo 'VT100 / minimal' ;;\n    1)   echo 'VT220-compat' ;;\n    41)  echo 'VT420-compat' ;;\n    61)  echo 'xterm-class' ;;\n    65)  echo 'modern xterm-class (Kitty/WezTerm/Alacritty/iTerm2/Ghostty)' ;;\n    82)  echo 'rxvt' ;;\n    85)  echo 'urxvt' ;;\n    *)   echo "unknown model: $pp" ;;\nesac

import sys, termios, tty, re\nMODELS = {0:'VT100/minimal',1:'VT220',41:'VT420',61:'xterm-class',64:'VT520',65:'modern xterm-class',82:'rxvt',85:'urxvt'}\nfd = sys.stdin.fileno(); old = termios.tcgetattr(fd); tty.setraw(fd)\ntry:\n    sys.stdout.write('\x1b[>c'); sys.stdout.flush()\n    buf = b''\n    while not buf.endswith(b'c'): buf += sys.stdin.buffer.read1(64)\n    m = re.search(rb'>(\d+);(\d+);(\d+)c', buf)\n    pp, pv, pc = (int(x) for x in m.groups())\n    print(f'model={MODELS.get(pp, "unknown")} ({pp}); version={pv}; cart={pc}')\nfinally:\n    termios.tcsetattr(fd, termios.TCSADRAIN, old)

// Decode the (Pp, Pv) bucket — Pc is informational.\nvar models = map[int]string{0:\"VT100\",1:\"VT220\",41:\"VT420\",61:\"xterm-class\",64:\"VT520\",65:\"modern xterm-class\",82:\"rxvt\",85:\"urxvt\"}\nfunc decodeDA2(reply string) (string, int) {\n    var pp, pv, pc int\n    fmt.Sscanf(reply, \"\\x1b[>%d;%d;%dc\", &pp, &pv, &pc)\n    return models[pp], pv\n}

// Parse a DA2 reply string into a labelled bucket.\nfunction decodeDA2(reply) {\n    const m = reply.match(/>(\d+);(\d+);(\d+)c/);\n    if (!m) return null;\n    const [pp, pv, pc] = m.slice(1).map(Number);\n    const models = {0:'VT100',1:'VT220',41:'VT420',61:'xterm-class',64:'VT520',65:'modern xterm-class',82:'rxvt',85:'urxvt'};\n    return { model: models[pp] || `unknown(${pp})`, version: pv, cartridge: pc };\n}

/* Decode a DA2 reply already buffered in `reply`. */\nint pp = 0, pv = 0, pc = 0;\nif (sscanf(reply, \"\\x1b[>%d;%d;%dc\", &pp, &pv, &pc) == 3) {\n    /* branch on pp / pv */\n}

Terminal support

xterm

yes

Linux console (fbcon)

partial

macOS Terminal.app

partial

iTerm2

yes

Windows Terminal

yes

cmd.exe / ConPTY

partial

kitty

yes

alacritty

partial

WezTerm

yes

Ghostty

yes

GNOME Terminal

yes

Konsole

yes

tmux

yes

GNU screen

yes

Related sequences

• DA — Device Attributes (CSI c / CSI > c)
• XTVERSION — Report terminal name and version (CSI > Pp q)
• DECRQM — Request Mode Status (CSI ? Ps $ p)
• CSI ? Ps n — Private DSR (extended status queries)

In the family cookbook

↗CSI cookbook · 4. Queries — DA, DA2, DSR, DECRQM