DECPS — Play Sound (`CSI Pv ; Pd ; Pn1 [; …] , ~`)

Byte forms

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

Description

DECPS — *Play Sound* — was added in the DEC VT520 to play one or more tones through the terminal's beeper. Xterm and several modern emulators (WezTerm, Ghostty, mlterm) implement it; for everyone else it's a silent no-op (which is usually the desired fallback — accessibility-conscious users disable terminal sound anyway).

Parameters: - Pv — volume (0 = off, 1–3 = low, 4–7 = high). Most emulators map to a binary 'play / silent' since their underlying audio API has no volume control here. - Pd — duration in 1/32-of-a-second units; 8 = 0.25s. Range 0–255. - Pn1; Pn2; … — one or more MIDI-ish note numbers from 0 (silence) through 25 (C7 in the DEC table). 0 = rest, 1 = C5, 2 = C#5, … 13 = C6, … 25 = C7. Multiple notes are played sequentially (not chord-style), each at the same Pv/Pd.

Common note codes (DEC VT520 RM Appendix A): - 1=C5 2=C#5 3=D5 4=D#5 5=E5 6=F5 7=F#5 8=G5 9=G#5 10=A5 11=A#5 12=B5 - 13=C6 14=C#6 … 25=C7

'Ode to Joy' opener as a sanity-check tune (E E F G G F E D C C D E E D D, all at Pv=5 Pd=4): \x1b[5;4;5;5;6;8;8;6;5;3;1;1;3;5;5;3;3,~.

Use cases: long-build completion chime (CI tool plays a 2-note 'done' upon make exit), distinctive failure tone (red SGR + DECPS 3-note descending pattern), accessibility-friendly notification when OSC 9 desktop-notification would be too noisy. Don't use for every keystroke — it's blocking on most emulators (the terminal's audio thread serialises with the parser).

Coverage: xterm = full (reference). WezTerm = full ≥ 20240127. Ghostty = full. mlterm = full. Konsole = partial (volume ignored, plays the system bell instead). iTerm2 = partial (plays a single beep regardless of Pn). Kitty = no-op by default; opt-in via enable_audio_bell. Alacritty / Linux console / macOS Terminal / Windows Terminal / cmd / ConPTY / gnome-terminal = silent no-op.

Accessibility note: respect NO_COLOR-style hints — many users have terminal sound permanently muted at the OS level. Don't lean on DECPS for *critical* signals; treat it as a polish nicety alongside a visible status indicator.

Spec citation: DEC VT520 RM Appendix A (DECPS) / xterm-ctlseqs (CSI Pv ; Pd ; Ps ; ... , ~)

Parameters

Examples

# Single quarter-second A5 'ding' at medium volume.\nprintf '\\033[5;8;10,~'

import sys\n# Build-complete two-note chime: C6 then E6, half second each.\nsys.stdout.write('\\x1b[5;16;13;17,~')\nsys.stdout.flush()

// Failure tone: descending three notes E5 -> C5 -> A4-equivalent rest.\nfmt.Print(\"\\x1b[6;6;5;3;1,~\")

// 'Ode to Joy' opening line.\nprocess.stdout.write('\\x1b[5;4;5;5;6;8;8;6;5;3;1;1;3;5;5;3;3,~');

/* Three quick high-pitched warning beeps. */\nprintf(\"\\x1b[7;2;25;25;25,~\");

Terminal support

xterm

yes

Linux console (fbcon)

no

macOS Terminal.app

no

iTerm2

partial

Windows Terminal

no

cmd.exe / ConPTY

no

kitty

partial

alacritty

no

WezTerm

yes

Ghostty

yes

GNOME Terminal

no

Konsole

partial

tmux

yes

GNU screen

yes

Related sequences

• C0 controls — BS, HT, LF, CR, BEL (single-byte codes)
• DECSWBV / DECSMBV — Set warning / margin bell volume (CSI Ps SP t / CSI Ps SP u)
• OSC 9 — Toast notification (iTerm2 / Windows Terminal)