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DECSCLM — smooth scroll mode
DECSCLM (Scrolling Mode) toggles between smooth and jump scrolling via
CSI ? 4 h (smooth) and CSI ? 4 l (jump). On the original VT100, smooth scrolling animated text line-by-line at a visible speed, while jump scrolling snapped instantly — a noticeable difference on 1978 CRT hardware.
On modern terminals this distinction is largely cosmetic. Most terminals either ignore DECSCLM entirely or treat it as a no-op since rendering is already instantaneous. Contour implements it for completeness. xterm supports it and actually does render line-by-line in smooth mode, creating a retro scrolling effect.How this is testedpartial
Send CSI ? 4 h to enable smooth scroll, verify mode is set via DECRPM query.
Send CSI ? 4 h to enable smooth scroll, verify mode is set via DECRPM query.
The same probe runs against headless backends (via Termless) and real terminal apps (via a daemon launched in each terminal). This lets us distinguish parser correctness from rendering correctness.
Supported by 0 of 14 backends (0%)
Terminal Applications
| Terminal | Version | Support | Notes |
|---|---|---|---|
| iTerm2 | 3.6.9 | ? unknown | |
| Ghostty | 1.3.1 | ? unknown | |
| VS Code | ? unknown | ||
| Kitty | 0.46.2 | ? unknown | |
| Warp | ? unknown | ||
| Cursor | ? unknown | ||
| Terminal.app | ? unknown |