# Multiple Area Transfer Mode (MATM)

> Whether one selected area or all of them is transmitted.

- **Sequence:** `CSI 15 h`
- **ECMA-48:** [§7.2.12 MATM – Multiple Area Transfer Mode, p. 24](https://archive.org/details/ecma-48-5th-edition-june-1991/page/n37/mode/1up)
- **DEC STD 070:** [§5.10.1.3 Modes That Cannot Be Changed, p. 5-134](https://archive.org/details/bitsavers_decstandar0VideoSystemsReferenceManualDec91_74264381/page/n388/mode/1up)

Mode 15 decides, when the terminal transmits its screen, whether only the
selected area the cursor is in is eligible, or every selected area.

| State | ECMA-48 calls it | Meaning |
| --- | --- | --- |
| Reset, `CSI 15 l` | SINGLE | only the area holding the cursor |
| Set, `CSI 15 h` | MULTIPLE | every selected area |

[DEC STD 070 §5.10.1.3, p. 5-134](https://archive.org/details/bitsavers_decstandar0VideoSystemsReferenceManualDec91_74264381/page/n388/mode/1up) lists it among the X3.64 modes a DEC terminal may treat as fixed,
as not applicable. The VT510 manual's [table of modes for DECRPM](https://vt100.net/docs/vt510-rm/DECRPM.html) marks it as always reset.

xterm ignores `CSI 15 h` and `CSI 15 l` ([`ansi_modes`](https://github.com/ThomasDickey/xterm-snapshots/blob/xterm-411a/charproc.c#L7399-L7424) handles only modes 2,
4, 12 and 20), and [DECRQM](https://control-codes.page/csi/decrqm/index.html.md) reports the mode as permanently
reset, `4` ([`do_ansi_rqm`](https://github.com/ThomasDickey/xterm-snapshots/blob/xterm-411a/misc.c#L5408-L5463)). libghostty-vt ignores it too, but does not recognize the
number, so it answers DECRQM with `0`. Both DECRQM cases are known
differences.

## Validation

### MATM-1: Reported as permanently reset

*A known difference: libghostty-vt does not pass this case.*

Input, one step per line:

```text
\e[15$p
```

Expected screen:

```text
|_____|
reply \e[15;4$y
```

### MATM-2: Even after it is set

*A known difference: libghostty-vt does not pass this case.*

Input, one step per line:

```text
\e[15h
\e[15$p
```

Expected screen:

```text
|_____|
reply \e[15;4$y
```

---

This is the Markdown version of <https://control-codes.page/ansi/matm/>. On that page every validation case runs live in libghostty-vt, the terminal emulation core of Ghostty, compiled to WebAssembly.

The validation cases are written in the notation described in <https://control-codes.page/notation/index.html.md>.