# T-Modem-c1224 — max25d device (`tmodem`)

**AS-IS** · prototype · English only.

## Role

[T-Modem-c1224](https://github.com/ngteq/T-Modem-c1224) Pico firmware presents **USB CDC KISS** (half-TNC: HDLC on Pico, AFSK on TCM3105-class chip). max25d talks **raw KISS** on `/dev/ttyACM*` — same family as `kiss-raw-serial` / `baycom-kiss` serial path, but **not** BayCom/based and **not** SER12.

## Enable

```ini
[features]
tmodem = yes

[devices]
default = tmodem
tmodem = /dev/ttyACM0

[serial.tmodem]
baud = 115200
line = 8n1
dtr_rts = no
```

Example file: `share/max25/max25d.tmodem.ini.example`.

## Terminal

```bash
max25-terminal -d tmodem
# or SET DEVICE tmodem after connect
```

## RX before TX

Any on-air smoke: prove RX (noise / Soft-DCD / decode) before live TX. See `scripts/tx-rx-test.sh` and vault §0.20.

## HyBBX

Attach-only via a running max25d with `tmodem` enabled. No T-Modem L1 inside HyBBX.