sl40edit

A terminal channel list editor for the Comag SL40HD satellite receiver, for Linux.

The SL40HD can back up its channel database to a USB stick (DB management → Backup to USB), but the receiver's own menus make reordering hundreds of channels tedious. sl40edit opens that backup, lets you reorder channels with the keyboard, and writes it back, ready for Load from USB.

┌ sl40edit — /media/sdc1/COMAG_SL40HD_03_11.DBM [+] ───────────────────────────────────────────┐
│     # Name                                        Satellite                     Freq  Pol  SR│
│     1 Das Erste HD                                ASTRA 1H,1KR,1L,1M 19.2°E     11493 H 22000│
│  »  2 ZDF HD                                      ASTRA 1H,1KR,1L,1M 19.2°E     11361 H 22000│
│     3 AnixeHD Serie                               ASTRA 1H,1KR,1L,1M 19.2°E     10773 H 22000│
└──────────────────────────────────────────────────────────────────────────────────────────────┘
 MOVING  2/378 · modified · j/k g/G move · / n N after match · space drop · esc cancel · ? help

Status

Works and has been tested on a real receiver: lists reordered with sl40edit load via Load from USB and show the new order.

Supported: the 948,368-byte .DBM backup of the Comag SL40HD. Other receivers or file sizes are rejected on load. Other MStar-based receivers that write the same layout (ChanSort lists e.g. the Xoro HRS 8520) may work but haven't been tested.

Not yet supported: deleting or renaming channels, favourite lists, the hide/skip/lock flags. The file layer keeps every byte intact, so these can be added later.

Install

You need a Rust toolchain (1.88 or newer), e.g. from rustup.rs.

git clone https://github.com/blangguth/sl40edit
cd sl40edit
cargo install --path .

Usage

1. On the receiver: DB management → Backup to USB. This writes a file such as COMAG_SL40HD_03_11.DBM to the stick.
2. Plug the stick into your computer and run:

   sl40edit /media/<stick>/COMAG_SL40HD_03_11.DBM

3. Reorder, press w to save, q to quit, then run sync before unplugging.
4. On the receiver: DB management → Load from USB. The receiver accepts the dated filename as is.

The first save keeps your original as COMAG_SL40HD_03_11.DBM.bak next to it. Later saves never overwrite that backup.

Keys

Key
j/k, ↓/↑, PgDn/PgUp, ctrl-d/ctrl-u, g/G	move the cursor
space	grab a channel. Movement keys then move it, space drops it, esc cancels
m	move the channel to a position number
/	search. Matches as you type, ignoring case, accents and punctuation (sat1 finds "SAT.1 Gold"). ↓/↑ step through matches, enter keeps the result, esc goes back
n / N	next / previous match
/, n, N while moving	place the grabbed channel right after the matching channel
u / ctrl-r	undo / redo
w	save
q	quit (asks again if there are unsaved changes)
?	help

A quick way to build your order from the top down: grab a channel, type / and the name of the channel it should follow, press enter, then space.

Receiver test mode

sl40edit --test-swap FILE.DBM

Swaps channels 1 and 2 and saves (with the same .bak handling). Useful to check that your receiver and firmware accept files written by sl40edit. Run it again to swap back.

Safety

• The file is validated on load: exact size, plus the checksum the receiver uses. Anything else is refused.
• Reordering changes only the program-number field of each channel record and the checksum. All other bytes are copied unchanged.
• Before writing, the new file is parsed again and checked. It's written to a temporary file first and then renamed into place.
• If the file on disk changed after you opened it (for example, you made a new receiver backup in the meantime), w refuses to overwrite it.

Still: this is an unofficial tool. Keep your original backup.

File format

The layout of the SL40HD .DBM file comes from ChanSort by PredatH0r (GPLv3), section [dbm:948368] of ChanSort.Loader.DBM.ini. It was verified against a real backup and extended (orbital position, polarisation). See SPEC.md for the field-by-field description and design notes.

Development

cargo test
cargo clippy --all-targets

Most tests need a real receiver backup, which isn't included because it's a personal channel list. Put an unmodified SL40HD backup at testdata/COMAG_SL40HD_03_11.DBM (read-only). Without it, those tests skip. Several tests check the specific contents of the author's backup, so with a different file some of them will fail.

License

Copyright (C) 2026 Benjamin Langguth

GPL-3.0-only (GNU General Public License, version 3). See LICENSE.

This project is not affiliated with or endorsed by Comag. "Comag" and "SL40HD" are used only to identify the supported device.