Zoom MS Doom CFW
Doom on a Zoom MultiStomp guitar pedal: a custom firmware for the MS-60B and MS-70CDR that boots straight into Doom (shareware episode 1) on the pedal's 128×64 LCD. Runs on the pedal's own TI C674x DSP at 300 MHz. No effects in this firmware — it is a separate one; flash a normal updater to get the pedal back.
Русская версия: README.ru.md.
Status: works on a real MS-60B (2026-10-28). The MS-70CDR has the same board and OS; not tried on one yet. No sound yet.
Safety and going back
The pedal's bootloader (flash 0x00000–0x3FFFF) is never written: the updater's bootloader steps are switched off. So you can always go back:
- Switch the pedal off, hold up + down (the effect type buttons), switch it on — the screen says FIRMWARE UPDATE.
- Run Zoom's stock
MS-70CDR v2.10updater (or the MS-60B one) — firmware and stock effects come back.
Close Ableton, browser tabs with Web MIDI and anything else using the pedal's MIDI port before flashing. Flashing takes noticeably longer than a normal update (the file system with Doom is written too).
Controls
| Control | In the game | In menus |
|---|---|---|
| D-pad up / down | forward / back | up / down |
| D-pad left / right | strafe | left / right |
| knob 1 | turn, 10° per click | left / right |
| knob 2 | previous / next weapon | up / down |
| knob 3 | automap on / off | — |
| knob 3 press (right) | fire | |
| knob 1 press, footswitch | use (doors, switches) | Enter |
| knob 2 press | menu (Esc) | Esc |
Always run. Keys are debounced; the knobs are read in the GPIO interrupt, like the stock OS does, so fast turns don't lose clicks.
Building
Needs (none of it is in this repository):
- TI C6000 code generation tools 8.5.0 (
cl6x, comes with Code Composer Studio) —TI_CGT_C6000; - Zoom's
ZOOM MS-70CDR v2.10 Updater.exe(zoom.co.jp) —ZOOM_UPDATER_70CDR, default: next topaths.py; doom1.wad, the shareware IWAD (1.9) —DOOM_WAD, default: next topaths.py;- Python 3.10+ with Pillow and numpy (only for the boot logo).
git clone --recursive https://github.com/Senty3kat/zoom-ms-doom-cfw.git
cd zoom-ms-doom-cfw
python -I build_cfw.py # -> out/DialUp-DOOM-ms70cdr-2.10.exe
The updater is Zoom's own, re-scripted by zoomms:
OS + logo + hook, and the file system with DOOM.BIN and the deflated WAD. The
bootloader steps stay off.
How it works
| Part | Where | What |
|---|---|---|
| hook | OS, 0xC00BB144 | the boot screen call goes to a trampoline at 0xC00F4000 → doom_hook |
| loader | shared RAM 0x80000000 (loader/) | boot logo; interrupts off; stops EDMA, McASP, USB; reads the file system over SPI0; inflates the WAD; jumps to Doom |
| Doom | SDRAM 0xC0000000–0xC03FFFFF | code, data, stack, heap (2 MB zone) |
| WAD | SDRAM 0xC03FF000–0xC07FFFFF | doom1.wad, inflated by the loader |
| screen | zd_lcd.h | own copy of the OS driver's ST7565 sequence (CS, D/C, PINMUX7) |
| controls | zd_pedal.c, zd_vectors.asm | buttons polled and debounced, encoders in the GPIO bank 1 interrupt (INT8) |
| files | pedal file system | DOOM.BIN (Doom's segments), DOOM.WDZ (WAD, deflate), empty FLST_SEQ.ZDT |
Doom itself is doomgeneric (submodule, unchanged)
plus zd_platform.c / zd_pedal.c. The 320×200 frame becomes 128×64: in a level only
the 3D view, sharpened, auto levels, error diffusion.
Developed and tested first in an emulator of the pedal (C674x CPU, McASP, SPI flash, LCD, USB MIDI, the real bootloader) before it ever touched hardware.
Not there yet
- Sound.
- Saving games (nothing is written to flash, on purpose).
Licence
GPL-3.0-or-later (LICENSE). doomgeneric is GPL-2.0-or-later, zoomms is MIT.
DOOM is a trademark of id Software; the WAD and Zoom's firmware are not included.