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Doom 550D v0.3.0

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@lauris-nl lauris-nl released this 16 Jul 17:44
· 13 commits to main since this release
v0.3.0
acb4d8a

Doom 550D v0.3.0

This release was physically tested on a Canon EOS 550D with firmware 1.0.9.
It is the best playable build tested so far, with fluid gameplay, working
effects and stable low-CPU music.

Highlights

  • Play MUS music through a richer 24-voice, 24 kHz low-CPU synthesizer.
  • Mix music and Doom's original 8-bit effects into the 48 kHz camera output.
  • Use independent in-game music and sound-effect volume controls.
  • Hold zoom in (+) to run.
  • Hold zoom out (-) while pressing left/right to strafe.
  • Save directly with SET while retaining separate saves for every IWAD.

Stability and input fixes

  • Validate WAD cache ownership after loading saves, avoiding stale cache
    pointers and the Z_ChangeTag: block without a ZONEID module crash.
  • Reset queued camera input after a successful save, preventing controls from
    becoming stuck while music continues.
  • Intercept Delete/Trash as Doom Escape so it cannot open a hidden Magic
    Lantern menu over the game.
  • Avoid ISO, depth-of-field and shutter controls because Canon can process
    them before the module and display EOS overlays or steal input.
  • Preserve display, palette, input and audio cleanup across repeated runs.
  • Retain the commercial MAP01 intermission-name bounds fix.

Music backend

The synthesizer supports 24 voices, multiple inexpensive waveforms, General
MIDI instrument families, percussion, envelopes, channel volume and pitch
bend. It is designed to provide an AdLib-like retro sound without the CPU cost
that made the earlier cycle-level OPL2 experiments unstable on the 550D. It is
not cycle-accurate OPL2 emulation.

Audio timing is recorded in ML/LOGS/DOOM550D.LOG. The tested build reported
no missed audio deadlines during successful gameplay sessions.

Installation and compatibility

  • Target: Canon EOS 550D / Rebel T2i / Kiss X4, firmware 1.0.9 only.
  • Install as ML/MODULES/doom.mo.
  • Use a matching Magic Lantern autoexec.bin and 550D_109.sym.
  • Copy legally obtained Doom-compatible IWADs to ML/DOOM/.
  • Restart the camera after changing the selected WAD.

The required Canon audio stubs are already present in the documented Magic
Lantern base commit; no Doom-specific core modification is required. An older
Magic Lantern build must be replaced or rebuilt if its symbol file does not
export the audio functions listed in the README.

No WAD files or other copyrighted game assets are included.

Known limitations

  • The selector checks .wad plus the IWAD header but does not yet fully
    reject non-Doom games.
  • PWAD/mod loading is not implemented.
  • WAD switching requires a camera restart.
  • At most 32 IWADs are listed.
  • Multiplayer is not supported.
  • Logs retain only the most recent run.

Release binary

doom.mo
SHA-256: 1030f91aac3a622b4bfb86f9fe9244e1c28a730da7585f58d2a0e0113c50fc29
Assets 4
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