Files
TeslaRel410/emulator/vpx-device
CydandClaude Opus 4.8 12d2952e9f VDB: palette-reload delta probe (test palette-animation hypothesis)
On each palette reload, diff against the previous captured palette and log how
many of the 256 entries changed plus the first few index:old->new. Confirms
the static/dynamic split: pal1/pal2 load once (static base structure -- red in
odd entries, etc.), pal0 is rewritten ~28x. In this capture pal0 is doing the
intro FadeToWhite -- ~216/256 entries ramping in lockstep from 0 to ~60/63 --
i.e. animating the whole display brightness via the palette without redrawing
the framebuffer. Selective per-element flashing (targeted small deltas) would
need an active mission to observe; this probe is the instrument for it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-03 20:31:51 -05:00
..

VPX device — DOSBox-X integration

Our original source for the emulated Division VPX link adapter. Kept here under version control because the DOSBox-X source tree itself (emulator/src/, ~490 MB) is git-ignored.

  • vpxlog.cpp — Phase 1 logging device. Impersonates the INMOS C012 link adapter at I/O base 0x150, answers status reads so the game keeps transmitting, and logs every access to $VPXLOG. (Phase 2 will grow this into a responding transputer-monitor + i860-loader + frame-stream renderer, or fork into a separate vpx.cpp.)

Applying to a DOSBox-X source checkout

Tested against DOSBox-X v2026.06.02, MSYS2 mingw64.

  1. Copy the device in:
    cp emulator/vpx-device/vpxlog.cpp  emulator/src/src/hardware/vpxlog.cpp
    
  2. Add it to the hardware build — in src/src/hardware/Makefile.am, append vpxlog.cpp to libhardware_a_SOURCES (we inserted it after glide.cpp).
  3. Call the init — in src/src/gui/sdlmain.cpp, declare void VPXLOG_Init(); next to the other *_Init() prototypes and call VPXLOG_Init(); right after GLIDE_Init(); in the machine bring-up sequence.
  4. Build:
    cd emulator/src
    ./build-mingw-sdl2 --enable-debug=heavy
    
    Output: src/src/dosbox-x.exe.

Running

set VPXLOG=C:\VWE\TeslaRel410\emulator\vpxlog.txt
emulator\src\src\dosbox-x.exe -conf emulator\capture.conf
python emulator\analyze_capture.py

With VPXLOG unset the device is inert and the build behaves like stock DOSBox-X.