Files
TeslaRel410/emulator/vpx-device
CydandClaude Opus 4.8 57524d4a68 Phase 3c: fix production vr_sync abort; full game runs through renderer
Root cause: vpx_max_postboot_acks=200, a Phase-2 bring-up guard, capped how
many post-boot replies the device would ever feed. A real BattleTech session
issues an unbounded stream of sync/frame/render replies and aborted with
"velocirender_receive timed out - sends_wo_rcv" at exactly the 200th ack
(143 sync + 55 frame-ack + 2 render). Cap is now effectively unlimited
(0x7fffffff; override VPX_MAX_ACKS for diagnostics).

After the fix the full game (game.conf, RIO disabled, cycles=max) runs
indefinitely: 2500+ syncs, 1264+ frame-acks, no abort, into L4VIDEO content
load (Thor mech + terrain from ALPHA_1/REL410/BT/VIDEO/GEO -- 841 real .bgf
models; test.egg is only mission params). Window still shows background:
the game uses the full DPL hierarchy (instance/object/lod/geogroup + DCS
transforms) which the flat flyk-tuned scene walk doesn't traverse yet -- that
is Phase 3d, documented in PHASE3-PROGRESS.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-03 14:45:20 -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.