CSB Technical Reference

Chaos Strikes Back (CSB) Technical Reference

Scope

CSB uses ReDMCSB as its main reference and CSBWin for CSB-specific save, DSA, champion, and input behavior. Launch needs hash-verified CSB graphics and dungeon data; missing title, entrance, door, or HUD art is not replaced.

Startup and Dungeon

PRESENTS, CHAOS, STRIKES BACK, entrance, door opening, and HUD handoff are typed indexed-raster phases with independent palette/timing contracts. They are not recolored DM1 assets. M12 passes a verified package session to M11.

The M10 F0267 route owns live loaded Thing chains, including cross-level pit and teleporter movement. It preserves source-tail ordering and restores the prior current-level context after a transfer.

CSBWin DSA Boundary

Extended-save actions are checksum-authenticated and retain source (dsa, state, ordinal) identity. Supported pure stack execution is transactional: LOAD/STORE, local/global banks, and bounded JUMP/GOSUB transfer chains use the first source-file-order (state,column) match. Type-47 DSAselector resolves through authenticated DSALevelIndex[level][selector] data.

Forged actions, malformed extensions, unknown IDs, transfer/depth limits, and world-mutating opcodes reject before state publication. This is deliberately not a claim that every CSBWin opcode, ProcessDSAFilter path, or EXPOOL class is implemented.

Save and HUD Ownership

Save imports stage GAMEBLOCK, champions, items, timers, extensions, and trace data before committing. The CSB raster boundary owns title, entrance, door, and HUD palettes; unresolved skin/EXPOOL data cannot become substitute pixels.

Verification

cmake --build build --target test_csb_v1_phase7_verification \
  test_csb_v1_dsa_trigger_single_step_pc34_compat --parallel
./build/test_csb_v1_phase7_verification
./build/test_csb_v1_dsa_trigger_single_step_pc34_compat

For authenticated DSA, actuator, save, and raster contracts, see CSB DSA and Save Internals.