Skip to content

compatibility.md

Latest commit

 

History

History
55 lines (40 loc) · 2.57 KB

compatibility.md

File metadata and controls

55 lines (40 loc) · 2.57 KB
Raw

Compatibility — RustySNES

References: docs/STATUS.md (the authoritative board matrix); ref-docs/research-report.md "Scope and goals"; ref-docs/2026-06-24-coprocessors.md.

This doc records which hardware revisions, regions, and software families are in scope and known incompatibilities. The live per-board / per-suite matrix lives in docs/STATUS.md — this file is the prose context for it.

In scope (v0.1+ accuracy target)

Per ref-docs/research-report.md "Scope and goals":

  • Regions: NTSC and PAL (and Dendy-equivalent timing) as data, not a build fork — the master-clock frequency + scanline-length variants are region constants (docs/scheduler.md).
  • CPU: WDC 65C816 (5A22), emulation + native modes, the full DMA/HDMA controller, multiply / divide units, H/V-IRQ timers, NMI, joypad auto-read.
  • Video: PPU1 + PPU2, BG modes 0–7 (incl. Mode 7 affine), the 128-sprite OAM model, CGRAM/VRAM, color math / windows, the dot-clock timeline.
  • Audio: SPC700 + S-DSP + 64 KiB ARAM, 8 voices, BRR, the async clock domain.
  • Carts: LoROM / HiROM / ExHiROM (+ ExLoROM), header auto-detection, SRAM / battery saves.
  • Coprocessors: the families in docs/cart.md, tiered Core / Curated / BestEffort.

Coprocessor tiers (the compatibility shape)

Per ref-docs/2026-06-24-coprocessors.md §C and docs/adr/0003:

  • Core / Curated (verified, back the oracle): DSP-1, Super FX / GSU-1/2, SA-1.
  • BestEffort (functional, never inflate the accuracy number): DSP-2/3/4, S-DD1, SPC7110, CX4, OBC1, ST010/011, ST018, S-RTC.
  • Chip-ROM-dump dependence: the LLE chips (DSP family, ST01x, CX4, ST018) need the user to supply dumped chip program ROMs — feature-gated with a loud honesty caveat; without the dump the board is non-functional.

Out of scope initially (documented, deferred / BestEffort)

Per ref-docs/research-report.md "Scope":

  • Satellaview (BS-X) modem, Sufami Turbo, Super Game Boy pass-through emulation.
  • SNES Mouse / Super Scope niche peripherals beyond a stub.
  • Exotic flash-cart mappers.

Known determinism caveats

  • SPC resonator drift (±0.5%) is excluded from the deterministic core; a real game that relies on per-console drift will play deterministically but not bit-match a specific physical unit (docs/apu.md §determinism-caveat).
  • RTC chips (S-RTC, SPC7110's RTC-4513) read frozen / seeded time, not host wall-clock (docs/adr/0004).

Open questions

  • The precise commercial-title compatibility list fills in during Phases 4 / 6 / 7 as boards land; track it in docs/STATUS.md, not here.