PCE / PCE CD

---
description: PCE / PCE CD emulator — architecture and debugging
globs: Core/Src/porting/pce/**,linux/pce/**,retro-go-stm32/pce-go/**
alwaysApply: false
---

# PCE / PCE CD

When editing or debugging PCE code, read and follow **Core/Src/porting/pce/CLAUDE.md** in full.

Quick pointers:

- **Linux harness:** `cd linux && make -f Makefile.pce` (play) or `make -f Makefile.pce debug` (trace/self-tests).
- **Savestate padded layout:** SVARs at byte 13, then pad to 76 KB, then CD RAM — never `fseek(76KB)` before SVARs (Valis II freeze).
- **ADPCM:** `pce_adpcm_sync()` on status polls (`$1800`, `$1803`, `$180A`, `$180B`, `$180C`) + per frame; not every `$180x` read.
- **Arcade Card:** `PCE_ENABLE_ARCADE_CARD`; phys reads need `(MMR[page]<<13)|(addr&0x1FFF)`.
- **Low CD volume:** `grep FADER pcecd_diag.txt` — stuck fader after `$180F` fade without `CANCEL`.