psxrecomp/docs/internal

Internal dev-logs & design notes

These are the working design documents and burn-down logs the project was built from. They are historical/working notes, not contributor onboarding docs — they capture decisions, phased plans, and deep subsystem investigations in the order they happened, and some sections are superseded by later ones.

If you're new here, start with the top-level README.md, then docs/ARCHITECTURE.md, docs/EXECUTION_MODEL.md, docs/BUILDING.md, and CONTRIBUTING.md. Come here when you need the why behind a specific subsystem.

Plans & roadmap

• PLAN.md — the original phased build plan (P1–P6).
• FAITHFUL_TIMING_PLAN.md — the authoritative cycle-accuracy north-star plan and status log.
• FIRST_MILESTONE.md — the first-boot milestone gate.
• STUBS_TO_FIX.md — hardware-stub burn-down (pre-game gate).

Cycle accuracy & timing

• PRECISE_IRQ_SLICE.md — exact-instruction IRQ delivery.
• CYCLE_MODEL_BEETLE.md — the Beetle-derived cycle model.
• ACCURACY_BURNDOWN.md — full accuracy burn-down across all axes (semantics, cycle, IRQ, MMIO, peripherals, determinism).
• COSIM_ORACLE.md — the first-divergence co-sim oracle.

BIOS / scheduler

• HLE_SCHEDULER_CARVEOUT_PLAN.md — the cooperative-thread scheduler HLE carve-out.
• WEDGE_load4_shell_rootcause.md — a specific boot-shell wedge root-cause writeup.

Renderer / widescreen

• GL_RENDERER_HANDOFF.md — OpenGL renderer design.
• NATIVE_WIDE_PLAN.md — native-wide 16:9 (GTE FOV) plan.
• BACKDROP_PRELOAD.md — widescreen backdrop preload.

Overlay cache internals

• SLJIT_PERSIST_CACHE.md — removed. It described the persisted shard cache of the sljit Tier-2 backend, which was deleted in 5b7e69b4 (2026-07-15). For the current model see runtime/src/overlay_loader.c (per-entry candidate validity), tools/compile_overlays.py (shard formation and the .ranges manifest), and ../COMPILING_OVERLAYS.md.