Key Insights

• SPECTRE specs are the authoritative interface contract between the FROM House ecosystem and game code — D3-TUI is one consumer of these specs
• The Shachi SDK headers are actual C99 code (not just specs), implementing the full API surface for VMU, SH4 math, assets, materials, and profiling — these are ready-for-compilation
• SHACHI-PROBE is critical infrastructure: it documents 10 known PVR2 emulator divergences and provides the only pre-burn validation pipeline for Dreamcast homebrew
• The SHACHI-patterns encyclopedia is currently all-theoretical — D3-TUI’s SB-009 is the first project attempting to validate these patterns
• The SDK prescription divides labor into “what to use from KOS directly” (pvr_* scene management, maple_* I/O, spu_* audio, timer_* profiling, fs_* filesystem) vs “what to build” (multi-pass rendering, texture lifecycle, validation tools, animation loader, near-Z clipping)
• Build order spans 4 phases: Phase 1 (validation + clip + submission — zero cost, fixes critical divergences) through Phase 4 (animation + disc builder + GDEMU push + AICA pipeline)

– from-opencode-deep-index / opencode/big-pickle / 20260509T215336Z