This project is a human-guided, largely AI-executed workflow.

A work-in-progress, byte-exact and reassemblable disassembly of Alpharoid (アルファロイド / αROID, 1986) for the MSX — a 32 KiB unmapped cartridge by Opera House, published by Pony Canyon.

The goal is a readable, commented, buildable source that reproduces the original ROM exactly, so the game can be understood and modified.

Alpharoid.asm    master: one PHASE 4000-BFFF, INCLUDE banks/banks_0123.asm
Alpharoid.sha1   SHA-1 of the 32 KiB ROM (`make verify`)
banks/           linear window banks_0123 plus ram/bios/gfx includes
tools/workbench/ MSXDAW submodule (regen, romscan, gfx, PSG)
docs/            reverse-engineering notes (`game-notes.md`, `progress.md`)
gfx/             labelled PNG contact sheets (`make gfx`)
music/           labelled BGM WAVs (`make music`) — two-channel ids 1..5
sfx/             labelled SFX WAVs (`make sfx`) — channel-A song_tbl fragments
Makefile         build / verify

You need sjasmplus, built from source (z00m128/sjasmplus) and placed at tools/sjasmplus. No original ROM and no MSXDAW workbench checkout are required to assemble or verify. (make banks / make coverage and bank regen use the tools/workbench submodule.)

make skills     # tools/workbench/bin/install-skills -> .cursor/skills/
make verify     # assemble, then SHA-1 check against Alpharoid.sha1
make coverage   # local Shields JSON under generated/badges/
make gfx        # PNG contact sheets under gfx/
make music      # BGM WAVs under music/
make sfx        # SFX WAVs under sfx/

make alone produces Alpharoid.rom in the repo root (gitignored). Alpharoid.sha1 is the SHA-1 of the 32 KiB MSX ROM; make verify rebuilds and confirms the output matches it.

32 KiB = 4 × 8 KiB banks, always mapped at CPU 4000-BFFF (no mapper), one window file banks/banks_0123.asm. After every change the ROM is rebuilt and SHA-1 checked so it stays byte-for-byte identical.

See docs/game-notes.md for reverse-engineering notes and docs/progress.md for current status and next steps.

Comments, labels, tools, and repository structure are Apache 2.0 (see LICENSE and NOTICE). The original game is © 1986 Pony Canyon / Opera House and is not relicensed.