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

A work-in-progress, byte-exact and reassemblable disassembly of Konami's Vampire Killer (Akumajō Dracula, 1986) for the MSX2 — a 128 KiB Konami MegaROM (Konami4, no SCC).

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

You can find random interesting facts from the disassembly at @msxti.me on Bluesky.

VampireKiller.asm   master file: stitches paging windows into the ROM image
VampireKiller.sha1  SHA-1 of the original 128 KiB ROM (`make verify`)
segments/           one file per paging window (fills through 0xC000)
  banks_0123.asm    banks 0-3: resident + play (32K @ 0x4000)
  banks_456.asm     banks 4-6: tileset window (24K @ 0x6000)
  banks_78.asm      banks 7-8: late tilesets / HUD font / ending
  banks_9a.asm      banks 9-a: title gfx / palettes / enemy RLE
  banks_bcd.asm     banks b-d: map tables / metatile defs / transitions
  banks_ef.asm      banks e-f: scenery / PSG / Dracula portrait
  data/             metatiles, tilesets, fonts, 1bpp sprite RLE, PSG, gfx scripts,
                    scenery/spawn/object lists, conn/door/spot tables
  actors.inc etc.   small numeric ids (actor/item/weapon/sfx/pose/scenery/event/state/dir)
tools/              game-specific helpers (gfx sheets, maps, PSG)
  workbench/        MSXDAW submodule (regen, romscan, RLE, PSG)
docs/               reverse-engineering notes (`game-notes.md`, `vendor.md`, `progress.md`, `unused.md`)
gfx/                readable graphics catalogue (PNG sheets committed; `make gfx`)
                    sprites/ packed 1bpp sprite-asm sheets; tilesets/ 4bpp
                    playfield/title; palettes/ palette_apply swatches;
                    metatiles/ 4x4 def sheets and 8x6 room streams; fonts/ 1bpp glyph sheets;
                    composites at gfx/ root (`stage_sNN.png` annotated playfields,
                    `minimap_sNN.png` schematic layouts)
music/              BGM catalogue (WAV; `make music` from the ROM bytecode;
                    recognizable, not fully hardware-accurate yet)
sfx/                SFX catalogue (WAV; `make sfx`; `05_whip.wav`, etc.)
Makefile            build / verify

All banks assemble from labeled .asm (no leftover .bin). Tilesets, gfx scripts, RLE, and PSG assemble from labeled .asm; tools/emit_identified_data.py regenerates those dumps from a ROM image.

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 gfx / make music / make sfx and bank regen use the tools/workbench submodule.)

After a clone with the submodule, link generic agent skills into this repo (not ~/.cursor/skills):

make skills     # tools/workbench/bin/install-skills -> .cursor/skills/
make verify     # assemble, then SHA-1 check against VampireKiller.sha1
make coverage   # local Shields JSON under generated/badges/

make alone produces VampireKiller.rom in the repo root (gitignored). VampireKiller.sha1 is the SHA-1 of the original 128 KiB MSX2 ROM; make verify rebuilds and confirms the output matches it.

128 KiB = 16 × 8 KiB segments (Konami4 mapping). Segment 0 is always resident at 0x4000-0x5FFF; segments are converted from raw binary into commented disassembly one at a time, and after every change the ROM is rebuilt and SHA-1 checked so it stays byte-for-byte identical.

Text is stored as ASCII - 0x10 (HUD/title) or plain ASCII (credits); the vk / cr macros in VampireKiller.asm let strings be written as readable ASCII while emitting the exact original bytes (space → 0x00).

Graphics: uncompressed playfield tilesets are hex defb (one 4-byte row per scanline). Sprites stay RLE-packed in source (tools/workbench/konami/rleenc.py is not byte-exact). make gfx writes PNG previews from the ROM, including gfx/enemy_sheet.png and a full-frame sheet per enemy (gfx/sheet_enemy_zombie_01.png, …). Packed 1bpp sprite asms dump to gfx/sprites/<stem>.png. Orphan / unused slices: gfx/sprites/unused_*.png, gfx/tilesets/unused_tiles.png, gfx/unused_poses.png. Spawn bitmask rooms: gfx/spawn_generators.png. Unused 16×16 scenery block: gfx/unused_block16.png (docs/unused.md). Each 4bpp tileset asm has a sheet at gfx/tilesets/<stem>.png. Each palette_apply asm has a sheet at gfx/palettes/<stem>.png (16 columns = VDP index; cell header = CPU address of the 3-byte record). Each metatile-def table has a sheet at gfx/metatiles/<stem>.png (4×4 tiles, cell header = CPU address of the def). Room streams are gfx/metatiles/mtile_streams.png (one stage per row) and gfx/metatiles/mtile_stream_intro.png (cell header = CPU of the 48-byte stream). gfx/stage_sNN.png is the annotated playfield composite (roomperm.py --composite; rooms, scenery, enemies, vendors). gfx/minimap_sNN.png is the schematic F2-minimap layout.

See docs/game-notes.md for reverse-engineering notes, docs/vendor.md for the vendor / difficulty-tier map, docs/unused.md for leftover ROM assets, and docs/progress.md for current status and next steps.

Original work in this repository (tools, comments, documentation, labels, and project structure) is licensed under the Apache License, Version 2.0. See LICENSE and NOTICE.

Vampire Killer (Akumajō Dracula) is © 1986 Konami. This project does not relicense the original game, ROM, graphics, or music.