_{Final Fantasy is a trademark of Square Enix. NES is a trademark of Nintendo. ColecoVision and every other name mentioned here belong to their respective owners, who have nothing to do with this project. This is an unofficial, non-commercial fan port that contains no game data. Trust is good; not trusting is better: check the hashes, read the code, build it yourself.}

coleco-ff

Final Fantasy (NES, 1987) rewritten in C for the ColecoVision, with the Super Game Module and a 512 KB MegaCart. As far as we know, nobody has done this before.

The NES game is the specification. Disch's commented disassembly is treated as an executable description of what the game does, and the port reimplements it in C on a Z80 with 1 KB of stock RAM. It does not translate the 6502 code. The data is the NES data, extracted from your own ROM at build time. The rules are the NES rules too, with one set of deliberate exceptions: the known bugs of the original are fixed, and each fix is documented.

No game data is included. To build a ROM you need your own copy of Final Fantasy (USA). See Building.

---

Status

Development snapshot slice78. The target is the first arc of the game: from power-on to the King's bridge and the "FINAL FANTASY" title card that appears when you cross it.

Area	State
Opening legend, boot menu, class select	✅
Overworld: discrete tile movement, collision, full-colour tiles, random encounters over the whole map	✅
Coneria, Coneria Castle 1F/2F, Temple of Fiends: maps, teleports, NPCs, dialogue from the ROM	✅
Shops: weapon, armor, white and black magic, item, inn, clinic (buying only)	✅
Battle: physical attacks, enemy AI, magic on both sides, ailments, buffs, EXP, levels, NES formulas	✅
Menu: items, magic outside battle, equipment, status	✅
Quest: King, Garland, Princess, Lute, the bridge, the bridge scene	✅
Treasure chests, DRINK/ITEM in battle, RUN odds, Game Over, name entry, saving	⏳ see ROADMAP.md
Battle animations (weapon swings, spell effects)	⏳

Validated in emulation only. The regression suite drives MAME (-exp sgm) through 13 scripted runs and checks the result from RAM and VRAM: 560 checks, all passing at slice78. One run, bridge, failed once in seven executions and could not be reproduced; making it closed-loop is on the roadmap. CoolCV is used for listening tests. This code has never run on real hardware.

Only part of the quest is validated end to end. The quest run and the bridge run each start from a build that seeds the party or the bridge flag. A single unseeded playthrough in one ROM is the next milestone.

Hardware target

• ColecoVision + Super Game Module. FF1 needs about 10 KB of RAM, and the stock console has 1 KB. The SGM adds 24 KB, and its AY-3-8910 plays the triangle channel next to the SN76489.
• MegaCart, 512 KB (32 banks of 16 KB). The last bank is fixed at $8000-$BFFF and holds the engine and the services. The other banks are switched in at $C000-$FFFF. Some hold data (maps, graphics, monsters, music). Others hold code overlays: battle, magic, menu, shops, dialogue, intro and the bridge scene, each entered through svc_run_overlay. The bank map is in one place, at the top of tools/build_all.ps1.

Building

Everything runs on Windows with the built-in Windows PowerShell 5.1.

What you bring

	Where it goes
Final Fantasy (USA) NES ROM, .nes with or without the iNES header. The importer checks it: PRG CRC32 CEBD2A31.	anywhere; you pass the path
Disch's Final Fantasy disassembly (the "Final Fantasy Disassembly" folder, usually distributed as FF1Disassembly-master). Some extractors parse its .asm and .tbl files.	FF1Disassembly-master/Final Fantasy Disassembly/
z88dk v2.4 for Windows (z88dk-win32-2.4.zip)	unzipped to z88dk/z88dk/
To run it: MAME (coleco driver, with your own ColecoVision BIOS in mame_roms/coleco/) or CoolCV	MAME via $env:MAME or tools/local.ps1

Two commands

.\tools\import_assets.ps1 -Rom 'C:\path\to\Final Fantasy (USA).nes'
.\tools\build_all.ps1

import_assets.ps1 checks the ROM and the disassembly against each other, then runs every extractor. This generates about 45 headers and blobs: tiles and colours, maps, monsters, music, text and game tables, all under src/ and build/, and all ignored by git. build_all.ps1 compiles the data banks, the main program and the eight overlays, in the order they depend on each other. The result is build/slice78_mc512.rom.

The build is deterministic. A clean clone built from the same ROM gives the same bytes every time.

Running

mame coleco -exp sgm -cart build\slice78_mc512.rom      # -exp sgm is mandatory
.\tools\build_all.ps1 -Run                               # opens CoolCV, if present in CoolCV\

Controls: joystick and the two fire buttons, as on the NES. The keypad adds shortcuts: 1-4 pick a party member directly, and * confirms.

Testing

.\tools\run_regressions.ps1                 # all 13 runs, about 15-20 minutes
.\tools\run_regressions.ps1 -Only quest     # one run

Each run compiles its own ROM and drives MAME headless with a Lua script from tools/mame_drive_*.lua. Test builds that seed state use -Defines and are named *_t.rom, so they cannot be mistaken for the real ROM.

Repository layout

Path	What
src/slice78.c	The main program: fixed-bank engine, services, overworld, map engine
src/ovl_*.c	Code overlays, one per switchable bank (battle, magic, menu, shops, talk, intro, bridge)
src/*_bank.c	Data banks. They only include generated headers and export pointers
src/*.h	Engine state (party, battle, world, shops) and the service ABI (svc_api.h)
crt/	Startup code for the MegaCart, the data banks and the overlays (derived from z88dk)
tools/import_assets.ps1	BYOA: every extractor, with the arguments the build needs
tools/extract_*.ps1, ff1_extract_song.ps1	The extractors
tools/build_all.ps1, run_regressions.ps1	Build and test
docs/	Design notes: deviations from the NES, battle engine, NES→TMS9918 colours

The project grows in slices: each one is a complete copy of the main program one step further on. Only the current slice is in the repository. Some comments refer to design notes as [[name]]; those notes are the author's private working log and are not included.

Credits

In the game, Square's copyright line is kept: on the boot menu, and on the title card that appears when you cross the bridge. Nintendo's line is removed from that title card on purpose. Nintendo published the NES version and has nothing to do with a ColecoVision port, so keeping its name there would credit it for something it did not do. tools/extract_bridge_scene.ps1 makes that choice (-DropNintendo, -DropSquare).

• Square, for the game.
• Disch, for the Final Fantasy disassembly. It is the specification this port is written against.
• z88dk, for the compiler and the ColecoVision startup code that crt/ builds on.
• AstralEsper, for the Game Mechanics Guide (GameFAQs), which is the reference for the battle formulas and for the list of NES bugs.
• FF Origins, for confirming spells, weapons and the NES bugs against the extracted tables. The site has lately been hard to reach; the Wayback Machine copy is the more reliable way to read it.
• Opcode Games, for the Super Game Module and MegaCart designs this port depends on.

Contributors: Samuele Voltan, and Claude (Anthropic), who pair-programs the port and co-authors its commits.

Licence

MIT for the original code and tools; see LICENSE, which also explains what the licence does not cover.