Data East converts / preservation¶
Data East (DECO) earns its page for the first arcade system with interchangeable games: the DECO Cassette System (1980), based on tape + dongle. It's the ancestor of everything the other "conversion" pages describe — and a preservation nightmare (magnetic tapes + modules that die). Data East later used custom protection chips (146/104/156).
| Field | Value |
|---|---|
| Platforms | DECO Cassette System (1980); DECO boards with custom protection |
| Type | tape + dongle (Cassette); ROM + ASIC (later boards) |
| Difficulty | 🟠 (tapes/dongles) |
| Suicide? | no battery, but fragile tapes + dongles |
DECO Cassette System (1980)¶
The first standardised arcade system letting the operator change game (well before JAMMA). Principle:
- The operator buys a base cabinet.
- Each game = a cassette (Microcassette) + a key module (dongle) in resin (anti-copy protection).
- At power-on the program is copied from tape into the cabinet's RAM (~2-3 minutes of loading).
-
Changing game = swap the cassette AND the dongle.
-
CPU: 6502-based (Data East DECO 222 variant, with encrypted opcodes on some).
- Dongles: several types over time (the security logic evolved by generation).
- End of life (1985): dropped due to tape and module unreliability (and uneven game quality).
Urgent preservation
Magnetic tapes (demagnetisation) + resin dongles (that fail) = a doubly fragile medium. The community dumped the tapes and dongles (security types) → MAME emulates the system. Imaging your living tapes is the priority.
Data East boards with custom protection (1990s)¶
On its 16/32-bit systems (DECO 16, Deco 32, MLC, Deco 156…), Data East used custom protection ASICs:
| Chip | Role |
|---|---|
| Deco 146 / 104 | protection (the program talks to the ASIC; address/data scrambling) |
| Deco 156 | encapsulated ARM CPU (later systems, encrypted data) |
- Games involved: Rohga, Captain America, Fighter's History, Dragon Gun, Night Slashers, Boogie Wings… and the MLC games (Skull Fang, Stadium Hero 96…).
- Converting these boards means handling the ASIC (the right custom, or code whose protection accesses are neutralised). The protections were reverse-engineered (MAME) → a base for preservation.
Program EPROM, game by game (1980s-90s JAMMA boards)¶
After the cassette, Data East moved to EPROM PCBs (68000, then ARM on DECO 32). Size →
EPROM: 64 KB → 27C512 · 128 KB → 27C010 · 256 KB → 27C020 · 512 KB → 27C040.
(Source: MAME dataeast/dec0.cpp, cninja.cpp, captaven.cpp, fghthist.cpp, dragngun.cpp,
rohga.cpp… Board view: Data East PCB.)
| Family | Game | Program EPROM |
|---|---|---|
| DECO (dec0, 68000) | Heavy Barrel | 6× 27C512 |
| Robocop | 4× 27C512 | |
| Bad Dudes vs Dragon Ninja | 4× 27C512 | |
| Sly Spy | 4× 27C512 | |
| Hippodrome | 4× 27C512 | |
| Bird Try | 6× 27C512 | |
| Midnight Resistance | 4× 27C010 | |
| DECO 16 (cninja) | Caveman Ninja / Joe & Mac | 6× 27C010 |
| Robocop 2 | 8× 27C010 | |
| The Cliffhanger: Edward Randy | 8× 27C010 | |
| Mutant Fighter | 4× 27C010 | |
| 68000 (others) | Dark Seal / Gate of Doom | 4× 27C010 |
| Crude Buster / Two Crude | 4× 27C010 | |
| Rohga | 2× 27C020 + 2× 27C040 | |
| DECO 32 (ARM) | Captain America | 8× 27C010 |
| Fighter's History | 2× 27C040 | |
| Dragon Gun | 8× 27C020 | |
| Locked 'n Loaded | 4× 27C040 |
Protection ASICs (60 / 104 / 146…) govern conversion
Many 1990s Data East boards have a custom ASIC (60/104/146…) that decrypts/protects the code: reburning the program isn't enough without the right game's ASIC. See the "custom protection" section above.
Settings (DIP)¶
DECO Cassette games and the classic boards are configured via DIP switches (difficulty, lives, free play, test). The settings follow the game: after a cassette/game change, refer to the target game's DIP table (see the general DIP convention).
Converting / preserving (summary)¶
- DECO Cassette: image tape + dongle (preservation); "changing game" = cassette + dongle of the wanted game.
- Protected boards: reprogram ROMs + handle the ASIC (Deco 146/104/156) — right custom or de-protected code.
Where to read more¶
- Wikipedia — DECO Cassette System (tape + dongle, boot to RAM, types) — https://en.wikipedia.org/wiki/DECO_Cassette_System
- MAME — drivers
dataeast/decocass.cpp(dongles),deco32.cpp,deco_mlc.cpp(Deco 146/104/156) — https://github.com/mamedev/mame
Sources & attribution¶
- Wikipedia — DECO Cassette System (1980, microcassette + resin module, copy to RAM ~2-3 min, dropped 1985) — https://en.wikipedia.org/wiki/DECO_Cassette_System
- MAME — Data East drivers (decocass / deco32 / deco_mlc, 146/104/156 protections) — https://github.com/mamedev/mame
Review & corrections
How this space is used
Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.
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