The Machine Indexan emulation field guide

1999 · Bandai · Japan · handheld

Bandai WonderSwan

After leaving Nintendo, Game Boy creator Gunpei Yokoi co-designed the WonderSwan with Koto Laboratory and Bandai.

Rewarding Trivial to run Watch on YouTube ↗

Bandai WonderSwan hardware
Bandai WonderSwan hardware

After leaving Nintendo, Game Boy creator Gunpei Yokoi co-designed the WonderSwan with Koto Laboratory and Bandai. Its single-AA battery ran for 40 hours, and its unique button layout allowed games to be played held either horizontally or vertically.

Squaresoft partnered with Bandai to release enhanced remakes of Final Fantasy I, II, and IV on WonderSwan Color before porting them to the Game Boy Advance.

Under the hood

CPU
NEC V30 MZ (16-bit 8086 compatible) @ 3.07 MHz with 16-bit internal architecture
Sound chip
4-channel digital audio with built-in voice sample playback
Graphics
FSTN reflective LCD (224 × 144), supports vertical (tate) and horizontal screen orientation
Media
WonderSwan Cartridges (Powered by a single AA battery for 30–40 hours!)

What it cost

¥4,800 1.7%

a rounding error against a month’s pay in 1999 · about $80 today

Japan launch price (¥4,800 / ~$40 USD) ¥4,800 (1999)

Gunpei Yokoi’s final handheld creation; ran for 30+ hours on a single AA battery.

Typical street price

No verified mass-market street price recorded yet.

Units sold3,500,000

3.5 million units sold across monochrome, Color, and SwanCrystal models.

Why it mattered

Squaresoft partnered with Bandai to release enhanced remakes of Final Fantasy I, II, and IV on WonderSwan Color before porting them to the Game Boy Advance.

Emulating it today

EmulatorsBeetle Cygne (libretro), Mednafen
Setup effortTrivial to run (0.5 on this site's scale)
ControlsA standard modern controller covers the ordinary controls, though unusual accessories may need custom mapping.
Runs on a handheldYes

Handled with precision by RetroArch Beetle Cygne and Mednafen cores. The emulator names above are starting points, not a promise that every title or accessory behaves identically. Computer platforms usually add model selection, disk handling and keyboard setup even when CPU emulation itself is mature.

WonderSwan Boot ROM (ws.bin)

Beetle Cygne and Mednafen include built-in open-source BIOS replacement code that boots WonderSwan games automatically. Supplying the original 4 KB ws.bin boot ROM provides the authentic Bandai logo splash screen and user profile setup.

How many files you need: 1. One optional 4 KB file: ws.bin.

Firmware details checked 2026-08. Emulator requirements change — see Libretro — Beetle Cygne documentation for the current list.

Where the software is

Preservation catalogues describe verified dumps; they do not grant permission to download commercial software. A curated, correctly matched set is easier to use than an undifferentiated archive.

This site names preservation projects and explains what they are. It does not link to ROM downloads.

Where to start

  1. Klonoa: Moonlight Museum Puzzle Platformer

    Namco’s charming dream-traveler platformer designed specifically for the WonderSwan.

  2. Final Fantasy I, II, & IV (WSC Remakes) JRPG

    The beautiful 16-bit visual overhauls that revitalized the classic FF series.

  3. Judgement Silversword -Rebirth Edition- Vertical Shoot 'em up

    Eschatos creator’s legendary vertical shmup played in vertical (tate) mode.

  4. Makaimura for WonderSwan (Ghosts 'n Goblins) Action Platformer

    Custom original Ghosts 'n Goblins adventure built from the ground up for WonderSwan.

  5. Gunpey Puzzle Action

    Addictive line-connecting puzzle game named in tribute to designer Gunpei Yokoi.

The verdict

Gunpei Yokoi’s final hardware design before his passing. Unique horizontal and vertical (tate) dual-orientation play and the original home of Final Fantasy I, II, & IV remakes and Klonoa:…

The strongest software can be rewarding, but original controls and setup assumptions may matter more than screenshots suggest.

Worth it if
Players curious about snk and bandai handhelds and willing to learn how the original machine worked.
Not for
Anyone who wants a large, instantly accessible library and no model, firmware or control decisions.

Scored 3/5 for fun today and 4/5 for historical importance. Those two scores decide the label at the top — a machine can matter enormously and still be no fun.