Please avoid buying bootleg cartridges. Doing so encourages not homebrew development, but copyright infringement. Their hardware details are listed for people who ended up with bootleg cartridges already, as well as for documenting the history of the WonderSwan aftermarket hardware scene.

There is reason to believe that a non-bootleg reflashable cartridge solution will be available soon. Please stay patient.

Notes:

• “Re-flashable?” terms:
  • “Self” - the WonderSwan alone is sufficient to flash the cartridge. One can use BootFriend to reflash such a cartridge.
    • Be careful - if the cartridge is re-flashed without a valid cartridge header, the console will not turn on with it inserted again!
  • “USB” - the cartridge includes a USB port which can be used for flashing.
  • “External” - external device required. This does not include hardware which has an edge connector or pinout for manufacturing use only.
  • “?” - not fully tested, most likely it is “Self” that is unknown.
• Cartridges marked in Bold are currently manufactured (as of writing).

• The “Due to hardware limitations” compatibility list is outdated and inaccurate. Software flaws in the official menu software caused many of the incompatibilities.
• Flash Masta rev4 uses a genuine Bandai 2003 chip, rev5 uses a re-implementation - details unknown.
• Until August 2023, the price was $100 (with the occasional 10-20% off sale).
• The SD card port available on the Flash Masta rev4 is non-functional - it's wired up to the AVR chip, but there is no way exposed to use it on production firmware.

• WS Flash Masta flashing software
• CartFriend unofficial WS-side menu software - highly recommended

• The GBxCart with an edge adapter is required to flash this cartridge.

• Product page - contains flashing and save management software

• WonderMagic Color flashing software