The WS Flash Masta USB cartridge will accept 16 ROM files (one of which will likely be a menu) via USB and allow you to play them on your WonderSwan, WonderSwan Color, or SwanCrystal game console.
To upload ROMs to the cartridge, use the software found at http://www.flashmasta.com/software-downloads/. Most users will want to flash a ROM-selector menu to the first slot. This will allow you to select the other slots upon bootup.
Look closely at the product photo. That is what you will receive. This cartridge currently comes in a plastic shell, but it does not have a “Flash Masta” sticker. It may or may not come with a pre-attached sticker from an official game.
You can read more about this version (and previous versions) of the cartridge at our Wonderswan Flash Masta Cartridge forum.
As far as functionality goes, there are some items to be aware of. Not all ROMs work 100%. If you want to know more about what ROMs have problems, please see this forum thread about the v5.1 WS Flash Masta USB. Notice that some ROMs require a patch to work properly while a small percentage just fail to run. If any of the ROMs mentioned are of particular interest to you, I suggest that you post in that thread to see if anyone can provide more information.
Another item to make note of is that while the ROM area of the cartridge has 16 slots, the SRAM (gamesave) area does not have separate slots. This means that you can select different slots, but they will share the SRAM area. A game selection may overwrite other slot’s savegame data. Currently, playing a game may interfere with another slot’s savegame information. This may or may not be changed in the future.
If you are familiar with our previous WS Flash Masta USB cartridge (v4.4), this cartridge is intended to provide the same functionality. This 5.1 version of the cartridge is a redesign to make sourcing parts and manufacturing easier. This version also fits inside of a shell and does not require a battery to store gamesaves.