I haven't got a flash cart for the wonderswan, so I've been designing my own. Here's a couple of screen shots of the BIOS I'm designing. I built a flash programmmer to install the initial BIOS, updates will be uploaded via the EXT port on the wonderswan. pic.twitter.com/iKJJYR0LWB

— Kris Bleakley (@kjbleakley) August 8, 2019