512Kb.
Cheers
Have you seen this one? https://github.com/msolajic/c64-uni-cart Dunno about the price but they say the pcb is cheap at least. :D It seems like they have a converter for EF cart to magic desk format but not sure if it’s guaranteed right off the bat to work. Cheers
Hello
Maybe this can help? https://www.freepascal.org/~daniel/gmod2/
Alternative and easier way would be to just burn the EF if you have one. Cheers!