Sometimes the Gameshark will lock itself up, in this case it helps if you put a 6102 game into the Gamesharks slot and then put both into the Cart Reader and just start dumping the rom as if it was a game.
For some reason I can only read or write the first 128KB while the second 128KB remain 0x00.
You might have to re-calculate your homebrew rom's checksum if you had to trim it down to 128KB. In this case you can use chksum64.exe out of the libdragon devkit. Not sure if this is needed though.
And yes by "SST29LE010 N64 Repro" I'm jokingly referring to the Gameshark.
I wanted to turn the Gameshark into an import adapter using Lac's boot emu but the boot emu just restarts itself since the Gameshark isn't switching to the top cart slot.
Sometimes the Gameshark locks up, then you have to plug a 6102 cartridge into the Gamebuster's top slot and then connect both to the cart reader and read the rom. After that it should be accessible again.
Don't use this to update your working Gameshark since you can't read nor write the whole 256KB right now.
But if you have a broken one, have fun. :)
I tested this with a Gameshark V2.0
If you're still using the old 16bit adapter(the one with the additional pins left and right on the snes cart edge) you can enable the menu again by changing one line in Cart_Reader.ino:
// Enable 16bit flash adapter menu
#define enable_flash16
Some cartridges might have differing versions depending on the region they were released to. In most cases, the IC identifies as something else not presently covered by the current code, but they are ABI compatible with the existent FlashRAM supported types.
This will add support for 29L1100KC-15B0 compatible ICs like the MX29L1101.