Cartridge Dumps

When you insert an original licensed cartridge inside the console and turn it on the system automatically dumps the cart content inside inside /mnt/asec/rom-xxxx.bin file, where xxx is a 16bit checksum located at offset 0x18E:

and it is calculated over ROM data as follow:

movea.l #$200,a0
   movea.l #ROM_End,a1
               move.l  (a1),d0
               moveq   #0,d1
               add.w   (a0)+,d1
               cmp.l   a0,d0
               bcc.s   loop
               movea.l #$18E,a1        ; Checksum
               cmp.w   (a1),d1
               bne.w   WrongChecksum

Unlicensed cartridges seems not to be dumped by the console for this specific reason (it is true that unlicensed games cannot be dumped but the reason why need to be verified).
32x games have the same genesis/mega drive pinout so, if you open the case (or cut the cartridge slot) you can also dump 32x games; you cannot fit a 32x cartridge inside the original unmodified console cart slot.