Unisystem VS games roms come in separate files, just as the EPROMs
on a real motherboard. Since I use only one EPROM, I must combine
all the rom files in a single one. It's easy, but the files must be combined
in the right order.
If you look at the Unisystem VS schematic
you will see that the roms are mapped in memory like this:
- 1D: $8000 to $9FFF
- 1C: $A000 to $BFFF
- 1B: $C000 to $DFFF
- 1A: $E000 to $FFFF
This means that they must be combined in the order D,C,B,A. Here is
how I do it under Linux:
# cat mds-sm4.1d > mds-sm4.bin
# cat mds-sm4.1c >> mds-sm4.bin
# cat mds-sm4.1b >> mds-sm4.bin
# cat mds-sm4.1a >> mds-sm4.bin
The same concept applies to the PPU roms: 2B comes first, then 2A.
NOTE: Dont bother asking me for the ROMS or where to get them, I wont reply.