Gens KMod & $E00000-$FE0000?

cdoty · Post by **cdoty** » Fri Dec 15, 2006 3:58 am

Does Gens KMod treat locations $E00000-$FEFFFF as VRAM?

I ran Puckman Pockimon through the emulator, and the messages seem to indicate that it was transferring from VRAM to VRAM.

Spy : 68k -> VRAM of 32768 bytes from E00000 to 0000 (VRAM access)

and

Spy : 68k -> VRAM of 320 bytes from FEF000 to F000 (VRAM access)

Stef · Post by **Stef** » Fri Dec 15, 2006 7:26 am

$E00000-$FEFFFF as VRAM ??

This area is recognized as main ram in Gens and i think it's the same for Gens KMod.

cdoty · Post by **cdoty** » Fri Dec 15, 2006 6:34 pm

Ok, I think that makes sense..

The Puckman Pockimon board seems to limit the address that the VDP can use.

Location 0xE00000 is the location of the ROM, and Location 0xFEF000 is Ram, to the VDP.

So, in DMAing from ROM to VRAM, it would need to add 0xE00000 to the value.

Ironically, the game works correctly under kGens, minus the issues with input and dip switches.

Stef · Post by **Stef** » Thu Dec 21, 2006 5:29 pm

It's really strange that despite the big difference in ROM location (E00000 versus 000000 on genesis) the game pseudo run on KMod.
I guess you did some modification to adjust the memory map in KGens right ?

cdoty · Post by **cdoty** » Wed Dec 27, 2006 7:30 am

Stef wrote:I guess you did some modification to adjust the memory map in KGens right ?

Nope, played without any changes to KGen. Maybe the addresses are masked on something...