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It's sort of cheating, but I have first light for Sega 32X support in BlastEm. I say sort of cheating, because this demo does not use the SH-2s at all and instead just writes to the 32X VDP from the 68K. But hey, it's still progress. Should see some SH-2 code running soon

Game Sack

@gamesack.net

7 May

Does the 68K have access to the full 32X VDP? Or at least the colors?

Michael Pavone

@retrodev.com

The 68K has access to basically all of the 32X hardware except for SDRAM and the SH2 onboard peripherals. The VDP is very basic though, just a double buffered framebuffer with basic fill and overwrite functionality

7/5/26, 9:45 pm0 reposts0 likes

Game Sack

@gamesack.net

7 May

Ah, so everything basically has to be brute-forced by whatever CPU is accessing it? So for example, the scaling in Road Rash couldn't run any better if it used the 32X's VDP whilst still being controlled by the 68K?

Michael Pavone

@retrodev.com

7 May

A memory mapped linear framebuffer with 8bpp pixels is maybe a bit easier to do that sort of thing with compared to 4bpp tiles that you have to DMA to VRAM, but yeah there's no hardware acceleration for that. Fill can maybe be used to speedup flat-shaded polygons though