PC Engine dev forum

That's what my tests showed. I did writes to vram (ST1/2 opcodes), incremented a counter, and used the Timer interrupt to measure this for active display VS vblank area. I saw no difference in speed. Even with ST2 opcodes (writes to MSB only), the cpu can't saturate all the access slots of the VDC p...

Ahh ok, I see. It is. But, there's a possible incompatibility with old PCEAS generated code here; local label names used in high lever expressions. I added the ability to do .- and .+ (.+, .++, .---, .----, etc) for local labels. And you can use this just fine in expressions.. *IF* you use a space. ...

Did some of the PCEAS bugs get fixed as well? Specifically, the bug where if an opcode of more than 1byte, crosses a 8k page boundary.

The VDC has more CPU vram access slots during active display, then what the cpu can saturate. But if there's a slight out of alignment, the cpu will be stalled for a 'master clock' time slice. Of course, that's on the latch (MSB) and there's ~supposed~ to be a 1 word buffer as well. So to the progra...

This is great info. Thanks for posting this

No download link??

Have you thought about doing a tracer? It's part dissassembler and part cpu emulator. It basically starts from the reset vector, and follows every possible code path it can take. I started writing one many years ago, but it quick quite complex.

Can you give a small example code so I can look at it? Doesn't have to be your current game WIP code.

Ok, so what's the problem? CD_EXEC bios function won't load to bank $68 or $69 (00 or 01)?

No problem