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1.0.2 ASCII16 cartridge for MSX works fine, Konami 1.0.2 cartridge returns black screen on Casio MX10

Open hexbus opened this issue 2 months ago • 4 comments

Hi, @visrealm!

I was testing the new Konami ROM for the @barbeque Konami (39SF040) cartridge board compiled with the new @nanochess CVBASIC Konami output method, and I seem to be getting a black screen on these PCBs. I'm able to run other Konami carts just fine, and I've even tried padding the output from 112K to 128K and putting four of these together and trying them in all switch positions - still get a black screen. The @rsbc Unimapper ASC16 ROM is still working fine, so I know your code seems to be OK, it's just the mapper output must be confusing the system somehow.

Thoughts?

hexbus avatar Oct 20 '25 12:10 hexbus

Looks like the answer is here in the CVBasic readme:

Image

CVBasic Konami mapper doesn't support bank switching. For now, I'll remove the Konami ROM.

visrealm avatar Oct 20 '25 23:10 visrealm

Or perhaps I'm reading that wrong. Perhaps in Konami mode, the banks are 8KB? instead of 16KB? The build has support for both bank sizes since TI99 has 8KB banks - just needs some testing.

visrealm avatar Oct 20 '25 23:10 visrealm

The Konami method should work and be compatible, as it switches dual 8 KB banks to keep a 16 KB bank-switching.

However, I noticed the 39SF040 chip is 256 KB. so maybe it needs to be filled.

Maybe you should test first some of the Konami mapper games that are known working.

I've an Oyanami PCB and a Casio MX10 but I need to find the TTL chip, I would like to see it by myself.

nanochess avatar Oct 21 '25 05:10 nanochess

The Oyanami PCB is 128K x 4; you can flash four 128K images back to back and use the switch to change between the four 128K images (0,0, 0,1, 1,0, and 1,1). If I flash the visrealm firmware 128K image to the active 128K bank (I forget the switch position), I get a blank screen. Else, I get dumped into BASIC as expected.

hexbus avatar Oct 22 '25 17:10 hexbus