I have sound problems too with my MegaFlashSCC+ and NMS8050:
- Insert Flash + original Salamander -> No sound at all.
- Run my own project on Flash (with and without /P) -> Only SCC sound. The PSG just 'clicks'. (I use "opfx cc.rom /p" )
- Run my game with odo + Flash -> No PSG only the 'clicks'
Without flash -> PSG works on all my original games (including my own project).
I understand it might be NMS8050 harware related. But why doesn't it happen with original Konami's?
Hope to test it soon on my other MSX-es......
Update:
I changed the PSG ports in my project to the external ones (starting at 0x10). I now hear PSG sound.
Is there info on how the PSG patching works? Does it only patch direct "out (0xA0)" (etc) and not the " out (c)"?
Yeah, patchers are unable to know what c in out (c) is, unless they insert a jump and check c (complex solution). They're also unable to know whether the piece to be patched is code or data. I don't know if there's any way to make the program tell you what it patched, but you could of course just dump the flashed+patched ROM and check for differences yourself.
What I'd do if I'd want my game to work properly on that flash cart: autodetect the cart, write the base port ($a0 or $10) to RAM, and use that value with out (c).
Same problem here on my 8250. The PSG almost cant be heared when the Megaflashrom is inserted. Even in basic (e.g. play "abcde" ). Weird thing is: with an FM-PAK or Music module inserted I can hear the PSG although the volume is slightly less when compared to no cartridge inserted at all.
I've had someone else look at this problem as well. In my 8250 and his 8250, the PSG is almost inaudible when the MegaFlashRom is inserted. Original Konami SCC and also a Manbow 2 cart are fine, and the PSG can be heard. When the MegaFLashRom is inserted in another type of MSX, no problem and the PSG is audible. So it seems to be a probleem in both the MegaFlashRom and the Philips 8250.
i also have the same problem before, but i fix it like using 2 transistors (value 2,3 Ohm) from the pin 49 leg of the cart to the pcb, with good results!!
see link : http://www.mijnalbum.nl/Foto-NPHJDBPA.jpg : notice the red circle !!!._,
But doesn't that impact a lot more then just the inaudible PSG when using the MegaFlashRom? On my machine there are no other sound mixing errors (e.g. PSG sounds good and a PSG/FM-PAC or PSG/SCC combo alsol sound fine, except for the MegaFlashrom)
no it wont, you have a better sound mixing also..
Cool. I got a hint yesterday that you might have an answer for this problem Now lets see if I dare to do this myself.
goodluck Creepy, you won't regret it when you do, i've modded my nms8255 more ways so it aint standard any longer