Flash/SD cartridge for SX-2 FPGA?

Expert (90)

30-01-2023, 14:57

I am thinking some games may load better from an Flash/SD multicart in a cart slot than from an SD card slot trying to emulate a cart even on an FPGA which can emulate a number of the RAM expansion carts available. Also, some may have additional sound capabilities. Would there be a Multi-cart flash cart that could improve game experiences and loading on the SM-X and SX-2 OCM FPGA MSX machines?

Thanks.

Entrar ou registrar-se para comentar

Por ducasp

Paladin (680)

30-01-2023, 15:50

Swami wrote:

Thanks.

I think the only mapper the ocm devices do not emulate is the r-type one, as far sound goes, it has scc, fm and 3.9.1 has second psg as well... Don't think any cartridge will improve that support, if you have issues with sofarun try forcing the mapper type to the one from the rom, or, use mglocm. I really don't think this is an investment that is worth it

Por Swami

Expert (90)

30-01-2023, 16:18

Okay. Sometimes cartridge emulation itself is better through the cartridge slot for things like Bankswitching, ARM, sound chips, etc. than trying to emulate them through an SD card slot. That may not be the issue with the OCM though. For instance, there have been issues with DICED on SM-X, SX-2, etc. with both sofarun and mglOCM, but it sounds like most people with real machines and flash carts are able to play it unless they are all using emulation.

Obviously, just about anything could be fixed with changes to the firmware, but sometimes there are more expedient ways.

Por ducasp

Paladin (680)

30-01-2023, 20:49

Seems DICED is one of the oddbals like R-Type, so that is the second game I'm not able to run on an OCM device.

I've tried quite a few tricks, even padding the rom to align to more common sizes like 384KB or 512KB, no luck...

I've tried also quite a few settings that might alleviate some issues but no luck... I don't think this game is not running because it needs a mapper or sound chip not supported by OCM 3.9.1 (in fact, it should be quite simple to support it since it is Konami 8KB and no special hardware requirements, only the odd size but that should not be an issue too)

That could be due to:

A game issue with something that loads before it (slot 0 roms/sub-roms/etc)
A game issue with some (just guessing) mirror of registers to switch Konami 8KB that is not implemented on OCM
A game issue with something else (CPU/VDP most likely, perhaps memory layout, but that one I think it is not as I've tried on several setups on OpenMSX including one that uses ram similar to OCM and game ran ok) that is not emulated as it should by OCM

Except for case 2, all other cases won't get any better if you get a flash cart... OCM emulation of SCC / ASCII 8 / ASCII 16 / Konami 8KB mappers is pretty much like a flash cart, except it is not flash, but RAM, but as far as I remember, after being stored, for the game it looks like flash and is not writable... So there is a good chance you get a flash cart and still get the issue. I would try to talk to MI-CHI (developer of the game) and KdL / Hara (the guys that do most of the development for OCM firmware / fixes / improvements) about this and check their oppinion why the game is not running and if it is fixable, for MSX OCM has a quite good flash emulation/simulation in general, so having an additional flash cart would really not worth the money, but if you are looking for one multi cart with plenty of options and that perhaps is useful if you decide to get a MSX computer that is not FPGA based, I would recommend Carnivore