What features an "ideal" MSX combo-cartridge should have?

By sdsnatcher73

Prophet (3852)

02-04-2022, 10:50

I don't know how GM2 S-RAM detection works, does it need the ROM? But yeah would be a nice option.

By gdx

Enlighted (6120)

02-04-2022, 11:07

This is explained here:
https://www.msx.org/wiki/ROM_mappers#Game_Master_2_.28Konami.29

And a cartridge Game Master 2 compatible has already been made.
https://www.msx.org/wiki/ESE_RC755

By Pokun

Expert (68)

02-04-2022, 16:34

Don't forget other SRAM mapping used in some ROM-cartridges like Hydlide II.

By sdsnatcher73

Prophet (3852)

02-04-2022, 17:37

gdx wrote:

This is explained here:
https://www.msx.org/wiki/ROM_mappers#Game_Master_2_.28Konami.29

And a cartridge Game Master 2 compatible has already been made.
https://www.msx.org/wiki/ESE_RC755

I don’t see any explanation how games detect GM2 S-RAM. Probably the ROM is needed for detection. Using FRAM is a nice idea, that would be a nice to have.

By sdsnatcher73

Prophet (3852)

02-04-2022, 17:40

Pokun wrote:

Don't forget other SRAM mapping used in some ROM-cartridges like Hydlide II.

Yeah that would be a nice addition, especially if there was support so that SofaRun would be able to configure and use it.

By sdsnatcher73

Prophet (3852)

02-04-2022, 17:49

Come to think of it, on the fly config changes would be a great feature, won’t work for everything obviously but let’s say you wanted to swap the FM with a second SCC for games that require it that would be great to do without a reboot (like hot swapping real carts but much more safe and controlled )

By Parn

Paladin (833)

02-04-2022, 18:29

For me, GR8NET is the closest to a perfect combo cartridge. But some very desirable specs are:

SD card reader (no CF nonsense)
The full sound combo: MSX-MUSIC, MSX-AUDIO (with BIOS), SCC+, extra PSG
Dedicated stereo audio out
Stereo sound mixer with panning
8MB memory for cartridge emulation (or more)
At least 2MB memory mapper expansion
Updateable from the MSX, no need for external tools or opening the cartridge
Online configuration where possible (like OCM)

Some cool extras:

Dual SD card reader
Other sound chips, like YM2151 and SN76489
Wi-Fi

I personally don't think it makes much sense adding in V9990 and OPL4. I think it would make the cartridge prohibitively expensive. All of the above can be implemented in a satisfactory way with FPGA and some easy to find and inexpensive support chips. I'm aware many of the above require a slot for themselves so it's probably impossible to configure all at the same time.

By sdsnatcher73

Prophet (3852)

02-04-2022, 18:51

OPL4 can be added in the same FPGA (if the FPGA has enough capacity). V9990 does not have an FPGA implementation (yet), maybe after MSX3 release it does (but I agree it makes less sense and would complicate all too much).

By Wierzbowsky

Guardian (3571)

07-04-2022, 01:52

Thanks for your feedback!

By RvS

Expert (94)

07-04-2022, 08:14

Hi, in my opinion, the carnivore2 comes pretty close already.
But if I could add a few features:
-sd card slot iso. CF
-usb port for file transfer/live debugging/firmware updates from pc