MS3 + MV2H @ 16Mhz = cross hatch

Hi fellas,

Some time ago, i've modifed my MVS MV-2H with a 16mhz crystal plus a switch to use this new speed only in the MS series. When i has made the mod i've tested only with MS1 and MS2 games. This weekend i've started an playing marathon with the MS series, but when i will try MS3, always got cross hatch. So opened the cart, clean and tryed again, nothing. So i put other MS game on slot 1 and the MS3 on slot 2...turned on and go in to the Universebios menu, tryed calculate the CRC of MS3, all NG.

Tryed the game in slot 1 and slot 2, nothing.

So, turned the switch to 12Mhz and turn ON, BINGO the game works fine.

Someone already saw this ?

Kind regards
Macck

Short Answer: Not all games are compatible with a 16Mhz clock speed.

Long Answer: The PCM on the PROG board used for bank switching, multiplexing, etc. uses the system clock and is not capable of running at 16Mhz.

Yes, i know that a lot of games wont works properly, but i've never noticed that a MS series game don't works/ bootup.

Always i heard that all MS game series runs fine.

[]'Macck

Metal Slug 3 is encrypted, I suspect that's your problem - the chip doesn't respond quick enough. You could find a bootleg works better at 16Mhz.

GadgetUK said:

Metal Slug 3 is encrypted, I suspect that's your problem - the chip doesn't respond quick enough. You could find a bootleg works better at 16Mhz.

Click to expand...

Good point, i think you can be right.

[]'Macck

GadgetUK said:

Metal Slug 3 is encrypted, I suspect that's your problem - the chip doesn't respond quick enough. You could find a bootleg works better at 16Mhz.

Click to expand...

Not necessarily a boot. There are some originals that use a standard PROGBK1 with unencrypted roms, but they seem to be rare. I think I have one of them, I'll look for it.

Regards.