FCEUX MMC5 WRAM Support

Discuss emulation of the Nintendo Entertainment System and Famicom.

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SoleGooseProductions
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Joined: Mon Nov 11, 2013 2:23 pm

FCEUX MMC5 WRAM Support

Post by SoleGooseProductions » Tue May 14, 2019 11:36 am

Looking over the wiki I saw that the MMC5 can support up to 128KB PRG RAM, but it seemed uncertain since it was not used in a licensed game. When I checked the change log I saw that 64KB support was added back in '08, so I am guessing 128KB support was not, but I figured that I would check with all of you. Thanks for any help!

lidnariq
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Location: Seattle

Re: FCEUX MMC5 WRAM Support

Post by lidnariq » Tue May 14, 2019 11:38 am

Correct. It's only in the past couple months that Ben Boldt discovered support for one 128 KiB RAM instead of two 32 KiB RAMs.

Due to MMC5's complexity and scarcity, I'd recommend something else, such as FME-7 with multiple banks of PRG RAM.

SoleGooseProductions
Posts: 29
Joined: Mon Nov 11, 2013 2:23 pm

Re: FCEUX MMC5 WRAM Support

Post by SoleGooseProductions » Tue May 14, 2019 11:41 am

That was the other option, but I couldn't find much about FME-7 support. Do you know the sizes of PRG Rom and RAM FCEUX supports?

lidnariq
Posts: 8785
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: FCEUX MMC5 WRAM Support

Post by lidnariq » Tue May 14, 2019 11:45 am

SoleGooseProductions wrote:That was the other option, but I couldn't find much about FME-7 support. Do you know the sizes of PRG Rom and RAM FCEUX supports?
FCEUX source wrote:setprg8r(0x10, 0x6000, preg[3] & 0x3F);
6 bits of 8KiB banks, or 512 KiB of RAM, should be supported.

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