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So you can keep you games saves safe while using loader. Saves, plural? Or will other games that use RAM overwrite your save? Is RAM even present on most carts? And won't writes to RAM trigger the lockout by accident? Other games will overwrite save, yes :( I wrote "saves" bacause usually...

you MUST enable writes to the MMC3's PRG RAM to write to these registers

Actually it's not true. You can disable PRG RAM and write to $6000-$6003.
So you can keep you games saves safe while using loader.

getafixx wrote:but how does it handle PRG and CHR? If there is only 1 chip for data (the other is some kind of mapper i'd assume), how can it run both busses?

There are 128KB/256KB (depends on revision) of CHR RAM. Game loader loades all CHR data to RAM before game starts.

How does the menu select which game to play? The MMC3 only supports 512 KiB (or maybe 2 MiB), and none of the documented multicart mappers go above 4MiB ... so how does it address 32 MiB of flash? It's "COOLBOY" MMC3-based mapper. It has additional registers. You can view it in fceux sour...

Hi. I just found that there are flash memory on a cheap "coolboy" cartridges (about $3). So I can rewrite it! All you need is to unsolder /RD and /WR pins. So I can use my dumper with JTAG connector. coolboy_rewrite.png Video (russian language, sorry): https://youtu.be/5_XZyVoEzE0?t=4m46s ...

ExtraOrdinary wrote:Which model of FTDI chip are you using?

FT232RL.

I'ts not so easy to route one-sided board using only one MCU and latches Maybe I'll order board on factory later. But it's only for private usage, experiments and self-studing.

tepples wrote:In theory you should only need to use one, with the PRG and CHR sharing an address and data bus, just different enables.

I know but I decided to separate them for the first time to avoid any mistakes.

ATMEGA64. Actually two of them - one for PRG memory and one for CHR memory.

Solved. I wrote "DDRD = (1<<7) || (1<<6)" instead of "DDRD = (1<<7) | (1<<6)" so R/W pin was only pulled up to VCC.

Hi. I'm developing my own dumper for famicom cartridges. Seems like it's working fine for MMC3 games, at least I can read some data. But when I'm reading any MMC1 cartridge there are always "FFs" for any address, even $FFFC (reset vector). Maybe I'm doing it wrong? Or some initialization r...