Gameboy Development Forum
Discussion about software development for the old-school Gameboys, ranging from the "Gray brick" to Gameboy Color
(Launched in 2008)
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#1 2011-07-26 15:42:53
- jp512
- New member
- Registered: 2011-07-26
- Posts: 1
save to non-volatile ram
HI,
I have a home made cartridge using a 32plcc 1mb flash like this one:
http://chunkout.com/images/gameboy/popu … rd_1.1.jpg
I would like to make simple game [small kb] where you enter your name on the gameboy and the game saves the name when you turn it off so it is displayed when you turn it back on.
Is this easy ? or is it impossible with out an MBC ?
The spec sheet for the flash chip says the memory can be written to at 3-5v and is non-volatile.
Is it just case of finding the correct address and writing to them ?
any leads appreciated 
[using GBDK]
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#2 2011-09-12 15:12:08
- kmeisthax
- New member
- Registered: 2011-09-08
- Posts: 2
Re: save to non-volatile ram
The way saving works on most games is that there's a static RAM mapped to 0xA000-0xBFFF (8k max); that static RAM is battery-backed. That is accomplished with a memory decoder circuit (the MBC) which only sets the chip enable line of the RAM when the address is within that particular value.
What it appears you have done is wire a flash chip directly to the cartridge bus, correct? Since you don't appear to have an MBC circuit anywhere on the board, you probably wired up the bus write request line directly to the flash chip. I'm not exactly sure how your particular flash chip accomplishes writes, though - do you have a link to the data sheet for the chip?
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