Writing to blockbuster game factory cartridge

[billybob884]

I've recently added a blue (32Mb) blockbuster game factory cartridge to my collection, but it's blank (presumably due to a dead battery, will verify when it arrives). Out of curiosity, if one were to replace the battery, has anyone figured out how to write to them? Or to the new leaf flash carts?

[axel]

I've recently added a blue (32Mb) blockbuster game factory cartridge to my collection, but it's blank (presumably due to a dead battery, will verify when it arrives). Out of curiosity, if one were to replace the battery, has anyone figured out how to write to them? Or to the new leaf flash carts?

I thought the 32MB carts were the New Leaf carts? When you open it up what kind of EPROMs does it have?
It will be cool if you can get it to work, it's like having a vintage flash cart from 1994.

[billybob884]

My understanding is the difference between the green and blue carts was the memory capacity; the green were 16Mb (2MB), and the blue were 32Mb (4MB). The New Leaf carts I think were a prototype/predecessor to the Blockbuster green/blue's, but I can't really find much info on them, nor their storage capacity.

There are pics of the circuit boards here:
https://www.videogamesage.com/forums...comment-269102

You can see the green has 2x 8Mb (Intel E28F008SA-120) flash chips for a total of 16Mb (2MB), and the blue had 4x 8Mb flash chips for a total of 32Mb (4MB) the maximum game ROM size (excluding games that use bank-switching techniques). That thread also has a low-res pic of one side of the New Leaf circuit board, which looks like it has the same Intel chips, but who knows how many total.

I know flash memory was still relatively new/expensive, so I guess this was done to help cut hardware investment costs for stores. What I don't understand, though, is if the carts used flash memory, why did they need battery backup at all? (and thus why do the carts lose their games over time?) I thought the point of flash memory was that it's non-volatile, so it holds its memory even after losing power.

There's also has a KM62256BLS-10L, which google tells me is a static/dynamic/video RAM chip (maybe that's what the battery was for?), and then there are two sticker-covered chips, U1 & U2, which I presume are EEPROMs with programs that control the writing process. That's about as far as I can go with my skillset, unfortunately. I suspect what would need to be done is to desolder and dump the contents of these chips and the programs analyzed to figure out how to interact with them.


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Edit: Looking at the circuit board a little closer, I suspect this is actually a 3-layer PCB. At first glance the only thing that battery appears to power is the KM62256BLS-10L RAM chip (via D3, with C2 for decoupling), but there don't appear to be any connections except for pin #20 (chip select), nor any connections to the U1/U2 chips. The battery also seems like it goes to D4, which doesn't have anything on the other end, so maybe that's also routed through the hidden plane?

https://imgur.com/a/fPbWQSb

I've no idea what could be on the RAM chip though. Can't really tell what's going on beyond that.

Funny side note, I also have no idea why some of the silkscreen text is mirrored (the date/revision/country of manufacturer), but the rest is fine (part numbers/labels).