As part of my ongoing experiments I'd like to build a SLROM (MMC1 based) ram cart. I know I can only access 256KB of data using the ususally MMC1 hardware, but I thought it would be nice to put down a 1MB or even 2MB rams in place of the PRG and CHR ROMS. To my surprise, I was not able to find SRAM's in those sizes. Just wanted to check if anyone else has seen them, or if I'm just going crazy. I'd hate to have to wire in 4 512KB SRAM's, which were the largest I could find.
All the larger SRAMs that I've seen available are non-volatile types. So a little more expensive.
Could try the BQ4016 maybe, digikey lists those for $32 each.
I just now stumbled across this item too, it's a little cheaper and sounds better than the last one I mentioned.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3866426431
That NV SRAM actually looks pretty good. But isn't it a low power CMOS device? I think plugging that into a 5V TTL NES might fry it. Am I correct on this?
EDIT: I didn't read the datasheet properly, looks like this will work with the NES.