Back to: Nintendo - Game Boy Advance

Possible underdump?
Category: ROM data
Reference: 3003
Closed (accepted) by: omonim2007.
Prominos » 2023-06-05 19:20:20

I couldn't help but notice that the ROM chip is a Sharp LHMY5MTI, I can't find the size of this MROM chip anywhere on the web but this aging cartridge dump seem to be 16Mbits

If you check zand dump of Mario Kart super circuit it seems to have the same chip Sharp LHMY5MTH, only the last character is different but afaict the last characters always change on Sharp chips.

The size of Mario Kart - Super Circuit is 32Mbits so I am wondering if the aging cartridge could be half dumped?
Smelly-Ghost » 2023-10-22 10:16:43

Hey! Thanks for the question and sorry for the late response, I'm the owner of the cart and original dumper. I've gone ahead and dumped the cart again with 32Mbits and the output file is only filled with 0xFFs past the 16Mbits file size I originally dumped. Perhaps though that it is a full 32Mbits ROM chip and the ROM data itself only fills about half? I think I originally dumped it as big as I could and then checked existing revisions to see what they dumped and they all were 16Mbits (2MiB) and since it was just empty data past that point anyways I submitted it as the size it is. If anyone has any thoughts on what's best practice in this case I can submit the data for 32Mbits as well.
Psychofox11 » 2023-10-22 15:33:09

My understanding is that we're always about full chips especially with real original releases. I think this would kinda fall along the same lines as a retail cart. The only exception I know is some newer games that use larger chips because smaller are hard to find. For example, if a game is 3.5MB then padding to fill a 32MB chip, and is a new aftermarket, we might assume what the original chip would have been and use the next power of 2, and make it 4MB. For original releases, I think recording the full chip is important. Many will do a full-chip dump to check and see if it matches a hash here etc.
Smelly-Ghost » 2023-10-23 07:03:35

Yeah agreed. I worked with LesserKuma and verified that actually all three Aging carts that I own are currently underdumped in the database. I've done proper full 4MiB dumps and submitted those. Thanks for pointing out the issue Psychofox11. I don't have v7.1 to verify though.