Thanks for all your help! Very interesting feedback. Seems they didnt offer a lot of consistency on this topic. Using an 8 bit checksum vs. 16 bits in others, plus, the locations of such. I'm also now starting to wonder if in the patches they made to the roms they were also adjusting the checksum. One would hope so.
> I used the first byte in each white ROM game ROM which is the checksum byte to id the rom. Afaik it's not in the gamerom like the later systems.
This doesn't match up for me (the first byte is not an 8 bit checksum value of the entire image). I've always wondered what that first byte was for..
> Flash 0486 2 yellow 6. Note there are two versions of Flash available, the game rom must match the flipper roms and the diag settings are slightly rearranged between the versions. The latter uses green flipper roms
Odd that version 2 of flash is yellow, while version 1 is green. (at least by the zip name: flash_l1.zip) Perhaps they mean version 1 of the green set.
> Barracora 2510 1 blue rottendog (I think it's 1, dodgy display so might be 0 - sorry)
You are correct. it is a 1
> Sys4 games would normally have yellow roms
The only game I'm seeing with yellow ROMSs is Stellar Wars.. and I agree.. you'd think white=sys3 and yellow=sys4 but this is not the case. Color must just be strictly about flipper ROM version.
I'll think some more on how to go about this. The purpose of the new test ROM would be to calculate a checksum for each of the ROMs on a board, and then compare to well-known checksum values. A proper solution to this would eliminate the need for a second chip programmed with the PATTxxxx.bin files, while also being able to pinpoint which ROM chips/sockets were bad, all in a single test ROM.
Thanks again for your feedback