![]() ![]() I actually replaced everything under the "Boot read file code" with $FFs. What happens usually if you try to boot from side B? Did you actually change the value of that byte to make sure it isn't ignored? (e.g. Sik wrote:It's possible the firmware is using that byte (this wouldn't matter in emulation since as long as disk reads are emulated it will work, it's all done in software). I hope I wasn't too confusing in what I was trying to get across in saying. Side A is always $00 at that 7th unused byte within those last 9 unknown bytes and Side B is always $01. I compared about 7 2-sided games and 3 1-sided (Zelda I and II, Mahjong Goku, Metroid I and II, Nazoraa Land Dai 2, Knight Move, Karate Champ, SMB1 and SMB2J) to be sure. Though this one does nothing, not even affect emulation, etc. The 7th one (after the 5 $FFs on any disk) is a second disk side numery system (not as in a Side B one, but I mean since the first one is "1 Disk number (first disk is actually $00)" on the nesdev wiki). (Still I agree with you that emulation of FDS is missing GAP and CRC 'dummy' bytes.)ĮDIT: I think I made a sure discovery, here. Here is what I'm referring to, the 10 "Unknown" area on this. Right now, it seems to be completely random, which is why I think the last three bytes of that unused string is a checksum of some sort. I just thought it would be cool if there was a way to find the algorithm to it to see the logic behind it. The 3 bytes before appear to be some kind of manufacturer checksum, though it is unnecessary. But the bytes afterward, before the "Created date" is what I'm referring to, here. I think up to the boot read file code (byte $0F at 0x19 ) within that block is necessary. I was not referring to the first 16 bytes within headered ROMs. Though it is still interesting, since the "HVC" string onward to KYODAKU (meaning approved in Japanese) is official within Nintendo's original format. The actual data on the Quick Disk has more information on it than is represented in our FDS "roms". I'm not sure what, if any, useful information exists in the FDS header. MottZilla wrote:The checksums/CRCs for Disk files are absent from.
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