I think the original question was how to tell if it's 64mb or 256mb, only way I could think of if it still works with 4x1mb per group then it doesn't support 256mb. I imagine if you have one of the 256mb upgrade ROMs they probably put a sticker on noting that. It's not just the SCSI ROM that needs updating, one of the PLDs needs replacing as well. I couldn't find anyone that has the code for that so it's probably lost.
