The problem is the vast number of DFS solutions available BITD. Acorn, Solidisk, Watford, Viglen, Opus,... And some of those had E00 verisons using SWRam.
Then add in modern variations; MMFS, MMFS2, MMC, UPURSFS, RAMFS in all their variations.
And the greater likelyhood that a modern device might have NFS so even the standard reserve "E00-1100" might not be true.
Anything you do will be compromise.
Since you need DFS to work I would not touch filesystem workspace in zero page (so B0-CF); you can't be sure one ROM or another might hit a location that Acorn didn't use.
I would be careful of NMI at &D00; at the very least have &D00==RTI just in case.
And throw caution to wind; skip E00-1100 but steal 1100 onwards (assuming you're not doing OPENIN/OUT/UP but just *LOADing files into memory)
Then add in modern variations; MMFS, MMFS2, MMC, UPURSFS, RAMFS in all their variations.
And the greater likelyhood that a modern device might have NFS so even the standard reserve "E00-1100" might not be true.
Anything you do will be compromise.
Since you need DFS to work I would not touch filesystem workspace in zero page (so B0-CF); you can't be sure one ROM or another might hit a location that Acorn didn't use.
I would be careful of NMI at &D00; at the very least have &D00==RTI just in case.
And throw caution to wind; skip E00-1100 but steal 1100 onwards (assuming you're not doing OPENIN/OUT/UP but just *LOADing files into memory)
Statistics: Posted by sweh — Tue Feb 25, 2025 2:59 am