From: Jim Brain (brain_at_jbrain.com)
Date: 2007-12-31 19:54:02
Ruud@Baltissen.org wrote: > Hallo Jim, > > > >> Still, the closer you can keep the FS to CBM specs, I think the better. >> > > Then I take this as an shameless opportunity to promote my own LBA system > :) > > - instead of two bytes it uses four bytes to link to the next system. Four > bytes minus one bit support up to one TeraByte! > Sounds great > - it uses a BAM but without the 'free sectors/track'-byte. The BAM only > keeps record of what sectors are free or not. > Not sure of the specifics, but sounds fine to me. > - a directory record looks the same as the original one except four link > bytes except two. > Great. > - very first sector contains some system info, like the diskname, disk > size, size of a sector and the start sector of the directory > - the BAM starts at the second sector > - the directory start after the BAM > As stated before, I'd prefer to see the drive contain a std IDE boot sector (with partition info), and put this stuff at the sector noted by the partition info. On the system-info sector, I'd be happy to look at 0x83, FAT, IDEDOS, etc. to come up with a common FS-boot block if you want. > My LBA system can support 256 and 512 bytes sized sectors: if the MS bit of > the 4th byte of the link is set, then this sector is the last sector of a > file. The first byte, in case of a 512-bytes sized sector the second byte > as well, tells the system how many bytes of this sector are used. > I'm assuming you're talking bit 31 of the link, right? Hehe, that means, of course, that one cannot use a sector above 1TB :-) no worries here. The only practical way we'll get there is if someone creates a partition on a >1TB disk near the end. 1TB disks being so common and all, in PATA format... > I started with removing references to the second drive. I also want to > remove all references to the disk ID. As I cannot swap a disk, why would we > need a disk ID? Showing the directory, the first line will display: > On the disk, I think that is fine. However, I would still leave a spot on the DIRectory block for the ID and DOS-type (2A), in case someone wants to modify them. > 0 "DISKNAME " X-IDE > > 'DISKNAME' can be changed. Formatting of the disk can be done with and > without the ID option. With ID the system only accepts the characters 'ID'. > This because formatting a real disk will take quite some time. You can > compare it with the quick option for DOS format. > > When writing this, I already removed the write protection routines. But it > just occurred to me it could come in handy. Your oppinion, please! > I'm not sure I understand this. You mean for "locked" files (>PRG) and all? For my part, I don't have X-IDE HW as yet, but I'm trying to finish my LFN/FAT16-32 support in uIEC, so I at least know what one needs to do to maintain the FAT FS integrity. (Reads are easy, and I got them finished, writes are another story, of course) Jim Message was sent through the cbm-hackers mailing list
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