Re: Disassembling an FST...(what about FAT?)

[dempson@actrix.gen.nz (David Empson)]

Supertimer <supertimer@aol.com> wrote:

> mattack@area.com (Matt Ackeret) wrote:
> 
> >BTW -- how are any of the portable filesystems?  like the CD ones, or the
> >DVD filesystem.
> 
> How about FAT (which MS-DOS uses)?
> 
> I've been thinking about this and it seems that the MS-DOS FST is faster
> than the HFS one.  Not only that, but the HFS one uses the block space
> for the Apple II boot function, so HFS disks can't be booted without
> modifying the SCSI card or Smartport ROMs.
> 
> What about FAT?  If the MS-DOS FST was read/write and GS/OS
> was installed on an MS-DOS volume, could GS/OS boot from it?

Not if the disk was also able to boot a PC.  The boot code for the IIgs
and PC would need to be in exactly the same place.

The critical information about the drive geometry is at the end of the
boot block, so it shouldn't cause any problems (unlike HFS, which has
similar information at the start of block 0).

FAT is also not a good fit for the GS/OS virtual file system.  HFS is
much closer.

For starters, FAT has no concept of forks.  The Mac has to use an ugly
hack (a hidden subdirectory containing the resource forks) to get around
this.  Most of the file attribute options are missing, and there is no
way to store a file type without some kind of auxiliary file (as with
the Mac using FAT).

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand