🚀 go-pugleaf

About problems interchanging 3.5" disks between ST's and PC's:

There are two potential problem areas:

1. The ST uses a Western Digital floppy controller chip.  PC's typically use a
   different one (NEC or it's Intel equivalent?).  Apparently under at least
   some circumstances the Western Digital 1772 can produce a low level format
   that the PC controller has trouble reading.

2. MS-DOS/PC-DOS initially put disk type information in the first entries in the
   disk FAT table.  Later revs have moved that information to sector 0; but for
   compatibility reasons disk type info is normally in both sector 0 and in the
   first FAT entries.

   GEMDOS on the ST only puts the disk type info in sector 0.  Therefore is a floppy
   driver on the PC expects to get the disk type info from the first FAT entries,
   it will get confused.

About sub-directory problems: while I haven't tried this from a "strict" PC/clone,
I have from an Amiga Transformer running PC-DOS 2.10 and 3.2.  The ST had no
problems reading those sub-directories.  A possible cause is that GEMDOS expects
to see "end-of-directory" at either the end of the sectors allocated to the directory,
or with an entry that starts with a zero byte.  If that wasn't the case you
definitely could get a crash.

dgc