8 Jan
2007
8 Jan
'07
9:48 p.m.
On 8 Jan 2007 at 13:12, Chris M wrote:
Right, but again I doubt these things would even
respond to INT 10h and 27h, much less a lower level of
access. Even my piddly little hacked up utilities from
by gone days would be useless with such a unit.
Correct me if I'm wrong though.
Hmmm, I don't know of a single floppy drive that responds to the
video interrupt (10H) or Terminate-and-Stay-Resident (27H). I assume
you mean INT 13H (BIOS Read/Write) and INT 25H and 26H (MS-DOS
read/write logical sector).
We did a special project for the backpack that gave one low level
access to the drive under both DOS and Win9x, but never received much
of a demand for it, except for a few custmers needing to read NEC
9801 CP/M formats on their laptops.
As far as USB drives--forget low-level access. These things have
firmware that understands 512x9x2x80, 512x18x2x80 and 1024x8x77
"conventional" formats, but nothing else. Conversation with the
drive resembles ATAPI or SCSI protocols; i.e. relative sector (LBA)
addressing. While there are USB MS-DOS drivers, don't expect
anything like INT 13H access.
Some very old USB drives had a separate controller board that talked
to a conventional drive; depending on the firmware, they might be
able to talk to 5.25" 1.2MB drives, but don't hold your breath. All
later 3.5" drives have the interface integrated with the drive
electronics, so no hope there.
Cheers,
Chuck