A/UX 2.0.1: Problem Recognizing 800K Drives with Macintosh IIfx


I am using A/UX on a Macintosh II that has been upgraded to a Macintosh
IIfx.

A/UX seems to think my 800K floppy drive is a 400K drive and that it is
bad. In fact, we can format floppies to 800K and otherwise use the drive.
But the A/UX Finder and DOSMounter certainly believe that the drive is 400K
and will only format it or use it as 400K.

An Apple Macintosh IIfx with an FDHD and an 800K drive, booting under A/UX
release 2.0.1 version SVR2 has the following symptoms:

* The 800K floppy drive is only recognized as a 400K drive.

* Part of the message from the A/UX kernel during boot reads "FD:floppy
driver ver. 1.9; iop swim, D1 is 400K (1 head), D0 is an FDHD drive."
"FD: D1 400K drive unusable."

* If the unit is not booting under A/UX, the 800K drive operates as
expected.


It is a floppy driver incompatibility in A/UX 2.0.1 with a Macintosh IIfx.
On a Macintosh IIfx, the driver incorrectly identifies the drive as a 400K
drive, and claims it's unusable because 400K drive hardware isn't supported
on the Macintosh II series systems.  If you insert a blank floppy, however,
you can format it, but only as 400K single-sided floppy.  The drive is
still usable as a 400K drive.

You can still read and write existing 800K floppies, even though the drive
says you can't.

This problem has been fixed with A/UX 3.0 and above.
Published Date: Feb 18, 2012