Yah, I done that. The key is to find an MFM drive that has the
same or greater Cylnder/Head geometry: It has to have at least
the same number of cylnders, and at least the same number of
Right. Some machines seem to check if the drive actually _matches_ (as
opposed to exceeds) the required geometry. They'll attempt to select a
non-existant head and check an error is generated, and so on.
Keep in mind, though, that geometry alone does *NOT*
that this will work!! The 9133 seems to be allergic to some
One problem is that HP made a number of devices called a '9133' that had
little internal similarity. They were all hard/floppy disk units, they
all had HPIB interfaces, but that's about it. The earlier ones (9133V,
XV, etc) had separate hard and floppy disk controller boards inside, each
with their own HPIB address and used the Amigo command set. The later ones
(9133H, etc) had one controller with one HPIB address and used the SS/80
command set iIRC.
So saying that something works/doesn't work for a 9133 is somewhat
meaningless. It may work for some versions and not others.
MFM drives-- I could get most Seagate drives to work,
but not NEC's. My fave at the time was the Quantum Q540. I
'wasted' over half the drive, but I had alot of them at the time!
When you format such a drive, you will not have a capacity
greater than the original.
 Not quite true for the older 9133 V/X/XV drives. If you have
a 'V' for example, you can replace it with a bigger drive, adjust
the jumpers inside, and format for 10 or 15MB.
The 9133H has a set of 3 jumpers on the controller board labelled 'Ident
Sea'. These seem to set the controller for different geometries, but I
have no idea what all 16 possiilites actually are. Anyone?