As far as the
disk drive goes, if it is a proprietary hard drive in there,
that is a bummer.
They are conventional drives. The 360 or 380 are nice machines that will also run HP/UX
As far as I am aware the HP9153B is the same as an HP9154B
with a floppy drive fitted. The 9154B uses an HP drive known as
a 'Nighthawk' which does not have a normal interface. I've just
looked at the schematics...
-tony