On May 8, 11:09, Ethan Dicks wrote:
> --- "Fred Cisin (XenoSoft)" <cisin_at_xenosoft.com> wrote:
> > On Wed, 7 May 2003, Nick Garnett wrote:
> > > Does anyone know the whereabouts of any working 8" floppy
> > > drives?
> > Have you considered substituting 1.2M 5.25" drives?
> > Once you make the appropriate cables and jumpering, they will
usually
> > work as a drop-in replacement, with NO software changes.
>
> Serious question (not meant to merely contradict Fred), what would it
> take to do that for an RX01 or RX02? The drive mechanism itself in
> a DEC 8" drive has no electronics - it's a motor, a head loading
relay
> (the drive motors spin whenever the unit is powered on, unlike modern
> equipment), a couple of sensors and a head cable. All of the "work"
is
> done on the board above the drives.
There might be issues around matching the head's impedances etc to the
preamps and drivers on the RX01/2 electronics, and possibly even around
the step angle of the positioner, but nothing inssurmountable, I
suspect.
> Even getting past electrical issues, one trick would be how to
low-level
> format the disks.
Not too hard. An RX01 floppy is a standard format; you could do it on
any CP/M machine that exepcted 8" drives but actually had a suitable
5.25" drive, or on a PC with a suitable FDC and suitable version of DOS
(or Linux, probably), or indeed on many other systems. Once formatted
to single density (RX01) most DEC system can then "reformat" the disk
as RX02 (modified double density).
> Among other reasons for doing it is that I have an RX01 that came
from
> a client with a siezed rotation motor on one drive and a siezed head
> positioner motor (with attendant incinerated head motor driver
> transistors) on the other drive. Yes, I can repair the transistors
and
> move one good motor to the other mechanism, but it means that I have
1/2
> of a full RX01.
I had a drive motor seize on my RX02. It wasn't all that hard to free
the spindle, clean the bearings, and re-lubricate them. It's running
fine now. It's certainly worth a try.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Thu May 08 2003 - 16:15:00 BST