[pups] Duh - how do you format an RX50?

Bill Gunshannon bill at cs.scranton.edu
Fri Feb 8 23:31:56 AEST 2002

On Fri, 8 Feb 2002, Jonathan Engdahl wrote:

> I can't believe I haven't figured this out yet. I bought an
> RX50, and installed it in my PDP-11/53 running 2.11BSD. It's
> nice having that empty hole in the front of the BA23 plugged,
> but I hope for even more. The drive seems alive: if I say "cp
> /dev/ra1a /dev/null", it starts groaning and ticking as if it
> were reading the floppy.
> But how do you format the floppies?
> I tried XXDP/ZRQCH0 (downloaded via VTserver), but it says the
> floppies are UNFORMATTABLE. That does that mean?

RX50's came pre-formatted from DEC.  There was never a way to
format them on PDP's or VAX as far as I knew.  I do think it is
possible to create them using PUTR and an old PC with a proper
floppy controller and a 1.2M floppy drive configured the right

My understanding is they are 80 track, 96 tpi format but spin
at the slow spead of normal 5.25 disks and not the higher speed
used by IBM HD disks.

As a curious note, I actually had (and may still have in the
attic somewhere) a real shugart 80 track 5.25 drive that would
have been the equivalent of an RX50, so it was not only DEC who
used that format.  I had them on a TRS-80 and NewDOS-80 and
DOSPlus had no problems formatting and using the drive.  This
was long before my first PDP, but I now wonder if they would
have been able to read and write (and maybe even format!) RX50's.


Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
bill at cs.scranton.edu     |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>

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