--- Philip Pemberton <philpem_at_dsl.pipex.com> wrote:
> In message <Pine.LNX.4.33.0306020545020.6552-100000_at_siconic.com>
> Vintage Computer Festival <vcf_at_siconic.com> wrote:
>
> > On Mon, 2 Jun 2003, Al Kossow wrote:
> >
> > > RM05 packs are 300mb cake platters... Quite different from 2.5mb
> RK05's
> >
> > What drive is required to read them?
> Google revealed http://www.proximity.com.au/~brian/comp/vax750.html. I'm
> guessing the disk packs belonged to a DEC VAX system of some type or
> other.
> The URL I mentioned gives specs for someone's VAX 11/750 BTW. The RM05 is
> supposedly a 250MB "Massbus" disk, if that means anything to any DEC
> experts around here...
Quite a bit.
The RM05 was the largest in a particular line of MASSBUS drives based
on CDC internals. I have not personally laid hands on an RM05, but
I have worked on the innards of a number of CDC drives and of several
DEC RM03s. The RM02 and RM03 are repackaged CDC 9762 drives. The
difference being rotation speed (the RM02 was sold with RH11 controllers,
while the faster RM03 went to VAXen and perhaps PDP-11/70s). The RM05
is a repackaged CDC 9766.
I don't have the capacity figures right here, but ISTR that a raw 9762
drive (on an SMD controller) was around 80MB, but as DEC used it in the
RM02/RM03 it was an effective 67MB. I know that the 160MB SMD Fuji drive
I have emulates two RM03s, at 67B each. There may be a similar thing
going on with the 9766 vs the RM05.
You can use an RM05 with an 11/750, but it's possible that the packs
in question were also used with a PDP-11. Knowing a little about the
source might help extraction (although sticking an RM05/9766 on a
suitably equipped VAX under UNIX and using 'dd' could get you a disk
image file).
-ethan
Received on Mon Jun 02 2003 - 10:06:00 BST