Is this an RK05? Can anyone read it? - test-drb@ccmp.vtda.org

17 Jun 2005

I have 3 working RK05 drives on my PDP-11/40 and have used them to 
successfully read and copy the data from RK05 packs that had not been 
spun up since the 1970s and early 1980s, but I guess I'm on the wrong 
side of the ocean.

Good luck with recovering the data.  I know what it's like to finally recover
data from a pack that has been lying dormant for nearly 30 years.  It's 
quite an exciting feeling, especially if it's stuff that you or your associates
developed and you had once written it off as "lost forever".

Ashley

-----Original Message-----
From: Johnny Billquist <bqt at Update.UU.SE>
Sent: Jun 17, 2005 8:00 AM
To: cctalk at classiccmp.org, gtoal at gtoal.com
Subject: Re: Is this an RK05?  Can anyone read it?

On Fri, 17 Jun 2005 Graham Toal <gtoal at gtoal.com> wrote:

Hi.

...
  There was once a student project to write a
multi-tasking operating
 system for the PDP11.  Written at Groeningen University in the
 Netherlands under the supervision of professor Harry Whitfield,
 this O/S had more than a passing resemblance to the classic
 mainframe O/S, EMAS, from Edinburgh.

 The O/S was thought to be lost apart from small excerpts that were
 documented in the project report (online at:
 http://history.dcs.ed.ac.uk/archive/scans/guts/ )

 but a disk pack has turned up which has a fair chance of containing
 a working binary and sources.

 We think this is an RK05 pack for a PDP11:

             http://www.gtoal.com/images/rk05.JPG

 Can anyone confirm that? 
It's definitely an RK05. If it is for a PDP-11 is another issue.
RK05 packs are hard sectored. If you look at the bottom, you'll find a
metal edge with grooves in it. The grooves marks sectors. A PDP-11 RK05
will have 13 grooves. If it's for a PDP-8, it will have 17. I've also seen
packs with 32 (or if it was 33) grooves. Don't know what system that is
for.

The grooves are evenly spaced, except for one, which is two grooves rather
close together, which marks the start of a revolution.

...
  And is there anyone in the UK who could read the
drive?  It may be
 in a format that is backwards compatible with one of the DEC O/Ses,
 or it may be unreadable at the FS level, just readable at the
 block level.  (Which shouldn't be an insurmountable problem, given
 the scan of the documentation; also a disk image should pop right
 in to one of Bob Supnik's emulators.)

 If someone trustworthy in the UK would like to have a go at
 reading this drive, the keeper of the disk pack (in Edinburgh,
 Scotland) will mail it to you.  It would have to be someone who
 I recognise from the list or who would be vouched for by a
 list regular.  As you can imagine we're a little squirrely
 about sending the only copy to a stranger, especially in view
 of an unfortunate experience we had last year.

 This drive probably has not been spun up since 1978 or 79.

 If anyone would like to help, please email me at gtoal at gtoal.com 
Well, I'm not in England, and you probably don't know me. I probably do
have the ability to read the pack, but it would require some work on my
part. The PDP-11 I have with an RK11 controller is located 80 km from me,
and it don't have any RK05 drives attached today. I have PDP-8 systems at
home, which have RK05 drives. So it would mean getting an RK05 into a car,
drive to where the PDP-11 is, hook things up, and then run.

And I'm in Sweden.

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt at update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol