[Info-vax] Assistance needed!! working RM05 drive and VAX needed for proje

[Dave McGuire]

On 9/29/23 03:25, gah4 wrote:
>> LSSM is not going to be doing any flux-transition imaging on a 9766.
>> If that's what the OP wants, he's not going to have an easy time finding
>> it. We could certainly do it with a lot of time and money, but there
>> aren't a lot of 9766 packs out there anymore, so it really wouldn't be
>> worth the investment in time and effort.
>   
> (snip)
> 
> Sorry, that was my suggestion.  Not knowing all the details ...
> how hard it is to find the appropriate host, controller, drive, and whatever
> else might be needed.

   Oh ok, no worries.

> It is convenient in that it removes some of the possible problems,
> but as you note, creates others.
> 
> It seems that the 9766 is SMD, and someone might have done
> flux-transition imaging on SMD disks before. (Or maybe not.)

   Yes, Chris Fenton did so with a 9762 to recover Cray's COS OS.  It's 
possible.  But frankly if we're going to get the drive running to that 
degree anyway, we may as well just connect it to a controller.

> Past that, I don't know that high or low level formatting is the
> same for all systems using such drives.

   It's not, but some of the third-party controllers were specifically 
designed to be format-compatible with generic (i.e. non-DEC-repackaged) 
drives, i.e. an RM02 is a repackaged CDC 9762 SMD drive with a MASSBUS 
interface in the bottom, but an Emulex SC03 controller connected to a 
CDC 9762's SMD interface will read and write DEC RM02-interchangeable 
disk packs.  I've done this myself with a different (also Emulex) 
controller, at work in the early 1990s on a VAX-11/750.

                -Dave

-- 
Dave McGuire, President/Curator
Large Scale Systems Museum
New Kensington, PA