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

[Dave McGuire]

On 9/28/23 06:55, Johnny Billquist wrote:
>>    Or indeed any Unibus PDP-11.  Or any Qbus PDP-11 running directly 
>> to SMD
>> with an SMD controller that's format-compatible, which many are.
> 
> Nope. The RM05 supposedly will not work on the RH11. Too slow for the 
> disk. RH11 only supported RM02, RP04, RP05 and RP06.

   Ahh, I did not know that.  Will it actually fail to work, or just not 
work very well (overruns/retries)?  The distinction matters a lot when 
the object is to recover old data from media that nobody else can handle.

> The RM02 was a slowed down RM03 for that specific reason.

   Yes.

> As for SMD - not sure. DEC certainly used those OEM drives, but for some 
> reason the capacity was always less than the original drive, which makes 
> me wonder if DEC did something more funny as well.

   We'll check the print sets when/if someone takes on that project. 
But my admittedly decades old memory does recall that a CDC 9766 on an 
Emulex controller (possibly an SC03) is media compatible with an RM05.

   It's definitely the case that an Emulex controller (specifically) for 
the VAX-11/750, whose model number I've forgotten, connected to a CDC 
9762 is media-compatible with the RM02.  I ran such a configuration at 
work in the early 1990s and regularly moved packs between the two.

              -Dave

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