[Simh] EXT :Re: PDP-10 simulation: DEUNA support help needed

[Johnny Billquist]

On 2015-05-01 02:41, Johnny Billquist wrote:
> On 2015-05-01 02:03, Timothe Litt wrote:
>> On 30-Apr-15 19:13, Cory Smelosky wrote:
>>> On Thu, 30 Apr 2015, Timothe Litt wrote:
>>>
>>>> In DEC, volume shadowing was first built into the HSC50 (a CI-based
>>>> disk/tape controller), released in the early 80s.  Drives were the 14"
>>>> RA81 and follow-ons.  The early design work was in the late 70s.  The
>>>> TOPS20 announcement of the CI, CFS and clusters predated the VMS
>>>> announcement, to the great annoyance of the VMS crew, which had it
>>>> running internally but wasn't permitted to announce it.  TOPS20 didn't
>>>> support volume shadowing.  Neither did TOPS10, though it did support CI
>>>> disks and tapes (but not clusters) later.  The CI/MSCP protocol layers
>>>> used common code in both OSs, similar to what was done with DECnet.
>>>> Host-based volume shadowing came considerably later.
>>>>
>>>
>>> So...were MSCP drives connected to the KL/KS over CI to an HSC50?  I
>>> saw MSCP drivers but couldn't figure out how they were attached. ;)
>>>
>> KL only (KLIPA = KL -> CI adapter).  No CI adapter for the KS.
>
> Of course, the curious mind, especially in the light of where this
> thread started, then wonders if not the UDA-50 would be possible to use
> on a KS...?
>
> Hmm, that might fail on that the UDA-50 might not have been able to deal
> with 576 byte sectors... I seem to remember you needed some specific
> versions of CRONIC for the UDA-50 to use 576 byte block disks...?

Dammit. I need to fix my fingers. That last "UDA-50" should have read 
"HSC-50".

	Johnny