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

[Johnny Billquist]

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...?

	Johnny