[Info-vax] VAX 6000 on Young Sheldon

[Arne Vajhøj]

On 2/11/2023 11:18 AM, Tony Priborsky wrote:
> On Saturday, February 11, 2023 at 8:14:16 AM UTC-8, Arne Vajhøj
> wrote:
>> On 2/11/2023 11:08 AM, Tony Priborsky wrote:
>>> On Wednesday, February 8, 2023 at 1:27:34 PM UTC-8, Bob Eager
>>> wrote:
>>>> On Wed, 08 Feb 2023 19:19:30 +0000, Scott Dorsey wrote:
>>>> 
>>>>> IBM guys would not have. My boss would have said that if it
>>>>> can't back up the DASDs with the CPU halted than it wasn't a
>>>>> real mainframe.
>>>> I know it was probably later on, but couldn't you do that with
>>>> MSCP disks?
>>> 
>>> Yes, the HSC50 had a direct disk-to-tape backup utility that
>>> didn't require the CPU. Consistency was your problem so it was
>>> mostly used off line. The system operated a TU78 tape drive at
>>> absolute max speed. Forward write speed was almost rewind speed.
>>> You could always tell when it was running by the sound of the
>>> vacuum columns.
>> Did it generate a backup in VMS Backup format or did it just dump
>> physical disk blocks to tape blocks?
> 
> I'm pretty sure it didn't write a native VMS backup saveset -
> remember the CPU on the HSC was a PDP-11.   Logically the backup was
> the equivalent of VMS "BACKUP/PHYSICAL".  I seem to recall that at
> some point the VMS backup could restore (read) a HSC backup.

So no CRC and no redundancy groups?

Arne