[Info-vax] VAX 6000 on Young Sheldon

[Rich Alderson]

Johnny Billquist <bqt at softjar.se> writes:

> On 2023-02-11 17:26, Arne Vajhøj wrote:
> > On 2/11/2023 11:18 AM, Tony Priborsky wrote:
> >> 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?
> 
> Depends on how you mean that. Tapes have CRC on the data unless I 
> remember wrong. Just like disks have. But no redundancy or ECC, so if 
> media got corrupted, you loose.

Hmm.  In 50+ years of data processing/IT/systems work, I've never heard of
tapes having (nonprogrammatic) CRC, that is, anything generated by the
hardware/firmware rather than the backup program.

> But HSCs are pretty nice. Been a while since I used one.
> 
>    Johnny

-- 
Rich Alderson					  news at alderson.users.panix.com
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