[Info-vax] VAX 6000 on Young Sheldon

[gah4]

On Sunday, February 12, 2023 at 3:52:31 PM UTC-8, Johnny Billquist wrote:

(snip)

> Correct. From a hardware point of view, those are just blocks just like 
> anything else. No difference at all. 
 
> However, the tape have blocks. You have the tape marks, blocking and 
> other stuff going on, to try to ensure your data is safe and don't get 
> corrupted. It's all down in the hardware, but that don't mean it work 
> any worse/different. 
 
The first thing OS/360 and successors do when a tape is mounted, 
is read the label (,SL), or verify that there isn't one (,NL).
Systems I knew would let you read, but not write, with (,BLP).
(That is, bypass label processing.)

The drives will read until they find either data or a tape mark, or the
tape goes off the reel.  (The foil EOT markers are only used on writing.)

No comment on how I know that.