5 Mar
2017
5 Mar
'17
11:27 a.m.
On 03/05/2017 10:41 AM, Mark J. Blair via cctalk wrote:
So, was the write enable state latched at some point in the loading
cycle on those drives? That surprises me, because I would have
expected the write enable sensor to interrupt write current as
combinatorial function on the drive, and/or pass sensor status up to
the formatter a combinatorial signal.
Yup. You loaded the tape, then bumped the "finger". As I mentioned,
this worked on 60x and 65x drives. Since the autoloaders closed the
door as part of the cycle, this probably didn't work for 66x.
This actually worked pretty well--you never ran the risk of leaving a
ring in inadvertently. The consequence of forgetting to enable write
was usually far less dire than mistakenly writing to a tape that was
supposed to be read-only.
--Chuck