21 Jun
2015
21 Jun
'15
9:32 a.m.
On Sat, Jun 20, 2015 at 10:58 AM, tony duell <ard at p850ug1.demon.co.uk> wrote:
> I am looking for any information on a National
Semiconductor RAM board that I think goes in
> a VAX 11/730.
Pressing the
button turns off the yellow LED and completely disables the board. Quite why you'd
want to do this I do
not know...
The reason you'd want a button to disable the board is when running
diagnostics, you can "remove all the non-DEC memory" without
physically removing it. Of course it still could be the source of a
problem, but at least operational memory boards can be "deleted" so
they don't grossly affect the diagnostic code.
It's a "feature" to allow customers to buy less-expensive RAM and
still have a way to pass diagnostics without fingerpointing from DEC
about that "other" board in there.
-ethan