Re: building a PDP-8 computer in your kitchen

From: "Roger Books" <books@mail.state.fl.us>

> I have news for those in power in the Navy that have this silly idea
> that you can power core memory down and back up.  If you use the front
> switch it is fine, but if you take an electrical casualty, especially
> one that kicks the emergency power on, when that pup comes back up the
> memory is going to be slicked.  It is much quicker and more reliable
> to have a PROM with they system software.
> 
> Roger (Speaking from experience, I worked on a CP-642B.)

Interesting. We have a different experience with our twin-bay AN/UYK-7Bs
on our DDGs (which are basically Block II Charlie Adams with all the
trimmings bar Mk 86 - and we've got that now too. SYS-1 of course rather
than BVP) Or at least we did back in the 80s when I was working on them.
At the CDSC (Combat Data System Centre) we had a whole heap of
mains voltage problems in the mid 80s. When the mains dropped from
the 230 standard to below about 170, the machine went pfut. Similarly
the less common times when it pushed 300. But the re-starts always
went OK, no re-loading of software, and track stores were intact and
consistent.
Of course loading software from tape - and patches from paper-tape - is
something that should have been stopped long ago. Ditto the process of
laboriously entering the boot sequence on the front panel. PROM is very
obviously the way to go, and if you want Static RAM, you can have that
on semiconductors easily enough.

Don't get me started on the DEAC. Or the ICKCMX. And especially not
the EW keyset.