local demolition of SAGE building
mloewen at cpumagic.scol.pa.us
Tue Jul 19 15:23:21 CDT 2005
On Tue, 19 Jul 2005, Teo Zenios wrote:
> How many vacuum tubes would need to be replaced yearly, and how would a few
> breaking affect the functioning of that equipment in real time?
I don't have the figures for annual tube replacement, but it was a
continuous process. As I mentioned in my last note, the marginal checking
system allowed us to pull suspected flaky or about-to-fail tubes before
they failed on duty.
Various SAGE histories have reported "technicians running up and down
the aisles pushing shopping carts full of tubes". I don't know about
other air divisions, but I never saw it.
Towards the end of the system's life, the remaining SAGE systems had to
make due with tubes scrounged from previously deactivated systems.
According to others who worked on the system, sometimes the replacements
were worse than the ones currently in use.
The SAGE system actually had two computerss: one running the air
defense program and the other usually on standby. When the standby system
wasn't undergoing preventive maintenance (PM), it would be receiving
updates from the active system in case it needed to take over. If the
standby system sensed that the active computer was no longer functioning
correctly, it would automatically switch over and start cycling the air
defense program. If something happened that the standby didn't
automatically switch in case of a failure, we'd have to do a manual
switchover. Depending on the circumstances, this procedure could take up
to 3 minutes, which is all the down time we were allowed before having to
report a "noplex" condition to NORAD.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/
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