23 Feb
1998
23 Feb
'98
5:30 a.m.
William Donzelli quoted me as having written:
OK. To be strictly accurate, all 3090 models of which I am aware are
water cooled machines. I was a student when I worked at IBM - a year
before going to university, and two summer vacations - after which I
somewhat lost touch with them. My last job with IBM was in 1988, and
not at the marketing location where I had worked before, but in a
factory building cash dispensers. My last real knowledge of IBM was
Ouch! But you may get away with providing a fake "ac good" signal,
rather than ac for it to monitor.
All 3090
models are indeed water machines. The 3090 was IBM's large
mainframe of the late 1980s.
Are you sure that there were not a few air cooled models towards the end?
I have an air-TCM from, I believe, a late 3090. I paid two bucks for it.
In hindsight, I should have purchased all of them in the chassis (25 or
16, I do not remember offhand. from 1987, then.
involved!) to
replace the strange 400Hz thingies. And a little circuit
to provide a 400Hz heartbeat if the machine uses this at all...
This is probably the best solution.
It probably does monitor the 400 Hz, and machine check if it goes away.
Remember, these machine monitor EVERYTHING (like the earthquake sensor in
some of them - give them a good kick and they will report a seismic
check). The "Mill" was chopped up into smaller rooms
- our room just happens not
to have mice power, but the one next door does.
Strange - I shouldn't have thought it took much to power a mouse :-)
Still, this means you shouldn't have much difficulty with the upgrade.
Philip.