9370 is a dog! Was: Re: Re[2]: Firsts

From: William Donzelli <william_at_ans.net>
Date: Sat Feb 21 20:47:01 1998

> 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.

> I wonder. I have never seen inside the PSU of any of these machines,
> but it seems to me that the outputs are all going to be low voltage dc
> at a few hundred amps - so conventional switching power supplies could
> be contrived (tho' probably not purchased new if there are tens of kW
> 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).

> Nice. I'm surprised you don't have this already if you're in a factory.
> Here we have 240V (now officially 230V but I've not noticed any change)
> single phase up to around 20kW peak demand, 415V 3 phase (now officially
> 400V, ditto) up to a megawatt or so, 11kV 3 phase above that. Some
> factories have their own supply at 33kV or even higher.

The "Mill" was chopped up into smaller rooms - our room just happens not
to have mice power, but the one next door does.

William Donzelli
william_at_ans.net
Received on Sat Feb 21 1998 - 20:47:01 GMT