The Cyber Era:
Ivinson Machine Room
Some pictures of the Ivinson machine room, circa 1985 or so.
Taken by Brad Thomas.
This is a crude two-part panorama of the "back room" where the
mainframes sat. (You may need to widen the window on your browser to see
it all). In the foreground left is the Versatec offline rasterizer
and plotter, and a CDC controller (card reader/punch?)
next to it. Behind those is the Cyber 840. Split by the two
photos is the wall-mounted dewpoint/temperature recorder,
and in the foreground is the condenser (chiller) for the Cyber 760.
In the very foreground you can just see two of the covered
cameras for the FR80/A film recorder. To the right of the
dewpoint recorder is the ECS chassis. On the right is
the 760 chassis.
If you open one of the outer doors ("skins")
of the 760, this is what you would see. In this case Bay 2
which is the backside of the plug-in logic cards (2.5 by 3 inches each).
The cards are conduction-cooled via freon running through the aluminum
main frame; the freon is cooled by the condenser unit mentioned in the
previous picture, which is cooled by chilled water, which was chilled
by freon from a refrigerator unit on the roof, which was cooled by air.
I *think* this bay was entirely PPs and support modules which were narrower,
had simple pads for test points, and a module consisted of two cards
sandwiched together. CP modules were wider, had coaxial test points,
and are 8 cards thick. On the far left you can just barely see some of the
channel cables. This main chassis would swing out (hinged on the left)
to expose the backplane, a truly impressive rat's nest of wire-wrapped
twisted pairs. Sorry we don't have any photos of that. Note that Cybers
used balanced ECL logic for speed, which meant using pairs of wires for
each signal (usually each pair was a black and a white wire, but on the
disk controllers they impressively used red and violet). ECL also was
a power hog, thus the intense cooling.
In the "front room" here is part of the disk farm and tape
library. In the foreground are some of the model 844 removable disk
drives, and just beyond are the two model
885 units (two spindles each; sealed winchester type). In the background
is the tape library, and the small rack on the left is the "cache"
where operators would hang recently used tapes prior to putting them back
in their normal location. This rack also held special tapes, like the
deadstart tapes (upper left; two redundant tapes for each Cyber).
Another view from the other side. The 885s in the foreground, all
three rows of 844s behind that. On the wall are the power panel
and TMPC panel with its infamous lamp test button.
The Cyber consoles and tape drives, also discussed elsewhere.
For reference, on the right you can see the "cache"
tape rack shown in an earlier picture. The disk farm is on the
right, out of this photo.
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