How to Cook a DECstation

[Donald D Rice]

After the building air handlers failed yesterday, the temperature in my
office got up into the 90's overnight, primarily due to the VR299 monitor,
though the attached DS5000+peripherals no doubt helped.

The machine kept running with no apparent problems, but I got to wondering
about the rated operating temperatures.  In the DS5000 Operator's Guide,
under System Unit Operating Conditions, the temperature range is given as
10-40 C, 50-104 F.

Does this imply that the machines can operate indefinitely at 104 F with no
ill effects, or simply that they will not Halt and Catch Fire in this range?
Folklore says that operating temperatures above room temperature, ~ 70 F,
reduces the MTBF even if it doesn't crash the machine outright, and I've
seen the operators shut down the main campus machines if they can't keep the
temperature below about 90 F.  But from an engineering standpoint, it isn't
clear that a 30 F rise translates into a significant MTBF impact.

So, I'd like to know if DEC has anything more definitive on the operating
temperature ranges of DECstations.  Is the entire 50-104 F range really
thought to be satisfactory, or is running these guys at the high end of the
range seriously frowned upon?

It's summer in Fairbanks when it is 90 F during the day and they play baseball
at midnight without any artificial lighting, all the stores have sales that
start at midnight, and when you go biking at midnight you see people sitting
out on their lawns reading the newspaper...

Don
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Don Rice                                  Internet: ddr at flux.isr.alaska.edu
Geophysical Institute                     E-mail:   fnddr at alaska.bitnet
University of Alaska                      Phone:    (907) 474-7569
Fairbanks, AK 99775                       Loran:    64.86N 212.16E