Military computer

This article specifically addresses US armed forces military computers and their use.

Some of the earliest computers were military computers. Military requirements for portability and ruggedness led to some of the earliest transistorized computers, such as the 1959 AN/MYK-1 (MOBIDIC), the 1960 M18 FADAC, and the 1962 D-17B; the earliest integrated-circuit based computer, the 1964 D-37C; as well as one of the earliest laptop computers, the 1982 Grid Compass. Military requirements for a computer small enough to fit through a submarine's hatch led to the AN/UYK-1.

Typically a military computer is much more robust than an industrial computer enclosure. Most electronics will be protected with a layer of conformal coating. There will be more structure inside to support the components, the plug-in cards will be individually supported and secured to assure they do not pop out of their sockets, the processor and heat sink will be secured, memory will be glued into their sockets, and so forth. This is to assure nothing moves during the shock events.

There are several differentiators between military computers and typical office or consumer computers:

Cost – Military computers are generally much more expensive than office/consumer computers. Consumer computers from manufacturers such as Dell are manufactured in very high quantities which leads to lower costs due to economy of scale. Military programs, on the other hand, can require small numbers of systems leading to higher costs. Military computers will typically also be constructed of more robust materials with more internal structure, more cooling fans, a more robust power supply, and so forth.

Intended Environment – An office or consumer computer is intended for use in a very controlled shirt-sleeve environment with moderate temperatures and humidity and minimal dust. A military computer can be designed to operate in very adverse environments with extremes of temperature such as -20C to +65C operating, 5% to 95% humidity levels, and high dust loading in the air as well as other insults to the hardware. They may be required to operate in high salt environments such as on a ship or designed for high shock and vibration such as on a ship or submarine. Military computers may be intended for installation on aircraft in which case they need to be crash worthy and able to operate at high altitudes if in unpressurized aircraft. The same computer may be required to operate in Afghanistan as well as in Alaska with no change in the design.

...
Wikipedia