Supercomputer for rugged environments.

Some mainframe computers are so fragile that they leave the factory packed in a carton with devices to record whether the contents have ever been turned over or tipped during transit; if it turns out they have been, the warranty is void. But not the little number-cruncher developed at Sandia National Laboratories in Albuquerque, N.M. It's been designed to "shake, rattle and roll," explains Edwin Barsis, manager of Sandia's Electronic Subsystem Department. If it weren't extremely rugged, this computer would never survive the send-off it is to get as part of the on-board navigator of a cruise missile or "smart" (maneuverable) munition.

It also handles rugged computations. The no-frills version of model IV -- with three central processing unit boards--has the computing power of the well-known super-minicomputer VAX 11/780. But model IV is capable of taking up to 16 such boards, boosting computing speeds to 8 million instructions per second (mips). And the 16-processor prototypes of model V have demonstrated computational rates of between 24 and 40 mips -- roughly the equivalent of a CRAY-1 supercomputer. Yet unlike the towering CRAY-1, these Sandia Airborne Computers (SANDACs) are about the size of a shoe box and weigh between 4 and 20 pounds.

Parallel processing is the key to the computer's speed. Most computers use "serial processing," breaking down a large computational problem into a series of small steps -- like additions, multiplications or subtractions -- and tackling each sequentially. Another way to handle the series of small steps is to assign each to a different microprocessor so that they can be computed simultaneously; this is parallel processing. "The big mainframes have very little parallel processing," Barsis says. "They have parallel access to memories and things like that, but none has the capability [as SANDAC does] to have 16 processors clunking away at once.

"For the problems it is optimized to solve," Barsis says, "SANDAC operates as fast as some of our best mainframes." But SANDAC is not a mainframe or a general-purpose computer. It's an embedded computer, meaning that it's designed to be part of something that is not primarily a computer. (One example of an embedded computer is the device that controls the timer and channel selector on a programmable videocassette recorder.)

A special-purpose computer, SANDAC was specifically designed to handle navigation and guidance problems as an embedded part of a warhead-carrying reentry vehicle (such as a missile), attack helicopter or other such weapon. Not only can it survive the vibration and acceleration associated with such weapons, but it also will operate at temperatures as high as 190[deg.]F (nearly the boiling point of water).

Although SANDAC was originally expected to handle airborne navigation, Barsis notes that it appears to be equally applicable to ground navigation. And work is currently under way to make it capable of "expert vision identification," Barsis says. One such application might be used in the identification, targeting and destrcution of a specific class of enemy aircraft. Alternatively, it might help industrial robots find and discard defective products from an assembly line, or permit automated analysis of blood products.

All of the components used in the computers are commercially available. Because existing SANDACs may have a number of civilian applications, Sandia has begun releasing drawings for the system to interested companies for commercial development. Part of SANDAC's appeal, Barsis acknowledges, is its small size. As computer chips get faster, the distance a signal has to travel becomes more significant. SANDAC's compact packaging keeps signal distances short.