Hybrid computation: What is it? Who needs it?

Simulation of complex engineering systems is a growing need. The hybrid computer — evolved from the analog and digital computer — offers a means, otherwise impractical, for achieving many such simulations During the 1950s the capabilities of electronic computers stayed well ahead of the needs of the average user. Such was the case in both the analog computer and scientific digital computer fields. One effect of this situation was the formation of two schools of experts with opposite views on the choice of the “best” general-purpose scientific computer. Differences of training, experience, and semantics led to a serious barrier to interchange of opinion between these two groups. At best, the fashionable middle-of-the-road position was to admit that each computing technique “had its place,” which did little to break down the barrier. Only with the appearance of a computational task that could not be accomplished satisfactorily by either type was the barrier cracked and a small opening made.