Design of an Early Minicomputer

In this article, I describe the design of an early 1950s attempt to build a relatively low-cost computer, using a mechanical desktop calculator to perform the arithmetic operations. The resulting computer-one of the earliest attempts at building a "minicomputer"-could perform stored-program addition, subtraction, multiplication, and division, as well as carry out a simple decision operation based on a number comparison. To solve a problem, the operator would type in a program sequence based on the use of nine basic instructions. Total memory capacity was 400 words.