The history of computers would have been different if John V. Atanasoff had publicized his computing machine, the ABC, in 1940. Not only would he have been recognized as one of the inventors of the electronic computer, but the small inexpensive computer would have come on line in the 1950's and 1960's. But ENIAC set the pattern of large mainframe computers which only the largest institutions could afford. These were inaccessible to the average user; only a few specialists had access, and a user had to submit his program on punch cards to the specialist. These were run as part of a "batch", and minor errors or inappropriate instructions could halt the printout. Then, the procedure would be repeated with the same delays until the process was finished.

How to make computers serve many directly was solved by MIT in the late 1950's and early 1960's. The brilliant idea is called "time-sharing" where a single computer is linked to a number of terminals, with the computer switching from one terminal to the next at high speeds, executing a portion of each user's portion at every step. Because of its high speed, the computer seemed to be giving its undivided attention to each user. This led to the establishment of commercial "time-sharing" services where the customer "buys time" on the machine paying by the minute with access by telephone line. This seemed to be the wave of the future and would indeed compete with the technological innovation which would follow, the minicomputer.

In 1957, three engineers established the Digital Equipment Corporation in an old brick wool mill in Maynard, Massachusetts. The group was led by Kenneth H. Olsen from Stratford, Connecticut. He had studied electrical engineering at MIT, and had been part of Jay W. Forrester's Digital Computer Lab when he was twenty four as research assistant. He worked on the Whirlwind research computer project, and he was determined to build a small scale version of Whirlwind, the first computer to use magnetic core memory. He had experience as an observer of IBM's production of their SAGE computer, and he felt he could do better with a smaller team effort.

Olsen with his brother Stan and a colleague, Harlan E. Andersen, with their own money and $70,000 of venture capital from American Research and Development Corporation {ARD} began production of electronic modules for computer test equipment. ARD acquired 60 percent of the stock for their capital. Three years after its founding, Digital introduced the Programmed Data Processor model 1, or PDP-1. The machine was to be a small, rugged, inexpensive real-time unit, easy to program, and available to the user to do modest tasks such as calculating payrolls or moderating a scientific experiment, when it was needed. It cost $120,000 which was modest compared to the comparable computers, and would compete with time-sharing computers.

In 1963, Digital introduced the PDP-8, the first successful minicomputer. It about the size of a refrigerator, made with transistors and magnetic cores, and cost $18,000. It ran only one program at a time and processed data in twelve-bit words, and contained only 4K words of memory. The minicomputer had arrived.