John V. Blankenbaker and his legacy

John Blankenbaker started the design of a computing device in the winter of 1949 when he was a physics freshman at Oregon State College (now Oregon State University). His motivation was the need to do the calculations by using logarithms for the weekly physics lab, a very tedious job. The inspiration was an article in either Popular Mechanics or Popular Science which told about a computing device. The article said very little except that the machine used thousands of vacuum tubes but used only two digits, 0 and 1. John did not worry about the thousands of tubes but instead he concentrated on how to write numbers with only 0 and 1 and on how to do calculations with these numbers. He asked himself how he could do these things with mechanical devices such as relays. The design as it evolved was a real kludge and far too expensive for his budget but it whetted his desire to learn more about computers.

Fortunately, in the summer of 1951, John had the opportunity of working on SEAC (National Bureau of Standards Eastern Automatic Computer). He was extremely fortunate for out of the hundred students working at NBS (as it was then called) only four of us were assigned to SEAC. The computer was impressive for its size and what seemed to me to be its speed. It was kept busy solving problems for other government agencies and little time was available for an individual to use it for his personal programs. Usually, this time was during thunderstorms when the operation of the computer was unreliable. John did write one program but it failed to execute in a normal environment and even the engineers were puzzled by the failure. It was very difficult to tell what was happening when the program was running.

After graduation from OSU in 1952, John worked at Hughes Aircraft Company and was assigned to a department working on digital computers. He was asked to design the arithmetic unit for a business data processor. The department head was fond of saying that every flipflop (a bistable device capable of storing a 1 or a 0) added $500.00 to the price of the computer. So John expended a great effort on designing with a minimum number of flipflops. His experience with any computer was limited and he felt this lack deeply.

While still at Hughes Aircraft Company about 1955, John became aware that a computer needed only one flipflop if it had the appropriate simple memory. His description of such a machine appeared in 1958 in the article "Logically microprogrammed computers" in the IRE Professional Group on Electronic Computers, Vol. EC-7, No. 2, pp 103-109. Thus, he began to think there could be simple computers which could be afforded by individuals. This was in the days that even a small computer cost tens of thousands of dollars and more. John was frustrated though by the lack of a memories that he could use. The secret to the design of such a simple computer was to store the description of another computer in the memory and then to evaluate what the target machine would do when faced with a program. With one flipflop and the department head's statement that a flipflop added $500.00 to the cost, he was thinking of a computer for personal use for $500. This was his vague target.

In the fall of 1970, John found himself unemployed and he decided to investigate what might be done to make a computer for personal use. His criteria for the computer were low cost, educational, and able to give the user satisfaction with simple programs. The computer could be serial and slow which would reduce the cost yet create the environment that was desired. It should demonstrate as many programming concepts as was possible. Because of the small size, the native language of the unit would be the machine language. Above all, it had to be a stored program machine in the von Neumann sense. At no time, did he consider designing the computer in accordance with the principles of logically microprogrammed computers. Instead he decided to apply his talents to the design of a simple computer. To keep the costs low, switches and lights were the input and output of the machine. Some thought was given to punched card input but it was never developed.

The design emphasized the use of standardized parts as much as possible. The initial objective had been a parts cost of $150 per machine but the actual figure was closer to $250. In volume production, the figure of $150 might have been met. By the spring of 1971, the logic printed circuit board had been built and the computer was assembled. The memory was two MOS shift registers, each of 1,024 bits. The logic was implemented with standard small and medium scale integrated circuits. The microprocessor had not been announced yet nor would the first one been an improvement in the design.

Professionals were enthusiastic about its characteristics and everyone agreed that it was educational. Perhaps because the computer was so educational, the marketing emphasized schools and the majority of the units sold by Kenbak Corporation were to schools. Perhaps it would have been better to emphasize the fun aspects and to have pitched the marketing to individuals. There was a problem with selling to educational institutions and that was their lengthy budget cycle.

The major marketing method was to send a computer to customers who seemed to be seriously interested. At the time, a computer could be sent by UPS or via bus for about $8.00. The potential customer could keep it two weeks and then he either bought it or returned it.

Up to the time of the first public announcement in Scientific American at the start of September 1971, the business had been conducted from John's garage at 12167 Leven Lane in Los Angles. The number 167 became the first serial number. Then for about four months, the company, now incorporated as Kenbak Corporation, had rented space. At the end of this time, it moved back to his garage.

Kenbak Corporation had taken in five outside investors. More would have been desirable as the company was undercapitalized. It did not have the staying power for the long order cycle. Still it did sell something more than forty computers to markets as diverse as schools at all levels and private individuals. Units were sold into Italy, France, Spain, Mexico, and Canada. John now believe the marketing should have emphasized the private individual. There were a lot of people who wanted to learn more about computers.

Technically, the Kenbak-1 did everything that had been intended when the design started. The user reactions show that.

John was awarded many times by countless people, organizsations and magazins for his work. Here are some awards he received.

The Boston Computer Museum ran a contest in 1985 to discover the real first personal computer. The winner, as the "first advertised commercially available non-kit computer under $1000," was the Kenbak-1, designed by John V. Blankenbaker and advertised in Scientific American in 1971.
Oliver Strimpel, Director of the Museum 1986 said "We awarded the first prize to the 1971 Kenbak-1, submitted by its creator John Blankenbaker. This small machine contained an eight-bit processor built up from medium-scale and small-scale integrated circuits, and qualified as the earliest personal computer known to the judges."

The George R. Stibitz award was given to John by the Infotech Museum (American Computer Museum) Bozeman, MT in 2005. "Computer & Communications Pioneer Award. Pioneer of the First Personal Computer, The Kenbak-1"

On the occasion of the George R. Stibitz award, the Pioneers were presented with small statutes showing a cowboy using a cell phone and a laptop computer. Since the award ceremonies were held on the Montana State University campus, this blending of the local culture with technology was deemed appropriate.

My personal award for him:
John and his wife are such very friendly and nice personalities. On my first visit to John, I gave him a printed metal plate as my thanks for his invention. This plate is on his mantelpiece.