This Day in Tech History

On This Day . . .

From Over 1 Million to $4.61


October 7, 1954: First Transistor Calculator

IBM researchers modify an existing model 604 vacuum tube calculator to use transistors. This experiment didn’t shrink the desk-sized machine nor make it any faster, but it did use only 5% of the power the vacuum tube-based design did. Encouraged by this successful experiment, IBM introduced the first commercial transistor calculator 4 years later, the model 608. In todays money it would cost you over 1 million . . . or you could rent one in 1948 at $645 per month (1948 dollars).


The IBM 604 was a control panel programmable Electronic Calculating Punch introduced in 1948, and was a machine on which considerable expectations for the future of IBM were pinned and in which a corresponding amount of planning talent was invested.

The calculation unit contained 1,400 tubes. The 604 performed fixed point addition, subtraction, multiplication and division using BCD arithmetic.


IBM vacuum tube – To the right a tube module



IBM 604 – calculator unit on the left – punch card unit on the right

Initial versions supported 40 program steps, and this was soon expanded to 60. Processing was still locked to the reader/punch cycle time, thus program execution had to complete within the time between a punched card leaving the read station and entering the punch station.


IBM 608

An all-transistor version of the 604 was built and demonstrated in October 1954. Although it used 2000 transistors as opposed to 1250 tubes in the original, it occupied only half the volume, and used only 5% as much power. This was only an experimental machine, but its technology was used to build the IBM 608, which shipped in December 1957, and was the first solid-state computing product to be commercialized.


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