The IBM 608 Transistor Calculator, a plugboard-programmable unit, was the first IBM product to use transistor circuits without any vacuum tubes and is believed to be the world's first all-transistorized calculator to be manufactured for the commercial market.
[2]: 59 The development of the 608 was preceded by the prototyping of an experimental all-transistor version of the 604.
[2]: 50 To spur the adoption of transistor technology, shortly before the first IBM 608 shipped, Tom Watson directed that a date be set after which no new vacuum-tube-based products would be released.
[2]: 50 It was similar in nature of operation to the vacuum-tube IBM 604, which had been introduced a decade earlier.
[2]: 50 The use of transistors was a significant departure from the previous IBM calculators of this line.