IBM 608

{{Short description|World's first marketed all-transistorized calculator}}

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.{{cite book |last= Bashe |first= Charles J. |title=IBM's Early Computers |url= https://archive.org/details/ibmsearlycompute00bash_871 |url-access= limited |publisher= MIT |year= 1986 |page=[https://archive.org/details/ibmsearlycompute00bash_871/page/n403 386] |display-authors=etal}}{{cite book |last1=Pugh |first1=Emerson W. |last2=Johnson |first2=Lyle R. |last3=Palmer |first3=John H. |year=1991 |title=IBM's 360 and early 370 systems |publisher=MIT Press |isbn=0-262-16123-0 |url-access=registration |url=https://archive.org/details/ibms360early370s0000pugh }}{{rp|34}} Announced in April 1955,[https://web.archive.org/web/20050122185954/http://www-03.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV2214.html IBM Archives: IBM 608 calculator]{{Cite book|url=https://hdl.handle.net/2027/wu.89037555299?urlappend=%3Bseq=84|title=A survey of domestic electronic digital computing systems.|last=Weik|first=Martin H.|date=1955|publisher=Aberdeen Proving Ground, Md.|pages=61–62|hdl=2027/wu.89037555299?urlappend=%3Bseq=84 }} it was released in December 1957. The 608 was withdrawn from marketing in April 1959.

==History==

The chief designer of the circuits used in the IBM 608 was Robert A. Henle, who later oversaw the development of emitter-coupled logic (ECL) class of circuits.{{rp|59}} The development of the 608 was preceded by the prototyping of an experimental all-transistor version of the 604. Although this was built and demonstrated in October 1954, it was not commercialized.{{rp|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.{{harvnb|Bashe|1986|p=387}} This decision constrained IBM product managers, who otherwise had the latitude to select components for their products, to make the move to transistors. As a result, the successor to the IBM 650 used transistors, and it became the IBM 7070—the company's first transistorized stored-program computer.{{rp|50}}

It was similar in nature of operation to the vacuum-tube IBM 604, which had been introduced a decade earlier.{{rp|34}} Although the 608 outpaced its immediate predecessor, the IBM 607 by a factor of 2.5, it was soon rendered obsolete by newer IBM products and only a few dozen were ever delivered.{{rp|48}}{{harvnb|Bashe|1986|p=464}}