IBM 604

[1] It was an electronic unit record machine that could perform multiple calculations, including division.

[7][8] This was only an experimental machine, but its technology was used to build the IBM 608, which shipped in December 1957, and was the world's first all-transistorized electronic calculator to be mass produced.

[8] Most of the circuitry was based on modifications of circuit designs used in the earlier 603 Electronic Multiplier and was packaged in small replaceable pluggable units, each typically containing one miniature vacuum tube.

A limited number of standardized circuit designs were used, which made the product more easily manufactured and serviced.

Considerable expectations for the future of the business rested on the 604, upon which a corresponding amount of planning talent had been invested.

IBM 604 Electronic Calculator at NEMO national science museum in Amsterdam. Note plugboard control panel used to program the 604, at bottom.