On October 7, 1952, IBM researchers convert an existing vacuum tube calculator, the Model 604, to use transistors. This experiment did neither shrink or speed up the desk-sized machine, but it did consume just 5% of the power that the vacuum tube-based device did. Following this successful experiment, IBM released the model 608, the first commercial transistor calculator, four years later.
October 7: A Transistor Calculator for the First Time
