Powering up a module from the IBM 604: an electronic calculator from 1948

1948 was an interesting time for computing. For decades, businesses had used punch card equipment that added and sorted electromechanically. Now these electromechanical relays and counting wheels were being used to build room-filling general-purpose computers such as Harvard Mark I (1944) and IBM's SSEC (1948). But slow electromechanical mechanisms were already becoming obsolete. World War II had fostered the development of electronics and vacuum tubes for radio, radar, and navigation. Electroni...