Intel 4004 and the Busicom 141-PF

[Didier Lachieze]

Yes the microprocessor revolution was initiated by calculators needs.

In addition to the intel 4004 there is the Rockwell PPS-4 used in the Sharp PC-1001 and PC-1002 (and later on in pinball machines):

Quote: The PPS-4 is one of only four microprocessors introduced before 1974 (the others being Intel’s 4004 and 8008, and National Semi’s IMP-16). The PPS-4 was the only competitor to Intel 4004. And like the 4004 was originally developed for calculator applications.

(Source: http://www.antiquetech.com/?page_id=796)