The the late 1960s and early 70s, there was much talk about "generations" of computer technology. This photo illustrates what were commonly known as the three generations:
Omitted from this taxonomy is the "zeroth" generation computer based on metal gears, such as the ancient Greek Antikythera mechanism, the Babbage Difference and Analytical Engines (1820s-1830s), the 1890 census tabulator, and the Harvard/IBM Mark I (1940-43). Or on electromechanical relays, such as the Harvard Mark II and the Bell Labs Relay Computers (1939-51).
Other generations were to follow: the fourth (1971-1980) based on Very Large Scale Integrated (VLSI) circuits such as the Digital Equipment Corporation PDP-10, PDP-11, and DECSYSTEM-20, and the IBM PC and PC/AT. And then a fifth based on Ultra Large Scale Integration (ULSI) and parallel processing (21st Century laptops, notebooks, tablets, etc). And then whatever else comes next, e.g. quantum computers. In any case, at this point (2021) the average cell phone or "smart watch" has more memory and computing power and speed than our third-generation IBM 360/91 did, which sold for millions of dollars and occupied acres of floor space.
|Columbia University Computing History||Frank da Cruz / email@example.com||This page created: January 2001||Updated: 20 April 2021|