Plotting the family tree of IBM's "mainframe" (or relatively large-scale) computers might not be as complicated or vast a task as charting the multi-century evolution of, say, the Smith or Lee families but it nevertheless requires far more than a simple linear diagram. Back around 1964, in what were still the formative years of computers, an IBM artist attempted to draw such a chart, beginning with the IBM 701 of 1952 and its follow-ons, for just a 12-year period.
Although that primitive diagram predated the legendary System/360 and its many offshoots, the IBM computer family tree drawn nearly 40 years ago shows 33 members in three main branches. Today, such a tree would be far too tall and wide to fit on a single page.
That's because over the course of the late 20th century, IBM developed and introduced a substantial number of "large" computers, processors and data processing systems. Some of these machines were unique one-offs with no further "offspring," while dozens of others were the initial members of a major product series or family.
Some of those very early pioneering machines were:
- the Automatic Sequence Controlled Calculator -- the first automatic digital calculator in the United States -- built for Harvard University in 1944;
- the IBM 603 Electronic Multiplier of 1946, the first electronic calculator ever placed into production;
- the highly successful IBM 604 Electronic Calculating Punch of 1948, which provided unmatched computational capabilities;
- the Card-Programmed Calculator (CPC) of 1949, the first IBM product designed specifically for computation centers; and,
- the first large-scale electronic computer manufactured in quantity -- the IBM 701 of 1952 -- which was IBM's first commercially available scientific computer.
Other early IBM computers included:
- the IBM 650 Magnetic Drum Calculator of 1953, the most popular computer of the 1950s;
- the IBM 702 Electronic Data Processing Machine (earlier known as the Tape Processing Machine) of 1953;
- the Naval Ordnance Research Calculator (NORC) of 1954 -- for several years the world's fastest computer;
- the IBM 705 Electronic Data Processing Machine of 1954, successor to, and with double the memory capacity of, the 702;
- the SAGE (Semi-Automatic Ground Environment) AN/FSQ-7 computers of 1956, used in the U.S. air defense system for more than a quarter of a century; and,
- the innovative IBM 305 Random Access Memory Accounting Machine (RAMAC) of 1956, which used a magnetic disk memory unit to make possible "in-line data processing" (in which all affected records were adjusted immediately after a transaction occurred).
IBM's "big iron" Data Processing Division (DPD) was formed in 1956 to focus on the development and marketing of mainframe products. And within a short time, the company had developed:
- the first commercial airline reservation system (SABRE), using IBM 7090 data processing system introduced in 1958; and
- the Stretch supercomputer (IBM 7030) delivered in 1961 -- 200 times faster than the IBM 701, 40 times faster than the IBM 709 and seven times faster than the IBM 7090.