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:
Other early IBM computers included:
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: