Scope and Content Most of this collection (1950-2005, undated) represents IBM’s medium and large scale product announcements for 1965-1990, when IBM was the dominant manufacturer of mainframe products. During this time, the third generation of stored program computers was introduced and was followed by years of incredible growth. IBM’s dominant market share (estimated at 85% of the mainframe market at that time) allowed IBM to control, for many of its products, the rate at which it introduced replacement...