IBM System/360

The 1964 family of compatible mainframes — one architecture, many machines — the five-billion-dollar gamble that defined the industry.

Core Principles & Analysis

• Announced April 1964; the development bet was the largest in corporate history to that date.
• Its instruction set survived into IBM's modern z-series mainframes.
• Fred Brooks, its manager, wrote 'The Mythical Man-Month' from the experience.