IBM System/360
More info
- Owner
- IBM
- Released
- 1964
- Type
- Mainframe family
- Architect
- Gene Amdahl
- Successor
- System/370, z/Architecture
The machine family that invented backward compatibility — and whose instruction set still runs the banks sixty years on.
Before 1964 every computer model was its own world: a new machine meant rewriting every program. IBM bet around five billion dollars, more than the Manhattan Project cost, on a family in which the smallest and the largest model shared an instruction set and peripherals. Gene Amdahl was chief architect and Fred Brooks project manager — the experience of the chaotic OS/360 operating system later became the book The Mythical Man-Month.
The 360 also brought the eight-bit byte as standard, the EBCDIC character encoding, and microcode that let cheap models emulate the company's older 1401 machines. The bet paid off so thoroughly that the architecture never died: today's z/Architecture can still run code compiled for System/360.