IBM System/360

The IBM System/360 (S/360) was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific. The design made a clear distinction between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the most expensive systems used microcode to implement the instruction set, which featured 8-bit byte addressing and binary, decimal and floating-point calculations.