The IBM System/360 (S/360) was a mainframe computer system family announced by IBM on April 7, 1964, and delivered between 1965 and 1978.[1] 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 incompatible model 44 and the most expensive systems used microcode to implement the instruction set, which featured 8-bit byte addressing and binary, decimal and (hexadecimal) floating-point calculations.