High Quality Content by WIKIPEDIA articles! Complex instruction set computing, or CISC (pronounced / s sk/), is a computer instruction set architecture (ISA) in which each instruction can execute several low-level operations, such as a load from memory, an arithmetic operation, and a memory store, all in a single instruction. A computer based on such architecture is a complex instruction set computer (also CISC). The terms were retroactively coined in contrast to reduced instruction set computing (RISC). Examples of CISC processor families are System/360, PDP-11, VAX, 68000, and x86.