A New Golden Age for Computer Architecture

Each column of the array corresponded to one control line, each row was a microinstruction, and writing microinstructions was called microprogramming.39 A control store contains an ISA interpreter written using microinstructions, so execution of a conventional instruction takes several microinstructions. The early 1980s saw several investigations into complex instruction set computers (CISC) enabled by the big microprograms in the larger control stores. Ironically, modern CISC microprocessors do indeed include microcode repair mechanisms, but the main result of his paper rejection was to inspire him to work on less-complex ISAs for microprocessors—reduced instruction set computers (RISC).

Source: cacm.acm.org