>"The PERQ CPU was a microcoded discrete logic design, rather than a microprocessor. It was based around 74S181 bit-slice ALUs and an Am2910 microcode sequencer

>"The PERQ CPU was a microcoded discrete logic design, rather than a microprocessor. It was based around 74S181 bit-slice ALUs and an Am2910 microcode sequencer. The PERQ CPU was unusual in having 20-bit wide registers and a writable control store (WCS), allowing the microcode to be redefined.[4]" Related: Amd Am2910 Microprogram Sequencer & Application Note "Build A Microcomputer": https://www.worthpoint.com/worthopedia/amd-am2910-microprogram-sequencer-2002987785 https://www.worthpoint.com/worthopedia/amd-am2910-microprogr... 1977 Bipolar Microprocessor: http://www.bitsavers.org/components/signetics/_dataBooks/1977_Bipolar_Microprocessor.pdf http://www.bitsavers.org/components/signetics/_dataBooks/197... Implementation of microprogrammed control in FPGAs (2002): https://ieeexplore.ieee.org/document/993275 https://ieeexplore.ieee.org/document/993275