And for a description of how to build a computer with loaded microcode you could start with Mick and Brick [1] (PDF). It describes using AMD 2900 series [2] components, the main alternative at the time was to use the TI 74181 ALU [3] and build your own microcode engine.

[1] https://www.mirrorservice.org/sites/www.bitsavers.org/compon... [2] https://en.wikipedia.org/wiki/AMD_Am2900 [3] https://en.wikipedia.org/wiki/74181