[MichaelZuo]

Thanks Ken, that's pretty fascinating info. It makes me wonder if, with modern design software, a modern 64 bit CPU could be made without any microcode either.

[monocasa]

Depending on what you mean by modern, there are RISC-V cores that don't use microcode, including 64-bit OoOE cores like SonicBOOM and the T-Head C920.