Maurice V. Wilkes

Maurice V. Wilkes, is generally considered the inventor of microcode. Wilkes cites various authors who've proposed or used microcode to implement high-performance emulators.

Wilkes is also one of the ``grandparents'' of computing. He was around the day that EDSAC became the world's first opreational general-purpose programmable computer. He is credited with saying that they ``discovered'' debugging that very same day while attempting to execute a simple program for generating a table of prime numbers (see ``The Multics System'' by Elliot I. Organick, The MIT Press 1972, pg. 127).

From instruction-set simulation and tracing