The TMS 9900 (and its predecessor, the TI 990 minicomputer) had a similar sort of idea, except back in the days of less layers of caching. https://en.wikipedia

The TMS 9900 (and its predecessor, the TI 990 minicomputer) had a similar sort of idea, except back in the days of less layers of caching. https://en.wikipedia.org/wiki/Texas_Instruments_TMS9900#Architecture https://en.wikipedia.org/wiki/Texas_Instruments_TMS9900#Arch... (Of course, those days, there weren't orders of magnitude between the time to execute a single instruction and the time to access DRAM or ROM.)