Great point about Smalltalk. It had been around a long time by the time of UCSD Pascal, and had a byte code engine from the start. Along similar lines, Burroug

Great point about Smalltalk. It had been around a long time by the time of UCSD Pascal, and had a byte code engine from the start. Along similar lines, Burroughs had a line of machines that swapped in language-specific microcode on a task-switch basis(!!!!!) so the idea of language-specific instruction sets has a long history.