I think there were extra instructions for Lisp, it certainly ran the Gabriel Benchmarks faster than you would expect for the advertised clock speed. I only spen

I think there were extra instructions for Lisp, it certainly ran the Gabriel Benchmarks faster than you would expect for the advertised clock speed. I only spent a day talking to John Fitch about the implementation and most of that was looking at his bindings to the GUI from Lisp. Cambridge Lisp was written in BCPL which was one of the languages provided with the machine so you probably wouldn't want to completely replace the instruction set.