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0 pointsSymmetry11y ago0 comments

The original Lisp Machines were conventional machines with hardware features like tagged pointers that let them execute Lisp more quickly. I'm under the impression that the machine in the article is far more radical.

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lispm11y ago

They were not that conventional. The first Lisp Machines were using micro-coded processors with special instruction sets tailored for compiled and interpreted Lisp.

* tagged architecture

* stack-oriented architecture with large stack buffers

* hardware assisted GC

* support for generic Lisp operators. For example a simple + operator.

* support for basic Lisp data structures like cons cells

The result is that Lisp programs compile to very compact machine code.

ANTSANTS11y ago

I'm guessing that by "far more radical" the GP meant "directly evals s-expressions." Especially since, IIRC, that's how PicoLisp works. I don't think there is much benefit to that approach over simpler register machines, but it's an interesting idea at least.

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