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> Did their "cpu"(?) had special circuitry for implementing lists, CAR and CDR? It was implemented in Microcode on the CPU. > Was this multi-threaded-ness som

by lispm 2y ago

> Did their "cpu"(?) had special circuitry for implementing lists, CAR and CDR? It was implemented in Microcode on the CPU. > Was this multi-threaded-ness something built-in in hardware? Some. The process scheduler was written in Lisp. See for an early example on the MIT Lisp Machine: https://github.com/mietek/mit-cadr-system-software/blob/master/src/lispm2/proces.150 https://github.com/mietek/mit-cadr-system-software/blob/mast...

dokyun 2y ago
I think you should clarify that the Lisp machines (at least the early ones that you speak of) were not 'multi-threaded' in the sense of multiprocessing--the only multiprocessing they did was running independent Lisp systems on each of their processors, if they had more than one.
- lispm 2y ago
  From the 1981 4th edition Lisp Machine Manual, page 428ff > 25. Processes > The Lisp Machine supports multi-processing; several computations can be executed "concurrently" by placing each in a separate process. A process is like a processor, simulated by software. Each process has its own "program counter", its own stack of function calls and its own special-variable binding environment in which to execute its computation. (This is implemented with stack groups, see chapter 12, page 163.) These computers could send/receive network traffic, handle the GUI, read from disk, while the user would have processes for each application and window. On my mid 1980s Symbolics 3640 I could compile a Lisp application from scratch in a Lisp REPL for half an hour, while I was using Zmacs to edit code. The practical limitations were CPU speed, memory size, disk speed and the Garbage collector. A full GC would halt everything else. Better incremental GCs helped a lot. In GNU Emacs last I tried I could not use two IELM repls executing Lisp code at the same time. One would block the rest of GNU Emacs Lisp code.
- amszmidt 2y ago
  There is a bit to much simplification here, and confusing terminology going on here. Lisp Machines did not have "processes" (as in, Unix processes); a Lisp Machine process just a function - with some special properties. The Lisp Machine only had one processor for the Lisp Machine, and it did absolutely support multi-processing and multi-threading. A good explanation can be found in the Lisp Machine manual: https://tumbleweed.nu/r/lm-3/uv/chinual.html#Processes https://tumbleweed.nu/r/lm-3/uv/chinual.html#Stack-Groups Which is also where all current work on the MIT Lisp Machine is being done. :-)
  - medo-bear 2y ago
    All current work ?

by lispm 2y ago

dokyun 2y ago

I think you should clarify that the Lisp machines (at least the early ones that you speak of) were not 'multi-threaded' in the sense of multiprocessing--the only multiprocessing they did was running independent Lisp systems on each of their processors, if they had more than one.

lispm 2y ago
From the 1981 4th edition Lisp Machine Manual, page 428ff > 25. Processes > The Lisp Machine supports multi-processing; several computations can be executed "concurrently" by placing each in a separate process. A process is like a processor, simulated by software. Each process has its own "program counter", its own stack of function calls and its own special-variable binding environment in which to execute its computation. (This is implemented with stack groups, see chapter 12, page 163.) These computers could send/receive network traffic, handle the GUI, read from disk, while the user would have processes for each application and window. On my mid 1980s Symbolics 3640 I could compile a Lisp application from scratch in a Lisp REPL for half an hour, while I was using Zmacs to edit code. The practical limitations were CPU speed, memory size, disk speed and the Garbage collector. A full GC would halt everything else. Better incremental GCs helped a lot. In GNU Emacs last I tried I could not use two IELM repls executing Lisp code at the same time. One would block the rest of GNU Emacs Lisp code.
amszmidt 2y ago
There is a bit to much simplification here, and confusing terminology going on here. Lisp Machines did not have "processes" (as in, Unix processes); a Lisp Machine process just a function - with some special properties. The Lisp Machine only had one processor for the Lisp Machine, and it did absolutely support multi-processing and multi-threading. A good explanation can be found in the Lisp Machine manual: https://tumbleweed.nu/r/lm-3/uv/chinual.html#Processes https://tumbleweed.nu/r/lm-3/uv/chinual.html#Stack-Groups Which is also where all current work on the MIT Lisp Machine is being done. :-)
- medo-bear 2y ago
  All current work ?