LISP implementations on small machines

jim stephens jwsmail at
Fri Oct 4 01:56:02 CDT 2019

On 10/1/2019 7:23 PM, Mark Kahrs via cctalk wrote:
> The first implementation was done for the 7090 by McCarthy (hence CAR and
> CDR --- Contents of Address Register and Contents of Decrement Register).
> If you want to see a tiny implementation then look for the PDP-1
> implementation done by L Peter Deutsch.  There's a book chapter and then I
> found this report:
When I was at UMR a couple of students wrote a Lisp interpreter for the 
Micro 1600 running the 1621 firmware.  It had the missing feature that 
there was no garbage collect, and would die when the cells storage ran 
out.  Very quickly.

They then added paging to a 5mb dynex and used the entire space of the 
bottom platter, at 2.5mb and ran a lot longer with paging.

And they then added a firmware assist to do a couple of operations if 
they were recognized, and it supposedly ran a bit faster, but with disk 
paging, hard to tell.

I could try to dig up the source if anyone is interested and share it.  
I've got an emulator which runs the OS and firmware for the 1621 and 
it's on my list of programs to resurrect and get running.

FWIW, I had soaked up enough lisp from this and a version which ran in 
batch on the 360/50 MVT system that I knew it well enough to be 
dangerous on the Multics system at the University of Southwestern 
Louisiana, Lafayette, LA

It of course ran maclisp.  The main thing that was fun to play with 
there was macsyma.  When Professor Jerry Saltzer visited the site was 
grateful to visit with him as he had a lot to do with the system and 
macsyma in particular.

Forget Eliza and such, if you had macsyma in 1975, you'd swear you were 
talking to something out of this world.  I also remembered enough of my 
math to run it thru a lot of problems and it was able to figure them 
out, even with some trickery.

There is a version for the Multics Emulator, but I don't think the 
version I could have saved in 1975 was saved.  I hope to get that 
running at some point (most likely after someone else gets it running, 
as macsyma isn't a program for the faint hearted to try to get running).


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