Lisp Machine Emulators?

[P. T. Withington]

On 3/20/98 11:30, Kragen wrote:

>On Fri, 20 Mar 1998, cosc19z5@bayou.uh.edu wrote:
>> In fact, are there any lisp machine emulators out there, and
>> if so from where may they be acquired?
>
>Open Genera is a sort of Symbolics LispM emulator that runs on the
>Alpha.  I don't know if it can be acquired from anyone at the moment,
>since Symbolics is bankrupt again.  It would be nice if someone could
>just give me a copy, but I don't have an Alpha.
>
>I agree that this is very important.

There are actually a number of pieces that would be nice to recover from 
the Symbolics corpse that would be ideal for this project.  One, Minima, 
is a CL implementation of an operating system with processes, networking 
and garbage collection that was originally developed under contract to 
AT&T to run on a diskless Ivory processor.  The very lowest level of run 
time, in particular the memory management is Ivory specific, but much of 
the code is pure CL.  I don't know if AT&T retained any rights to this 
work and/or if they could be persuaded to put it in the public domain.

The OG emulator is written mostly in hand-tuned Alpha assembley, but 
there was a prototype written in C.  Given a fast enough processor and 
clever enough C compiler, you could have a reasonably fast Ivory 
processor emulator.  The prototype is not as faithful an implementation 
as the Alpha assembley version, so some work would be needed.

Symbolics is currently in limbo, but it would be a great service to the 
Lisp community if the assets were put into the public domain.  
Unfortunately, the sources are the primary documentation of all the great 
work that went on there; there is very little written documentation about 
the evolution of the technology.