Kernel LISP - how low down can it go?

Dave Hudson
Thu, 22 May 1997 10:27:24 +0100 (BST)

On Wed, 21 May 1997, Henry G. Baker wrote:

> At SMBX, we also had a language called 'LIL', which stood for 'Lisp
> Implementation Language'.  It was used to program the FEP (Front-End
> Processor) and other embedded processors.  It was -- in effect -- a C
> with parens, since I seem to recall that it had static typing.  In
> retrospect, we should have just come up with a parenthesized C, since
> it would have been nice to generate real C upon occasion.

Well, there's been discussion about the idea of using a kernel Lisp as a 
base for building a higher level system, but I can see two ways of doing 
this.  The first says that it's really just a core and everything else is 
library code that is built out of that core.  The second says that we 
really have something like the LIL language and that our higher level 
system compiles down to the implementation language.

This is really the main point of what I'm trying to understand - I know I
can take the second approach (I think PreScheme has a similar relationship
for VLisp or Scheme48) but I'm interested to know what it would cost to
take the first approach.  Would it be possible to development memory 
management/garbage collection facilities in such a system or would these 
need to be built in?

> Someone should also look into Rodney Brooks's Lisp for his
> micro-robots.  I seem to recall a version that runs on really small
> 8-bit processors.  I think that this definitely runs on bare metal.

Does anyone have any pointers for this - I'm *very* interested in the idea
of going down to 8-bit processors as well as being able to support 32, 
64, etc.