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Date:Mon Jan 12 09:10:20 1993 
Subject:Re: Grandmothers and eggs 
From:Aaron Sloman 
Volume-ID:930112.02 

pop@cs.umass.edu ( Robin Popplestone ) writes:

> Date: 11 Jan 93 13:54:07 GMT
> Organization: University of Massachusetts, Amherst
>
> Since not all of us were around in the sixties, I thought it might be
> useful to point out that Ray Dunn was the person who really got POP-2
> (complete with incremental compiler) to the state of being a tool that
> worked well enough to support the work of one of the leading AI research
> groups in the world.

As one of the people who benefited from that work at the time, even
though I was at Sussex not at Edinburgh, I can confirm this.

Am I right in thinking that that version was mostly written in
assembler?

I believe Robert Rae's Wonderpop was mostly written in DEC-10
assembler, and also Julian Davies' Pop10 system?

At Sussex, Frank O'Gorman later implemented a Pop2 in a mixture of
Algol-68 and Pop2 for the ICL 1906A in the late 1970s. It was used
for a while on a vision research project led by Max Clowes, using an
ICL machine at the Rutherford Lab to which they had a remote
connection.

> An interesting question - what is the history of incremental compilation?
> We were not aware that it was done anywhere else at the time.

As far as I know, Maclisp, developed at MIT was also incrementally
compiled in the early and mid 70's, whereas other versions
(Interlisp, UCI-Lisp, .... ???) were interpreted, and giving Lisp a
bad name for speed!

I don't know whether the MIT incremental compiler work was developed
under the influence of the Edinburgh work (quite a lot of MIT people
had visited Edinburgh for the Machine Intelligence workshops in the
60s and 70s) or whether it was completely independent.

I believe the incremental compilers for Lisp in the USA used not to
garbage collect compiled functions (nor arrays?) until recently (mid
80s??) whereas compiled Pop-2 functions were already garbage
collectable by the time I met Pop-2 in 1972, and in every other Pop
system I have met.

Aaron
-- 
Aaron Sloman,
School of Computer Science, The University of Birmingham, B15 2TT, England
EMAIL   A.Sloman@cs.bham.ac.uk  OR A.Sloman@bham.ac.uk
Phone: +44-(0)21-414-3711       Fax:   +44-(0)21-414-4281