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\F1\CMar 23, 1980



Mr. Bob Fairbairn
Software Manager
Commodore Corporation
3330 Scott Blvd.
Santa Clara, CA  95051


Dear Mr Fairbairn:

\JIt was a pleasure to talk with you last week. As suggested, I am enclosing
some material on LISP, The LISP Company, and myself. Perhaps the combination
of ingredients will shed some light on LISP. Below is some general information
about LISP and its applications;
the second part of the letter outlines my reason for approaching Commodore.
\.



\C\F2LISP\F1
\J
LISP is an old programming language, second only to Fortran in longevity.
LISP is still the major language in the field known as Artificial Intelligence.
Artificial Intelligence deals with the problems of understanding and
mimicing intelligent behavior using computers. A major branch of Artificial
Intelligence (AI), called  "knowledge engineering",  strives to raise the
general level of usefulness of computers by building understanding
and expertise into computing systems; I am enclosing a short article
from a recent San Francisco newspaper, describing some
applications. 

Until very recently, such systems
were the sole province of research establishments, since the programming of such
systems involved large expensive  computing facilities.
Recent technological developments have changed the picture significantly;
the newer microprocessors are capabable of handling a suprisingly large class
of these applications in an inexpensive manner; further, the size of the 
packaged product can be pleasantly small.
Almost all of these applications are written in LISP, or in a specialized
language which itself is written in LISP; that is, LISP is also a
language for writing other programming systems. LISP's dominance in AI
programming derives in part from its representation of data; besides the typical
numerical operations, LISP also manipulates complex tree-like structures.
These structures are convenient for representing interrelationships
between objects; for example, one can view our ability to use our memory
effectively as a scheme wherein pieces of information are interconnected by
 links to other pieces of information. This view of memory can be 
effectively encoded into LISP structures. These representations make up
the inner structure of these "expert" systems. One further application, 
of these ideas is the construction of intelligent data bases. Traditional
data base query and insertion involves the encoding of requests in a 
fashion more akin to the machine than the human; AI techniques 
could do much to improve the situation.

Summary: There is a large body of programs  that improve the user/machine
interface (natural language understanding, "expert systems") which are
written in LISP and would enhance any computing system, particularly one
oriented to casual or novice users.

LISP has been applied quite successfully outside the AI domain.
It has been the major implementation language for "algebraic manipulation"
systems (MACSYMA and REDUCE, for example). These systems manipulate
algebraic expressions much like a hand calculator manipulates numeric
values  I have marked an article in the enclosed BYTE magazine, dealing with
such algebraic  manipulation  systems. These systems are not simply
research toys; REDUCE was constructed by a working physicist because the
algebraic expressions with which  he worked became too complex to 
manipulate by hand, and numerical methods were not appropriate.
MACSYMA is used daily by engineers, mathematicians, and physicists over
the ARPAnet. 

Summary: Algebraic manipulations systems written in LISP supply tools for
working professionals that cannot be obtained by other means. These
systems can be transported to the small computer system.

LISP is gaining popularity as a general purpose programming language
both in industry and in the university.
Until very recently, LISP was a "cult" language because little attempt
was made to popularize it (to some extent this followed from the
expensive computing support that older LISPs  expected).
I published the first (and still only) book that gave a comprehensive
treatment of LISP at the university level. That book has done quite
well, now being translated into Japanese. The Japanese LISP community is the
most advanced in the world; their  government has committed
substantial resources to AI and LISP, with at least six LISP machine
projects underway in Japan at this time. Japanese universities are
beginning to use LISP as the major programming language for their universities.

Summary: LISP is becoming a popular general purpose language in this country;
LISP is already a very popular language in Japan.

A recent development in this country should expand LISP's popularity here.
The new Department of Defense language, called ADA, was described by its
sponsor as "something like Pascal ... something like LISP"; so
understanding LISP and Pascal should improve one's view of ADA. The last
DOD-sponsored  language was COBOL; we can expect similar growth with ADA.
Further, the ADA team that is responsible for the "programming environment"
is using LISP's experience as their primary model. A "programming environment"
is the collection of tools --editors, compilers, debuggers, etc,-- that
surround a language. LISP, because of the kind of programming that it
was designed for, is a very "interactive" language. The program development
facilities of a production LISP are quite sophisticated and helpful.
When one writes programs in  AI, it is often not exactly clear what  
the program should
do; after all, intelligent behavior is often hard to ellicit in everyday life.
In AI we program in a very "cut-and-try" fashion, not because we're 
necessarily sloppy, but because the phenomenon is not well-understood.
The result is that an AI programming language must allow easy and rapid 
modification of programs and data.
The ADA team understands that ADA will be used for programming tasks as complex
as those tackled by LISP and therfore will be incorporating LISP's ideas
into their work.

Summary: LISP will have significant impact on the new DOD language, ADA.
The ADA programming environment will have many characteristics developed
from LISP.
An understanding of LISP should help appreciate ADA.
\.




\C\F2Proposal\F1
\J
I wish to do for LISP what UCSD did
for Pascal: that is, supply the \F5de facto\F1 standard LISP for microcomputers,
and to the extend possible, supply the standard for larger machines.
Such an operation requires the availability of an inexpensive, comprehensive
LISP implementation, together with a 
book that teaches LISP to one who has  access to this implementation.
The project will not succeed  unless \F2both\F1 factors are taken into account
successfully. Instead of pursuing this goal within a university I
would like to carry it off as a commercial venture.
A natural way to proceed is to involve a major force in small computers
at the initial step, while securing a publisher for the book part of the
enterprise. BYTE Books is seriously interested in that aspect; the question is:
is Commodore interested in the computational part?

I have just completed the first version of TLC-LISP for Cromemco on their
Z-80; we are currently modifying it to run under CP/M, and will
be marketing that version ourselves. 
Since proper hardware was not available, we have not (yet) built the LISP
programming environment; the initial offering is only the language.
I am enclosing a short description of
that language; it is a subset of the LISP that was designed for the
MIT LISP machine. Our LISP is by far the most professionally crafted of the
LISP's available on today's micros; we expect  LISP will really "shine" when
it becomes available on the newer sixteen-bit machines. 

If you desire more information, please give me a call.
I will be in Texas the first week in April, but expect to be available
otherwise (except that I will be in-and-out a lot handling the LISP Conference
business).
\.
\←L\→S\←R\-L\/'2;\+L\→L

Yours sincerely,


John R. Allen
Founder, The LISP Company
PO Box 487
Redwood Estates Ca, 95044
(408) 353-2227

\←S\→L