\\M1BASL30;\M2BASB30;\M3NGR25;\M4NGR20;\M5BASI30; \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