/FONT#1=BASL30/FONT#2=BASB30/FONT#3=NGR25/FONT#4=NGR20/FONT#5=BASI30
␈↓↓␈↓α␈↓β␈↓∧␈↓¬␈↓ ↓H
␈↓↓␈↓ ε↓Sept 14, 1978␈↓ ↓H
␈↓ ↓H
␈↓ ↓H
␈↓ ↓H
Carl Helmers, Editor-in-Chief␈↓ ↓H
Byte Publications␈↓ ↓H
70 Main St.␈↓ ↓H
Peterborough HH, 03458␈↓ ↓H
␈↓ ↓H
Dear Carl:␈↓ ↓H
␈↓ ↓H
␈↓ ↓HAre␈α∂you␈α∂still␈α∂interested␈α∂in␈α∂some␈α∂BYTE␈α∂articles␈α∂on␈α∞LISP?␈α∞Are␈α∞you␈α∞still␈α∞interested␈α∞in␈α∞some␈α∞BYTE␈↓ ↓H
␈↓ ↓Harticles␈α∞on␈α∞LISP␈α∞from␈α∞␈↓αme␈↓↓?␈α∞I␈α∞am␈α
resurrecting␈α
my␈α
"LISP-for-the-micros"␈α
articles␈α
and,␈α
since␈α
you␈α
had␈↓ ↓H
␈↓ ↓Hbegun␈α
work␈α
on␈α
them,␈α
thought␈α
you␈α
should␈α
have␈α
right␈α
of␈α
first␈α
refusal.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HI␈α∪can␈α∪assure␈α∪you␈α∪that␈α∩this␈α∩time␈α∩the␈α∩process␈α∩wil␈α∩be␈α∩smoother.␈α∩Before␈α∩I␈α∩was␈α∩doing␈α∩battle␈α∩with␈↓ ↓H
␈↓ ↓HMcGraw-Hill␈αand␈αHewlett-Packard.␈αMcGraw-Hill␈αdecided␈αto␈αuse␈αmy␈αbook␈αand␈αmy␈αknowledge␈αas␈α
"an␈↓ ↓H
␈↓ ↓Hexperiment␈α∞in␈α∞computer␈α∞typesetting".␈α
One␈α
of␈α
their␈α
minions␈α
was␈α
supposed␈α
to␈α
take␈α
my␈α
machine-text,␈↓ ↓H
␈↓ ↓Hwith␈α⊃instructions␈α⊃from␈α⊃me,␈α⊃and␈α⊂develp␈α⊂the␈α⊂translation␈α⊂process;␈α⊂he␈α⊂was␈α⊂a␈α⊂"computer␈α⊂expert".␈α⊂Six␈↓ ↓H
␈↓ ↓Hmonths␈αlater␈αhe␈αwas␈αstill␈αflying␈αaround␈αthe␈αcountry,␈αlooking␈αfor␈αa␈αsoftware␈αhouse␈αwhich␈αcould␈αwrite␈↓ ↓H
␈↓ ↓Hthe␈α
program;␈αit␈αsoon␈αbecame␈αclear␈αthat␈αhe␈αhad␈αnot␈αeven␈αread␈αthe␈αinstruction␈αI␈αhad␈αprepared.␈αMore␈↓ ↓H
␈↓ ↓Hupsetting,␈αit␈αwas␈αclear␈αthat␈αthis␈αschedule␈αwould␈αdelay␈αthe␈αpublishing␈αdate␈αto␈αthe␈αnext␈αacademic␈αyear.␈↓ ↓H
␈↓ ↓HTherefore,␈α⊃the␈α⊃only␈α⊃way␈α⊃it␈α⊂wold␈α⊂get␈α⊂done␈α⊂was␈α⊂if␈α⊂I␈α⊂did␈α⊂it␈α⊂myself␈α⊂in␈α⊂the␈α⊂very␈α⊂wee␈α⊂hours␈α⊂of␈α⊂the␈↓ ↓H
␈↓ ↓Hmorning;␈α
that␈α
did␈α
not␈α
please␈α
me␈α
at␈α
all.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HFinally,␈α∩I␈α∩wrote␈α∩the␈α∩typesetting␈α∩program␈α∩for␈α∩McGraw-Hill;␈α⊃was␈α⊃assured␈α⊃by␈α⊃the␈α⊃compositor␈α⊃that␈↓ ↓H
␈↓ ↓Heverything␈α∞was␈α∞ok,␈α∞and␈α∞punched␈α∞twenty-four␈α∞boxes␈α
of␈α
paper␈α
tape,␈α
only␈α
to␈α
discover␈α
that␈α
they␈α
were␈↓ ↓H
␈↓ ↓Hunable␈α
to␈α
generate␈α
consistent␈α
output.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HSimultaneously,␈αI␈αwas␈αtrying␈αto␈αconvince␈αthe␈α"research␈αlab"␈αof␈αHP␈αthat␈αbatch-processing␈αsystems␈αare␈↓ ↓H
␈↓ ↓Hinferior␈αto␈αconversational␈αsystems;␈αthat␈α2400␈αbaud␈αglass␈αteletypes␈αare␈αnot␈αinteractive␈αdisplays;␈αthat␈α
an␈↓ ↓H
␈↓ ↓HHP3000␈α
is␈α
␈↓αnot␈↓↓␈α
a␈α
"machine␈α
like␈α
the␈α
PDP-10,␈α
but␈α
with␈α
16-bit␈α
words"␈α(the␈αmanager␈αof␈αthe␈αadvanced␈↓ ↓H
␈↓ ↓Hsoftware␈α⊂section␈α⊂actually␈α⊂said␈α⊂that␈α⊂to␈α⊂John␈α⊂McCarthy!);␈α⊂that␈α⊂if␈α⊂I␈α⊂was␈α⊂to␈α⊂build␈α∂a␈α∂machine␈α∂which␈↓ ↓H
␈↓ ↓Hexecuted␈α∂LISP␈α∂well␈α∂and␈α∂was␈α∂attractive␈α∂to␈α∂the␈α∞AI␈α∞community,␈α∞the␈α∞project␈α∞would␈α∞need␈α∞staff␈α∞which␈↓ ↓H
␈↓ ↓Hunderstood␈α
these␈α
problems.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HThis␈α⊃is␈α⊃the␈α⊃kind␈α⊃of␈α⊃turmoil␈α⊃which␈α⊃you␈α⊃walked␈α⊃into;␈α⊃both␈α⊃problems␈α⊃have␈α⊃been␈α⊂resolved:␈α⊂I␈α⊂told␈↓ ↓H
␈↓ ↓HMcGraw-Hill␈α
to␈α
forget␈α
their␈α"computer␈αexperiment"␈αand␈αuse␈αthe␈αXGP␈αoutput;␈αI␈αquit␈αat␈αHP.␈αNow␈αI␈↓ ↓H
␈↓ ↓Hwould␈αlike␈αto␈αreturn␈αto␈αthe␈αpleasurable␈αtask␈αof␈αdescribing␈αthe␈αbenefits␈αof␈αLISP-like␈αlanguages␈αto␈αthe␈↓ ↓H
␈↓ ↓Hpersonal␈αcomputer␈αcrowd.␈αI␈α
have␈α
been␈α
following␈α
the␈α
Pascal␈α
articles␈α
in␈α
BYTE␈α
with␈α
some␈α
interest␈α
(and␈↓ ↓H
␈↓ ↓Hamusement).␈α
I␈α
would␈α
like␈α
the␈α
opportunity␈α
to␈α
present␈α
my␈α
LISP␈α
philosophy␈α
as␈α
a␈α
contrasting␈α
position.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HThe␈α
programming␈α
task␈α
is␈α
one␈α
of␈α
the␈α
most␈α
difficult␈α
human␈α
enterprises.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HExploratory␈α∂programming,␈α∂which␈α∂is␈α∂the␈α∂halmark␈α∂of␈α∂AI␈α∂and␈α∂to␈α∂a␈α∂very␈α∂large␈α∂extent␈α∂occurs␈α∞in␈α∞the␈↓ ↓H
␈↓ ↓Hcreative␈α∩stages␈α⊃of␈α⊃any␈α⊃programming␈α⊃task,␈α⊃is␈α⊃best␈α⊃done␈α⊃with␈α⊃a␈α⊃un-typed␈α⊃language.␈α⊃Strong␈α⊃typed␈↓ ↓H
␈↓ ↓Hlanguages␈α
only␈α
confuse␈α
and␈α
obfuscate␈α
the␈α
formulative␈α
stages.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HWe␈α∪must␈α∪put␈α∪a␈α∪stronger␈α∪emphasis␈α∪on␈α∪the␈α∪education␈α∪of␈α∪programmers,␈α∩rather␈α∩than␈α∩restrict␈α∩the␈↓ ↓H
␈↓ ↓Hexpressive␈αpowers␈αof␈αthe␈αlanguages.␈αConsider␈αthe␈αtools␈αof␈αa␈αmore␈α
traditional␈α
craftsman:␈α
in␈α
the␈α
hands␈↓ ↓H
␈↓ ↓Hof␈αan␈αamateur␈αthose␈αtools␈αcan␈αbe␈αdeadily,␈αwhereas␈αthe␈αcraftsman␈αcan␈αdevelop␈αexquisite␈αobjects.␈αDoes␈↓ ↓H
␈↓ ↓Hone␈αpropose␈αthat␈αall␈αtools␈αbe␈αdulled␈αappropriately␈αso␈αthat␈αthe␈αamateurs␈αcannot␈αdo␈αthemselves␈α
injury?␈↓ ↓H
␈↓ ↓HNo,␈α∪we␈α∪educate␈α∪them␈α∪in␈α∪the␈α∪proper␈α∩use␈α∩and␈α∩respect␈α∩for␈α∩the␈α∩instruments␈α∩and␈α∩expect␈α∩that␈α∩the␈↓ ↓H
␈↓ ↓Hcraftsman's␈αtool␈αremain␈αsharp.␈αThe␈αemphasis␈αis␈αproperly␈αplaced␈αon␈αthe␈αindividual.␈αI␈αdon't␈αadvocate␈↓ ↓H
␈↓ ↓Hthat␈α∞programmers's␈α
who␈α
produce␈α
buggy␈α
code␈α
be␈α
shot,␈α
but␈α
I␈α
do␈α
insist␈α
that␈α
we␈α
take␈α
better␈α
efforts␈α
to␈↓ ↓H
␈↓ ↓Heducate␈αour␈αpeople.␈αIn␈αthis␈αregard,␈αI␈αfind␈αthe␈αPascal␈αapproach␈α
a␈α
false␈α
temptress;␈α
do␈α
not␈α
dull␈α
the␈α
tools␈↓ ↓H
␈↓ ↓Hof␈αthe␈αprogrammer␈αby␈αappealling␈αarguments␈αfast␈αparsing␈αalgorithms␈αand␈αefficient␈αcompilers;␈αdo␈αnot␈↓ ↓H
␈↓ ↓Hconfuse␈α⊃education␈α⊃with␈α⊃the␈α⊃mass-merchandizing␈α⊃of␈α⊃armies␈α⊃of␈α⊂programmers␈α⊂whose␈α⊂competence␈α⊂is␈↓ ↓H
␈↓ ↓Hsealed␈α
in␈α
a␈α
cautious,␈α
uncreative␈α
world␈α
of␈α
dull␈α
tools.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HRather␈α∪be␈α∪seduced␈α∪by␈α∪LISP,␈α∪whose␈α∪bizarre␈α∪advocates␈α∪have␈α∪created␈α∩some␈α∩of␈α∩the␈α∩most␈α∩elegant␈↓ ↓H
␈↓ ↓Hcomputer␈α⊃related␈α⊃products.␈α⊂Not␈α⊂everyone␈α⊂should␈α⊂program␈α⊂in␈α⊂LISP;␈α⊂in␈α⊂fact,␈α⊂not␈α⊂everyone␈α⊂should␈↓ ↓H
␈↓ ↓Hprogram.␈αHowever␈αthe␈αAI␈αcommunity␈αis␈αthe␈αcraft␈α
of␈α
the␈α
tool␈α
builder;␈α
their␈α
tools␈α
are␈α
the␈α
sharpest␈α
and␈↓ ↓H
␈↓ ↓Hmost␈α
incisive␈α
of␈α
the␈α
computer␈α
field.␈α
It␈α
is␈α
this␈α
kind␈α
of␈α
tool␈α
which␈α
appeals␈α
to␈α
the␈α
personal␈α
computer␈↓ ↓H
␈↓ ↓Hperson.␈α∞It␈α∞is␈α∞not␈α∞the␈α∞elegance␈α∞of␈α∞BASIC␈α∞which␈α∞has␈α∞made␈α∞it␈α∞the␈α∞standard␈α∞language;␈α∞it␈α
is␈α
BASIC's␈↓ ↓H
␈↓ ↓Hinteractive␈α
nature,␈α
allowing␈α
quick␈α
experimentation␈α
with␈α
programming␈α
ideas,␈α
which␈α
accounts␈α
for␈αits␈↓ ↓H
␈↓ ↓Hlongevity.␈αMuch␈αof␈αthis␈αinteractive␈αflavor␈αcan␈αbe␈αgrafted␈αonto␈αan␈αPascal-like␈α
language,␈α
but␈α
the␈α
result␈↓ ↓H
␈↓ ↓His␈α
much␈α
inferior␈α
to␈α
what␈α
one␈α
can␈α
expect␈α
from␈α
a␈α
true␈α
interactive␈α
language␈α
like␈α
LISP.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HIn␈α
fact,␈α
the␈α
spirit␈α
which␈α
created␈αPascal␈αwas␈αopposed␈αto␈αinteractive␈αcomputation:␈αWirth,␈αin␈αthe␈α1969␈↓ ↓H
␈↓ ↓HSoftware␈αEngineering␈αConference␈αsaid␈α␈↓¬"I␈αwould␈αlike␈αto␈αdiscuss␈αthe␈αtrend␈αtowards␈αconversationality␈αin␈↓ ↓H
␈↓ ↓Hour␈αtools.␈αThere␈αhas␈αbeen,␈αsince␈αthe␈αdevelopment␈αof␈αtimesharing␈αand␈αon-line␈αconsoles,␈αa␈α
very␈α
hectic␈α
trend␈↓ ↓H
␈↓ ↓Htowards␈α⊃development␈α⊃of␈α⊂systems␈α⊂which␈α⊂allow␈α⊂the␈α⊂interactive␈α⊂development␈α⊂of␈α⊂programs.␈α⊂Now␈α⊂this␈α⊂is␈↓ ↓H
␈↓ ↓Hcertainly␈α⊃nice␈α⊃in␈α⊃a␈α⊃way,␈α⊃but␈α⊃it␈α⊂has␈α⊂its␈α⊂dangers,␈α⊂and␈α⊂I␈α⊂am␈α⊂particularly␈α⊂wary␈α⊂of␈α⊂them␈α⊂because␈α⊂this␈↓ ↓H
␈↓ ↓Hconversational␈αusage␈αhas␈αnot␈αonly␈αgained␈αacceptance␈αamong␈αsoftware␈αengineers␈αbut␈αalso␈αin␈αuniversities␈↓ ↓H
␈↓ ↓Hwhere␈α∞students␈α
are␈α
trained␈α
in␈α
programming.␈α
My␈α
worry␈α
is␈α
that␈α
the␈α
facility␈α
of␈α
quick␈α
response␈α
leads␈α
to␈↓ ↓H
␈↓ ↓Hsloppy␈αworking␈αhabits␈αand,␈αsince␈αthe␈αstudents␈αare␈αgoing␈αto␈αbe␈αour␈α
future␈α
software␈α
engineers,␈α
this␈α
might␈↓ ↓H
␈↓ ↓Hbe␈α
rather␈α
detrimental␈α
to␈α
the␈α
field␈α
as␈α
a␈α
whole".␈↓↓␈↓ ↓H
␈↓ ↓H
␈↓ ↓HWirth␈αmay␈αhave␈αmodified␈αhis␈αposition␈αsince␈αthen,␈αbut␈αat␈αleast␈αwhen␈αPascal␈αwas␈αformulated,␈αhe␈αwas␈↓ ↓H
␈↓ ↓Hnot␈αa␈αstrong␈αadvocate␈αof␈αinteractive␈αprogramming.␈α
Many␈α
of␈α
the␈α
decisions␈α
and␈α
compromises␈α
of␈α
Pascal␈↓ ↓H
␈↓ ↓Hare␈α⊂a␈α⊂result␈α⊂of␈α⊂his␈α⊂view␈α⊂of␈α⊂computation.␈α⊂I␈α⊂feel␈α⊂it␈α⊂is␈α⊂important␈α∂that␈α∂the␈α∂personal␈α∂computer␈α∂users␈↓ ↓H
␈↓ ↓Hunderstand␈α⊃that␈α⊂they␈α⊂need␈α⊂not␈α⊂give␈α⊂up␈α⊂the␈α⊂interactiveness␈α⊂of␈α⊂BASIC␈α⊂to␈α⊂gain␈α⊂the␈α⊂structure␈α⊂and␈↓ ↓H
␈↓ ↓Hportability␈α_which␈α_Pascal␈α_is␈α_advertising;␈α_LISP␈α_offers␈α_both.␈α_LISP␈α↔is␈α↔␈↓αnot␈↓↓␈α↔a␈α↔special␈α↔purpose␈↓ ↓H
␈↓ ↓Hlist-processing␈α≤language,␈α≠as␈α≠MACSYMA's␈α≠arithmetic,␈α≠Teitleman's␈α≠development␈α≠system,␈α≠and␈↓ ↓H
␈↓ ↓HGreenblatt's␈α∀LISP␈α∀machine␈α∀demonstrate.␈α∀Its␈α∪compilers␈α∪can␈α∪be␈α∪as␈α∪good␈α∪as␈α∪any␈α∪other␈α∪language␈↓ ↓H
␈↓ ↓Hprocessor;␈α
its␈α
development␈α
systems␈α
are␈α
far␈α
superior␈α
to␈α
those␈α
of␈αother␈α(well-known)␈αlanguages;␈αit␈αcan␈↓ ↓H
␈↓ ↓Hbe␈αused␈αas␈αan␈αeffective␈αsystems␈αprogramming␈αlanguage,␈αas␈αwell␈αas␈αbeing␈αthe␈α
entry␈α
point␈α
for␈α
all␈α
of␈α
AI␈↓ ↓H
␈↓ ↓Hand␈α
much␈α
of␈α
the␈α
theory␈α
of␈α
computation.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HI␈αkept␈αthe␈αedited␈αmanuscript␈αwhich␈αyou␈αreturned␈αto␈αme;␈αI␈αam␈αready␈αto␈αrewrite␈α
that␈α
initial␈α
article␈α
and␈↓ ↓H
␈↓ ↓Hsupply␈α∃a␈α∃total␈α∃of␈α∃about␈α∃six,␈α∃covering␈α∀most␈α∀of␈α∀the␈α∀details␈α∀of␈α∀LISP␈α∀programming␈α∀and␈α∀micro␈↓ ↓H
␈↓ ↓Himplementations.␈↓ ↓H
␈↓ ↓H
␈↓ ↓HI'm␈α
sorry␈α
that␈α
our␈α
past␈α
attempts␈α
at␈α
communication␈α
have␈α
been␈α
so␈α
noisy;␈α
I␈α
hope␈α
that␈α
we␈α
can␈α
try␈α
again.␈↓ ↓H
␈↓ ↓H␈↓ εW
␈↓ εW
Yours sincerely,␈↓ εW
␈↓ εW
␈↓ εW
␈↓ εW
John R. Allen␈↓ εW
18215 Bayview Dr.␈↓ εW
Los Gatos Ca. 95030␈↓ εW
408 353-2227␈↓ εW
␈↓ ↓H