<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 }
--></style><title>Re: Sketchpad in Squeak</title></head><body>
<div>Alan Borning did a Sketchpad influenced advance on constraint
programming in 1977 in Smalltalk-76. This code is around and several
people have come close to getting it going again in Squeak.</div>
<div><br></div>
<div>"Hard" is one of those interesting words. Ivan's
Sketchpad thesis is gettable from MIT in pdf form, and it is quite
impressive even by today's standards. 40+ years later it should be a
nice master's thesis for some supergradstudent. But it would be still
be a fair amount of work from scratch, even though Ivan had to program
even the line drawing on the TX-2, he had to figure out, design, and
build in macroassembler on a half MIP machine he could only use about
3 hours a day ..... A fabulous Squeak programmer who understands just
how Sketchpad worked (this is known) could probably replicate the
original Sketchpad in 1-2 months of work (somebody please prove me too
pessimistic). OTOH, the "math" and general object model of
Sketchpad was very (profoundly) simple, so a very clean approach to
what it was trying to do, coupled with powerful computing so no
serious optimizations would be required, could be a lot simpler for an
expert. Doing the iconic UI (the original one) well would still be a
bit of a challenge....</div>
<div><br></div>
<div>Cheers,</div>
<div><br></div>
<div>Alan</div>
<div><br></div>
<div>------</div>
<div><br></div>
<div>At 7:21 PM -0400 6/12/03, Brent Vukmer wrote:</div>
<blockquote type="cite" cite>content-class:
urn:content-classes:message<br>
Content-Type: multipart/alternative;<br>
<x-tab>
</x-tab>boundary="----_=_NextPart_001_01C33139.69604059"<br>
</blockquote>
<blockquote type="cite" cite><font face="Verdana" size="-1">I was
wondering -- how hard would it be to re-create Sketchpad in Squeak?
Or maybe my question is really, can Squeak do everything that
Sketchpad could do?</font><br>
</blockquote>
<blockquote type="cite" cite><font face="Verdana" size="-1">Are there
functional specs or manual available somewhere that describe in detail
what Sketchpad could do? I've seen grainy photos of Sketchpad,
and read some descriptions of it by Alan and others, but that is about
all that Google has shown me so far.</font></blockquote>
<div><br></div>
<div><br></div>
<x-sigsep><pre>--
</pre></x-sigsep>
</body>
</html>