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∂22-DEC-75  0127	FTP:GLS at MIT-AI   
Date: 22 DEC 1975 0426-EST
From: GLS at MIT-AI
To: JRA at SU-AI

I would like very much to read a copy of your book.
If you are interested in a poem, might I suggest
TGQ;TREE POEM @ MIT-ML ?  Or maybe I will be inspired by reading
the book.  I've not done too much about GC lately,
but be it known that I and Sussman have been hacking
with a new LISP-like interpreter, worrying about
implementation and semantics.  You might try reading
GJS;SCHDOC MEMO @ MIT-AI (it is in XGP form -- the TJ6 source
is GJS;SCHDOC >).
-------

∂23-DEC-75  1117	FTP:GLS at MIT-AI   
Date: 23 DEC 1975 1415-EST
From: GLS at MIT-AI
To: jra at SU-AI

Okay, my address is:
	Guy L. Steele Jr.
	MIT Project MAC
	Room 834
	545 Technology Square
	Cambridge, Mass  02139
Thanks muchly for opportunity to see wonderful new lisp book.
		-- Guy
-------

∂30-DEC-75  0556	FTP:GLS at MIT-ML   
Date: 30 DEC 1975 0856-EST
From: GLS at MIT-ML
Subject: LISP MACHINE
To: JRA at SU-AI

WELL, GREENBLATT HAS BEEN OUT OF TOWN FOR A COUPLE OF WEEKS
FOR THE HOLIDAYS, AND BEFORE THAT HE HAS BEEN HACKING THE
CHESS MACHINE MOSTLY.  I HAVE SEEN THE LISP MACHINE PERFORM
BYTE DEPOSITS, ETC. (I.E. THE MICROCODE WORKS), BUT I'M
NOT SURE IF THE MAIN MEMORY HAS BEEN HOOKED UP YET.  ALSO IT
HAS NO PERIPHERALS RIGHT NOW -- IT HANGS OFF A PDP-11, WHICH
IN TURN IS INTERFACED TO MIT-AI PDP-10.
-------

∂01-JAN-76  0639	FTP:GLS at MIT-ML   
Date: 1 JAN 1976 0940-EST
From: GLS at MIT-ML
To: JRA at SU-AI

BOOK ARRIVED YESTERDAY IN FINE CONDITION.  I WILL GUARD IT
WITH MY LIFE FROM XEROX MACHINES.  IT IS INDEED ALREADY QUITE
BIG -- I WOULD SUGGEST THAT YOU PUT DATA BASES, ETC. IN VOLUME 2.
I'VE NOT READ MORE THAN A FEW PAGES; YOU'LL PROBABLY HEAR MORE
FROM ME AS I PROGRESS.  JUST GLANCING THROUGH IT THOUGH, IT LOOKS
LIKE THE BOOK I'VE BEEN WAITING FOR YEARS TO SEE.  HAVE A HAPPY
NEW YEAR.
			-- GUY
-------

∂19-JAN-76  1220	FTP:GLS at MIT-ML   
Date: 19 JAN 1976 1519-EST
From: GLS at MIT-ML
To: JRA at SU-AI

I HAVE BEEN SLOWLY BUT SURELY PLOWING THROUGH THE BOOK.
RIGHT NOW I'VE ABOUT FINISHED CHAPTER 2, BUT MY PACE SHOULD
ACCELERATE NOW THAT MID-JANUARY PWE EXAMS ARE OVER.
I THINK THE APPROACH IS INTERESTING, BUT THERE ARE SOME BUGS.
I'VE LOST YOUR MAILING ADDRESS, SO IF YOU'LL ARPA-MAIL IT
TO ME, I'LL MAIL YOU BACK THE PAGES CHAPTER BY CHAPTER,
WITH TYPOGRAPHICAL CORRECTIONS AND AMUSING COMMENTARY BY
YOURS TRULY.
BY THE WAY, MACRAKIS TELLS ME YOU'LL BE SENDING HIM A COPY?
(GOOD LUCK, HE WILL BITCH EVEN WORSE THAN I WILL.)
-------

∂12-FEB-76  0845	FTP:GLS at MIT-AI   
Date: 12 FEB 1976 1143-EST
From: GLS at MIT-AI
To: jra at SU-AI

Be not discouraged.  I intend fully to review the entire book.
As I said, I have hope that the last half will be much better.
I'm sorry if I seemed harsh in my letter.  I will be quiet busy
for the next couple of weeks, but I think I can certainly mail
you reviewed chapters at the rate of one every three or four weeks
at worst.  Would that be sufficiently fast for your purposes?
-------

∂12-FEB-76  0902	FTP:GLS at MIT-AI   
Date: 12 FEB 1976 1200-EST
From: GLS at MIT-AI
To: jra at SU-AI

Well, now that I have a better idea of your audience,
I can do a better job of reviewing, I guess.
Maybe what mislead me was the title:  "The Anatomy of LISP"
looks like it means a book about LISP.  Maybe you want
something like "Computer Science: a LISP Approach",
except that that sounds like a tired cliche.  "The Anatomy
of LISP" is a great title -- it's just that it's not
precisely what the book is about, in some sense.
But maybe I am picking nits.
I suppose that m-expressions are okay.  I still say they are
hard to read.  Maybe if you had a better font, and pretyy-printed them
better.  I hope the printers have a good font.  The major problems are
that the semicolons are italic, and would look better if vertaical;
and that the square brackets don't have enough space between them,
so they're hard to count.
While you may not want to use "top", I think it is still true that
one shouldn't confuse errors with non-termination.  I don't see
how coalesced sums can possibly hurt you.  Another way is to use
"super-bottom" and "super-top"; i.e., every domain has its own
bottom and top, and there is a special bottom below all other
bottoms, and similarly tops.  But it is very confusing
to say that bottom means "undefined", and later to say "[43 -> x; y]
isn't 'bottom' -- it's *really* undefined".
-------

∂15-Feb-77  0944	FTP:GLS at MIT-AI (Guy L. Steele, Jr. )	hot scoops
Date: 15 FEB 1977 1245-EST
Sender: GLS at MIT-AI
From: GLS at MIT-AI (Guy L. Steele, Jr. )
Subject: hot scoops
To: jra at SU-AI
CC: GLS at MIT-AI
Message-ID: <[MIT-AI].64856>

None out here, really.  I have been slogging along writing a few
short papers for conferences and working on thesis.  The LISP
machine is pretty much working, in that quite a bit of software
works to the point where more can be developed on it instead
of the simulator.

∂03-Mar-77  1603	FTP:GLS at MIT-AI (Guy L. Steele, Jr. )	Knight displays
Date: 3 MAR 1977 1904-EST
Sender: GLS at MIT-AI
From: GLS at MIT-AI (Guy L. Steele, Jr. )
Subject: Knight displays
To: jra at SU-AI
CC: GLS at MIT-AI
Message-ID: <[MIT-AI].70877>

Well, a Knight display terminal consists of a TV monitor and
a separate keyboard (made by Microswitch).  The TV gives something
like 450 by 380 raster (i forget exact figures); using a 6x12
character matrix, this gives 96 chars wide and 37 or so lines.
The TV screen is repetitively refreshed on a bit basis from
a memory.
There are far more terminals than can be used at once - they are cheap
enough to have one in every office, naturally.  There are
14 "video buffers" of 16K 16-bit words apiece (room for
expansion to 16 buffers).  There is a crossbar (the video switch)
which connects bit sources to bit sinks (16x32).  Currently
the only sources are the video buffers, and sinks include all
the terminals and a Tektronix copier.
The video buffers hang off a unibus interface on a PDP-11.
A register controls which one is accessible to the unibus
(the PDP-11 also has 12K of normal memory).  The PDP-11 in turn
hangs off the MIT-AI pdp-10 to pdp-11 inteface, which makes
PDP-11 memory addressable from the PDP-10.  In this way
a user program, after making a number of system calls, can
write directly into the bits of the TV screen:
the user memory refeence is mapped by the paging box to a magic
address in high memory (location 2,,xxxxxx); the 10-11 interface
maps it to the correct PDP-11; the unibus interface maps it
to the correct TV buffer; and voila!
The unibus interface for the buffers has an ALU inside of it
which is sometimes useful; it can do an IORM faster for you
than the PDP-10 can.
The kayboards are similar to Stanford keyboards,
but I think have a few more keys.  They generate 15 bits
(64 code-generating keys @ 6 bits, shift lock, and left/right
each of ctrl/meta/top/shift).  The PDP-11 immediately folds this to 12
bits (top,shift lock, shift, meta, ctrl, and 7 bits of ascii)
and passes it to the PDP-10.  User programs can read them
in 12-bit or 7-bit mode.  User programs that read 12 bits
conventionally fold them down to 9 bits (meta, ctrl, ascii)
though they don't have to.
that answerthe question?  if not, tk@ai himself can probably helpp more.
			-- Guy

∂01-Feb-78  1057	FTP:GLS at MIT-AI (Guy L. Steele, Jr.) 	last message   
Date: 1 FEB 1978 1356-EST
From: GLS at MIT-AI (Guy L. Steele, Jr.)
Subject: last message
To: JRA at SU-AI
CC: GLS at MIT-AI, (BUG LISPM) at MIT-AI


    please, please. i'd like to know how to get information about 
    lisp machine, perhaps including lisp source.
    			john

Sorry.  The best thing to do is contact the LISP Machine Group
(BUG-LISPM @ MIT-AI).  The LISP Machine code lives
on various directories such as LISPM, LISPM1, and LMDOC
at MIT-AI, but you will probably have a hard time wading around
in it without guidance from wizards.