Maclisp problems on Twenex.

[RMS at MIT-AI (Richard M. Stallman)]

I think that you have wrongly attributed the causes of some of the
problems you have encountered with Maclisp.  Let me explain.

    Because the proliferation doesn't seem to be taking the need for
    upward-compatibility very seriously.  I'd love to have some of the new
    features, if I did not have to live in 545 Tech Square to use them.  
You can SUPDUP to a Lisp machine from AI or MC and get a read-eval-print
loop.  (Have someone put a note on the console saying that the
machine is being used remotely.)  Incompatibilities between the Lisp
machine and Maclisp are few, and most are due to fundamental things.
However, most of what is new on the Lisp machine has to do with
the bit map display.  How can you ask to be able to use that
over the Arpanet?
			       ...  Consider: my LET macro has been superceded,
Should progress cease?  Isn't it a good thing that LET is now part of
the language, for everyone, and not just something that a few users
add on?
    ALLFILES does not work on 20X
The original code for ALLFILES on ITS is no use on 20X.  It isn't
a failure of compatibility; it is just unfinished business.  Finishing
such business mainly takes effort, which must come from hackers.
These things were done for Interlisp by people who expected to use
them.  Are you asking for them to be done for you by MIT people
(ITS users) who will never get any use from them?  The people who
ought to pitch in and do it are the 20X users.
				 , LEDIT does not work on 20X, 
This is the same as with ALLFILES, except that it
isn't even part of Maclisp; just something a user happened to write.
As it happens, a user has written a Twenex LEDIT and I will be
distributing it if I can get him to give it to me.
							       (TYO 27.) does
    not work on 20X
This is a difference between 20X and ITS, not between versions of
Maclisp.  If there were an ITS Interlisp it would probably have the
same difference from 20X Interlisp.  I suppose someone might try to
make Maclisp compensate for this difference; but if that were done, it
might possibly offend other 20X people by making Maclisp behave
differently from other 20X programs.  It needs to be thought about.

It's not that these problems aren't real problems for a user of 20X
Maclisp.  But I question whether the problems can be traced to
anything about Maclisp vs Interlisp, or to Maclisp vs LM Lisp vs NIL.