Make LispM code FREE (fwd)

Kragen kragen@pobox.com
Tue, 31 Mar 1998 22:48:35 -0500 (EST)


On Wed, 1 Apr 1998, Chris Bitmead wrote:
> >     Yeah, why create from scratch when there is a load of code out there
> > waiting to be pulled in or learned from.....?
> 
> Well, I don't know if it is comparable, but have you ever
> compared the source code to PDP-11 UNIX compared to, well say
> Linux? 

I've read bits of both, but only compared them cursorily.

> The PDP-11 version makes interesting reading, but not a
> single line of code is worth saving. 

I doubt that.  In fact, many lines of code are identical in both.  errno.h,
for instance.

> In fact I'd say very little
> of the design is probably worth saving either.

Actually, Linux's basic design is very much the same as PDP-11 UNIX.
The whole filesystem design, multitasking design, etc., is almost
identically replicated in Linux.  Linux's design is *much* more similar
to V6 UNIX than to MVS, VMS, Windows NT, Amoeba, Mach, Sprite, KeyKOS,
etc.

Memory management's very different, though.

> The MIT lisp code would surely be interesting, but I really doubt
> it is going to be much more than a curiousity rather than the
> base for a new LispOS.

You may be right.  But listening to Rainer and others talking about
inspectors and listeners, I'm hearing concepts that never before
entered my mind, and I expect that many of them will be implemented in
the MIT Lisp machine code.

Kragen