Re: DECstation 15e ?

[Scott_Fahlman@SEF-PMAX.SLISP.CS.CMU.EDU]

Paul,

Rob passed your query on to me.  I am the CMU Common Lisp project leader
and handle the policy questions.

We've looked at a port to the current bsd-based Ultrix, but it looks very
hard to us because this Ultrix (the version we have here, anyway) doesn't
support memory mapping of arbitrary files.  This means that we would have
to completely reorganize how the CMU CL is laid out in memory, and that
would take several months of hard work.  We understand that the next
release of Ultrix will be OSF-compliant, which would allow us to avoid all
this work and use our current memory model.  So, despite the size of the
"market", we have decided that it would be a waste of our time to port CMU
CL to the current bsd Ultrix in its last days.

By the way, we're not discriminating against Digital and in favor of Sun.
This problem didn't come up with our SunOS port because SunOS has a true
mmap.

We do want to port to the new OSF/Ultrix, whenever it is released.  The
donation of a machine at that point could make a big difference.  The issue
is not getting the port done -- the Mach version of CMU CL might work, more
or less, without any major changes.  But thre are sure to be small
compatibility problems, and we need a support machine running Ultrix if we
are to deal with them in a timely manner.  At present, our group only has
two Decstations for Lisp development, both running Mach, and we can't
afford to sacrifice either of them for Ultrix support.

-- Scott
===========================================================================
Scott E. Fahlman
School of Computer Science
Carnegie Mellon University
5000 Forbes Avenue
Pittsburgh, PA 15213

Internet: sef+@cs.cmu.edu