Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!hal!nic.MR.NET!thor.acc.stolaf.edu!mike From: mike@thor.acc.stolaf.edu (Mike Haertel) Newsgroups: comp.arch Subject: Re: Lisp Chips Message-ID: <5200@thor.acc.stolaf.edu> Date: 1 Sep 89 18:15:05 GMT References: <70663@yale-celray.yale.UUCP> <1989Aug26.232710.27174@utzoo.uucp> <1989Aug30.152155.9613@mentor.com> <26595@winchester.mips.COM> <240@ssp1.idca.tds.philips.nl> Reply-To: mike@thor.stolaf.edu () Organization: St. Olaf College, Northfield, MN Lines: 21 In article <240@ssp1.idca.tds.philips.nl> dolf@idca.tds.PHILIPS.nl (Dolf Grunbauer) writes: >Just a short I-just-want-to-know question: is it true that the DEC-10 systems >processors were designed for an efficient Lisp implementation, and was it >efficient ? (I once heard someone state that these processors were made with >two high-level languages as aims, one of which was Lisp, and the other I forgot >(I guess it must be FORTRAN isn't it ?)). I don't know if Lisp support was a design goal of the PDP-10 architecture, but I do know that ITS (the Incompatible Timesharing System) included custom microcode for the KL- and KS-10 processors (I believe the main effort in porting ITS to a new processor was the microcode). It added several instructions, including a few needed by MACLISP. I don't recall exactly; it's been a while since I read the microcode, but I think the new instructions included something special for Deutsch-Schorr-Waite garbage collection (probably something like atomic test-and-mark with conditional branch), and perhaps also something for tagged arithmetic. I may be totally off the mark here, but this is what I seem to recall. -- Mike Haertel ``There's nothing remarkable about it. All one has to do is hit the right keys at the right time and the instrument plays itself.'' -- J. S. Bach