Path: utzoo!attcan!uunet!lll-winken!ames!sun-barr!rutgers!aramis.rutgers.edu!bearcat.rutgers.edu!lou From: lou@bearcat.rutgers.edu (Lou Steinberg) Newsgroups: comp.lang.lisp Subject: Re: Unix Lisp Environments (why the slow evolution) Message-ID: Date: 12 May 89 14:34:47 GMT References: <1989May11.013529.11949@cs.rochester.edu> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 46 In all this discussion, I still haven't seen anyone mention the main reason (IMHO) that Unix workstations are usually preferable to lisp machines. It has nothing to do with the intrinsic merit of the machine architecture or the software system. Rather, Unix boxes are better because "everyone has one", both in the sense that large numbers of people own them and in the sense that large numbers of companies sell them. Here at Rutgers, for instance, we have two symbolics machines and probably over a hundred Suns. The symbolics machines may intrinsically be easier to support, but I simply can't tell. Any possible intrinsic advantage of symbolics is swamped by the fact that there are so many people around here who can answer questions about the suns, and write or collect software for the suns, and no one who is a real symbolics wizard. A similar argument applies to the hardware architecture. Motorola sells so many 68xxx chips it can afford a Whole Lot of engineers to tweak every last nanosecond out of every last transistor. Symbolics simply can't afford that degree of low-level optimization, and it has turned out that the advantage of a specialized architecture just doesn't make up for the disadvantage of low volume and hence less optimization. With the advent of sparc (sun-4) and other risc architectures, the advantages of symbolics' specialized micro-code have gotten even less, since with risc the machine language is essentially micro-code, and the instruction cache fills the role of the micro-code memory. (And sparc was in fact designed partly with lisp in mind.) Finally, the fact that lots of companies sell Unix boxes means that Sun has to be competitive in price, performance, and service. If they try to charge too much I can always go elsewhere. With lisp machines you have much less choice. (Otherwise symbolics could not charge what it does.) Let me end by emphasizing that these considerations are not always decisive for everyone - I've seen the Allegro Composer environment from Franz that was mentioned here, and I agree that the unix-based programming environments are rapidly closing the gap, but they aren't fully there yet. However, for most situations, I think the issues I've mentioned here do mean unix-based lisps are preferable. -- Lou Steinberg uucp: {pretty much any major site}!rutgers!aramis.rutgers.edu!lou arpa: lou@aramis.rutgers.edu