Path: utzoo!mnetor!uunet!husc6!mailrus!ames!ubvax!smegma!mdg From: mdg@smegma.UUCP (Marc de Groot) Newsgroups: comp.lang.forth Subject: Re: Novix chip with Computer Cowboys software by Calvin Moore Message-ID: <385@smegma.UUCP> Date: 9 May 88 07:49:09 GMT References: <17430@glacier.STANFORD.EDU> <460@ghidrah.tessi.UUCP> Reply-To: mdg@smegma.UUCP (Marc de Groot) Organization: A moving point in 4-space Lines: 73 In article <460@ghidrah.tessi.UUCP> bobl@ghidrah.UUCP (Bob Lewis) writes: >In article <17430@glacier.STANFORD.EDU> jbn@glacier.STANFORD.EDU (John B. Nagle) writes: >> >> I just saw the Novix chip running under the control of the silliest >>user interface I have ever encountered. This interface is Chuck Moore's personal research effort. Chuck (who I cannot really speak for) has some very particular ideas about Forth, being its in- ventor, and is not particularly concerned with popular acceptance of hid ideas, even within the Forth community. I would postulate that this is one reason his company is called Computer Cowboys; he is a "cowboy", an individualist. >> The Forth implementation lacks DO and LOOP. There's an absolutely >>hysterical bug: multiply only works for even multipliers. This is documented; >>the documentation claims that "most multipliers are even", you see. (Sigh) Whoever wrote this is no marketing person, and clearly did not understand or did not care that the remark would have a VERY negative effect on those who did not understand the background of the chip. The chip's development was stopped one iteration short of being totally debugged: the silicon for sale right now is buggy, and in my opinion should be taken as an indication of what this technology *might* do, someday, 'cuz what it's doing now is not very professional. >I suppose that in most cases one could use (forgive me if my FORTH is a >little rusty): > > : *SAFE 2* * 2/ ; > Yes, this works, but the top number on the stack is only a 15-bit signed integer. I suppose I am qualified to make some statements about the chip, being the author of SC-Forth, sold by Silicon Composers of Palo Alto. 1) The NC4000 has some truly unique, RISC-ish characteristics. There are many lessons to be learned from its design. 2) Like so many things about Forth, the NC4000 is an unprofessional presentation of some profound concepts about computer architecture. Many people see no further than the lack of polish. 3) The chip, at very least, proves that it is possible to construct a hardware Forth processor which is capable of very high power and speed. 4) This processor *is* usable for compute-bound applications (ray-tracing, etc) and is being used in obscure circles as a super-computer solution at relatively low cost. Heck, I like the thing. What do I like? 1) 16-bit processor, where clock speed in MHz = number of MIPS, up to 6 or 7 MIPS. 2) 4000 gates is all it took! 3) What other chip does a subroutine call in 1 clock tick? (The return happens in parallel with the last instruction in most routines.) 4) OK, the interrupt hardware is broken, but if it was bug-free, the interrupt latency would be 1 clock tick because the context is *already* saved on a stack! More next time. -- Marc de Groot (KG6KF) UUCP: {hplabs, sun, ucbvax}!amdcad!uport!smegma!mdg AMATEUR PACKET RADIO: KG6KF @ KB6IRS "Look, he's mounting a tape!" "Quick, throw cold water on him!"