vix@ubvax.UUCP (Paul Vixie) (09/04/87)
A few months back, someone posted an article to comp.arch listing the phone number of a NEC sales department where one could request information on the NEC V60/V70 processors. I Called, gave my name and address to the very non- technical person who answered the phone, then shortly, forgot all about it. Yesterday, UPS delivered a medium-sized box to my door; it was the V60/V70 User's Manual, plus some data sheets, and a big white binder to hold all of it. The stuff is all labelled "Preliminary Information", and the manual is dated November, 1986. This manual actually covers the V60; the V70 is present only in data-sheet form, but is supposed to be architecturally identical to the V60. I want to share some impressions, maybe start some discussions, perhaps learn of existing machines using th[is|ese] chip[s]. I do not work for, represent, or have anything to do with NEC other than having received these manuals; also, these are personal opinions and do not have anything to do with Ungermann-Bass, whose machine I am posting this from. The V60 is a very vax-ish arch, with a V20/V30 emulation mode (which, if you recall, means it can run Intel 8086/8088 software). [Note: 8086/8088 and the word "Intel" are probably trademarks of Intel Corp, whose full name I do not remember and who, like NEC and UB, I do not represent here.] The chip has 32 general-purpose registers, four execution levels, four AST modes (AST = asynchronous system trap, a la VAX/VMS, (tm) Digital Equip, etc), three-level VM paging, hardwired 4KB pages, 16MB max real memory addressing (4GB virtual, per virtual address space), lots of addressing modes (including 'bit' addressing of bit strings up to 4 gigbits long, or bit fields of up to 32 bits, either can be on aribtrary bit boundary). The V70 is the same chip, but with a 32-bit address bus, and therefore a maximum real memory of 4GB. The part numbers of these chips are "uPD706xx" where xx=16 for the V60 and xx=32 for the V70. Both chips run at "up to" 20MHz, currently. This thing is very, very CISC. It's more like a VAX than the VAX is... It doesn't have a 'POLYx' instruction, but it has ANDNBS, for "AND Complemented Bit String"... :-)... It has more or less all the addressing modes that the VAX has. Comparisons ----------- I have not used any system containing this chip, and I don't know if they are even shipping. Therefore, and comparison between the V60/V70 and anything else has to be taken with a few Kg of NaCl. In terms of overall elegance, I prefer this chip to the National 32016 and 32032. I have not seen the NS32332 or 32532, so I can't comment on those... I'm very fond of the Fairchild Clipper, but since the Clipper purports to be a RISC machine, it doesn't make sense to compare it to the V60/V70. [Note: Fairchild and Clipper are very probably trademarks of Fairchild, Shlumberger, or National Semiconductor, depending on the state of the Fairchild-National deal by the time you read this]. I think this machine has more goodies to it than the VAX has. Not that I can think of any good reason to have 32 registers instead of 16 (which is what the VAX has); however, most of what the VAX arch has, the V60/V70 seems to have more of. Especially useful to the V60 in this comparison, is the ability to run 8086 code without coprocessor boards... I have a generally low opinion of the Intel 4004/8008/808[05678]/80[123]86 family; this is mostly because I do not like load/store architechtures. There are other reasons, available upon request... The 80386 has finally added paging, which was my major complain against its predecessors; it has a "virtual 8086" mode, which made "DOSMerge" (doubtlessly someone's (tm), but other than Microport I don't know whose...) a possibility, which makes it possible to run 8086 code in a UNIX environment, which is useful if inelegant. The V60/V70 has its V20/V30 emulation mode, which matches the 386's "Virtual 8086 mode"; once I cancel these two out, the V60/V70 with its addressing modes and GP registers and the like wins clearly. Summary of Disclaimers ---------------------- If I left your favorite CPU out, send me some mail or compare them yourself! If I mentioned any trademarks without giving credit, I apologize. If you've gotten this far without fully believing that I represent only myself, there's nothing more I can do. Summary of V60/V70 ------------------ I like CISC. (I also like RISC.) Of the CISC machines I've heard of, the V60/V70 stands out as about the most elegant and neat and nifty of the lot.. I would very much like to see a NUBus (tm of Texas Instruments, I'll bet) machine with a V70 at its heart, running a System-Vr3 UNIX (tm of AT&T) OS with TCP/IP (tm of DOD?) in done Streams (AT&T again), and something like DOSMerge (tm of ???)... If anyone knows of ANY machine based on a V70 and available in this country, please send me mail about it. If anyone wants to build and sell one, I'm availabvle for software consulting :-) :-)... -- Paul Vixie Consultant Work: 408-562-7798 vix@ubvax.ub.com Ungermann-Bass Home: 415-647-7023 ames!pyramid!ubvax!vix Santa Clara, CA <<I do not speak for Ungermann-Bass>>
tim@amdcad.AMD.COM (Tim Olson) (09/04/87)
I also received the "big white box" (padded with shredded documents, by the way!) with the V60/V70 Manual. One major thing I noted was the conspicuous absence of instruction cycle times; the entire column is blank.... -- Tim Olson Advanced Micro Devices (tim@amdcad.amd.com)