bph@buengc.BU.EDU (Blair P. Houghton) (08/02/88)
While the topic of microprocessor chips is floating around, I'd like to ask Whatever happened to the Zilog Z80000? I remember getting a preliminary spec. for the thing, and it looked fairly decent; it could have competed with the M68000, TI32000, or the **86 series with ease. Anybody know why it isn't famous, like its ubiquitous-if-unrespected grandfather, the Z80? --Blair
spector@vx2.GBA.NYU.EDU (David HM Spector) (08/02/88)
As I recall (my memory may be faulty...) they had massive production problems
with the Z80000, and the chip was very expensive, and some intructions didn't
work, and.... it eventually just died a quit death...
_DHMS
-------------------------------------------------------------------------------
David HM Spector New York University
Senior Systems Programmer Graduate School of Business
Arpa: SPECTOR@GBA.NYU.EDU Academic Computing Center
UUCP:...!{allegra,rocky,harvard}!cmcl2!spector 90 Trinity Place, Rm C-4
HamRadio: N2BCA MCIMail: DSpector New York, New York 10006
AppleLink: D1161 CompuServe: 71260,1410 (212) 285-6080
"What computer puts out work like this?" "Hire us and we'll tell you."
XYZZYGLORPjbn@glacier.STANFORD.EDU (John B. Nagle) (08/02/88)
The Z80000 was supposed to be a follow-on to the Z8000, a modestly successful 16-bit micro very much like the PDP-11 in architecture. Unfortunately, the Z8000 had almost exactly the same limitations as the PDP-11 in terms of address space and organization of the memory management system. The architecture simply would not let a single process use more than 64K code and 64K data. This killed the product line. There were a number of UNIX boxes built using the Z8000, including some from Zilog, but it never really caught on. John Nagle
james@bigtex.uucp (James Van Artsdalen) (08/03/88)
In article <677@buengc.BU.EDU>, bph@buengc.UUCP (Blair P. Houghton) wrote: > While the topic of microprocessor chips is floating around, I'd like to ask > Whatever happened to the Zilog Z80000? > I remember getting a preliminary spec. for the thing, and it looked > fairly decent; it could have competed with the M68000, TI32000, or > the **86 series with ease. I'm not sure that the Z80000 ever worked. The Z8000 was as brain damaged as the the 8086 (segments with 16 bit limits) and died when it didn't get picked up by a major vendor like IBM. This didn't help the Z80000 any. Zilog never seems to have had much credibility with systems designers anyway. Another thing to consider is that Zilog never made any money - it was a money sink for its parent, which I think was Exxon. Zilog is apparently still in business, but I don't know who the current owner is or if they've abandoned the processor market entirely. -- James R. Van Artsdalen ...!ut-sally!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746
pf@diab.se (Per Fogelstr|m) (08/03/88)
In article <7650005@vx2.GBA.NYU.EDU> spector@vx2.GBA.NYU.EDU (David HM Spector) writes: >As I recall (my memory may be faulty...) they had massive production problems >with the Z80000, and the chip was very expensive, and some intructions didn't >work, and.... it eventually just died a quit death... > _DHMS >------------------------------------------------------------------------------- Would you belive it ! It's not "Dead". It has been repacked into something called Z320 (i'm not really shure about the name) and called the first micro for $1 a bit ($32 for a 32bit micro). The target market for this processor, as i understand , is the "Embedded controller market". Well Zilog is not the first :-).
cramer@optilink.UUCP (Clayton Cramer) (08/04/88)
In article <17599@glacier.STANFORD.EDU>, jbn@glacier.STANFORD.EDU (John B. Nagle) writes: > > The Z80000 was supposed to be a follow-on to the Z8000, a modestly > successful 16-bit micro very much like the PDP-11 in architecture. > Unfortunately, the Z8000 had almost exactly the same limitations as > the PDP-11 in terms of address space and organization of the memory > management system. The architecture simply would not let a single > process use more than 64K code and 64K data. This killed the product line. > There were a number of UNIX boxes built using the Z8000, including some > from Zilog, but it never really caught on. > > John Nagle The Z8000 consisted of two related processors: Z8002 and Z8001. The Z8002 was limited to 64K code and 64K data space -- but there is a little more to the story than that. The Z8000 consisted of a total of six address spaces: System Code, System Data, System Stack, Normal (application) Code, Normal Data, and Normal Stack. Each address space was 64K is size. While the Z8002 was still limited to 64K in each address space, it meant that your operating system could take 64K of code, 64K of data, and then a 64K stack, with no danger of any of them intruding on each other, and the application programs had their 64K of code, of data, and stack to play in. Not as elegant as a flat address space, or even the 8086 segmentation scheme, but as an alternative to a Z80, it was a giant improvement. The Z8001 supported a very clumsy memory segmentation scheme that enabled addressing a total of 128 separate 64K segments for each address space -- or 6 * 2^23 bits of address space. The Z8000 family was much more successful in Europe than in America, but there were applications for it, including (if memory serves me correctly) the F16 fire control system. The Z8000 had a very elegant instruction set (ignoring the memory addressing) for a microprocessor, in my opinion, much superior to the 68000. It had 16 general registers, each of which could be used for practically anything (major restriction being that 0 couldn't be used for indexing), unlike the 68000's division into D and A registers. The Z8000 was also very fast, when it came out in 1981-82. If it had appeared two years earlier, I think it likely that the 68000 would have suffered greatly by comparision. Clayton E. Cramer
ken@aiva.ed.ac.uk (Ken Johnson) (08/05/88)
In article <677@buengc.BU.EDU> bph@buengc.UUCP (Blair P. Houghton) writes
about `Mythical microprocessors'.
The first computer I ever used, in about 1970, was called the `Linc
Eight', a machine the size of a wardrobe with 4K of memory in real
ferrite core store and inch-wide Dec-tape. I imagined the name `Linc
Eight' (Linc being an abbreviation of Laboratory INstrument Computer) to
be the most recent in a line of successively improving models, starting
with the Linc One, the Linc Two and the Linc Three, through the Linc
Four, and the Linc Five, and ending up with the Linc Six, the Linc Seven
and the culmination of the dynasty, the Linc Eight.
Alas, the Linc Eight was a half-and-half mixture of two older machines:
the Linc for one, and the PDP-8 for two. So the Linc One, Two, Three
etc. never existed.
--
------------------------------------------------------------------------------
From: Ken Johnson (Half Man Half Bicycle)
Address: AI Applications Institute, The University, EDINBURGH
Phone: 031-225 4464 ext 212
Email: k.johnson@ed.ac.ukgillies@p.cs.uiuc.edu (08/06/88)
First, EXXON bought Zilog in the early 1980's (1982?), and proceeded
to kill it. Remember Exxon office systems, built from Z80 CPUs?
Zilog's glory days ended shortly thereafter. Xerox does this all the
time (kills thriving companies after purchasing them) (e.g. Shugart &
Diablo).
I heard that the (oriental) designer of the Z80 and Z8000 did most of
the design in his head. That is, he understood almost the entire CPU
and its layout in VLSI. I think he left from Zilog before the Z80,000
was complete. Had he stayed (to influence the Z80,000 design), the
chip might have been more successful.
Don Gillies, Dept. of Computer Science, University of Illinois
1304 W. Springfield, Urbana, Ill 61801
ARPA: gillies@cs.uiuc.edu UUCP: {uunet,ihnp4,harvard}!uiucdcs!gilliesroy@phri.UUCP (Roy Smith) (08/07/88)
ken@uk.ac.ed.aiva (Ken Johnson,E32 SB x212E) writes: > the Linc Eight was a half-and-half mixture of two older machines: the > Linc for one, and the PDP-8 for two. Didn't DEC once sell something called a MINC? As I remember, it was basicly an 11/23 in a funny roll-around chassis with some double-wide Q-bus slots designed to take analog I/O modules and the like. Came with all sorts of nifty peripherals like a card with a bank of 10-turn pots on it (anybody for /dev/trimpot?) -- Roy Smith, System Administrator Public Health Research Institute {allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net "The connector is the network"
mlinar@eve.usc.edu (Mitch Mlinar) (08/08/88)
In article <3423@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: > Didn't DEC once sell something called a MINC? As I remember, it >was basicly an 11/23 in a funny roll-around chassis with some double-wide >Q-bus slots designed to take analog I/O modules and the like. Came with >all sorts of nifty peripherals like a card with a bank of 10-turn pots >on it (anybody for /dev/trimpot?) That's right, Roy! We still got one floating around the lab; the wheels are a big plus since nobody wants it so it keeps getting pushed somewhere else. I bet that sucker has seen 10,000 miles on it during the last year... The MINC-11 is as you described; we had all kinds of A/D and some D/A attached to it. Turn pots were there for adjusting supply voltage and sensitivity for external equipment, clock rates, etc. Of course, it has DECs MINC BASIC to back it up - which was really quite good for I/O stuff. Our setup only had two 8" DS floppy drives. I am not sure how much storage we had, but we could stuff all the MINC BASIC and their Fortran one on disk. The libraries manipulated all the h/w quite well, but the stuff ran S-L-O-W. With the proliferation of the IBM-PC and I/O cards for it, this EXPENSIVE hulk became obsolete... -Mitch
mlinar@eve.usc.edu (Mitch Mlinar) (08/08/88)
In article <79700005@p.cs.uiuc.edu> gillies@p.cs.uiuc.edu writes: > >I heard that the (oriental) designer of the Z80 and Z8000 did most of >the design in his head. That is, he understood almost the entire CPU >and its layout in VLSI. I think he left from Zilog before the Z80,000 >was complete. Had he stayed (to influence the Z80,000 design), the >chip might have been more successful. > The name of the designer escapes me right now, but I believe he was from India. Also, he laid out the Z80 and Z8000 primarily using RANDOM LOGIC. He was *very* good at it, but also realized that regular structures like PLAs, etc. would be required for the next generation. The Z8000 took a *lot* of man-months in comparison to other CPUs of that time due to the random logic, but was faster because of it. To this day, I know of no synthesis tools for CPUs which can handle timing generators (the method used in the Z80 and Z8000). Current chips are all micro/nanocontrollers and/or PLA table driven. Timing generators ARE faster for a comparable size design, but the complexity versus speed gain is just not worth it. Then, there is the issue of verification. Ugh! -Mitch
markz@ssc.UUCP (Mark Zenier) (08/09/88)
In article <11419@oberon.USC.EDU>, mlinar@eve.usc.edu (Mitch Mlinar) writes: > In article <79700005@p.cs.uiuc.edu> gillies@p.cs.uiuc.edu writes: > > > >I heard that the (oriental) designer of the Z80 and Z8000 did most of > >the design in his head. That is, he understood almost the entire CPU > >and its layout in VLSI. I think he left from Zilog before the Z80,000 > >was complete. Had he stayed (to influence the Z80,000 design), the > >chip might have been more successful. > > | | The name of the designer escapes me right now, but I believe he was from | India. Also, he laid out the Z80 and Z8000 primarily using RANDOM LOGIC. He | was *very* good at it, but also realized that regular structures like PLAs, Not good enough, I wasted a week chasing down the fact that some early revisions of the z8002 would confuse the user stack pointer register with the system stack pointer register if the timing clock was within a 1 nanosecond window, when the moon was in the right phase, and the temperature was just wrong. Just what you need in an embedded controller. | etc. would be required for the next generation. The Z8000 took a *lot* of | man-months in comparison to other CPUs of that time due to the random logic, | but was faster because of it. | | To this day, I know of no synthesis tools for CPUs which can handle timing | generators (the method used in the Z80 and Z8000). Current chips are all | micro/nanocontrollers and/or PLA table driven. Timing generators ARE faster | for a comparable size design, but the complexity versus speed gain is just | not worth it. Then, there is the issue of verification. Ugh! | | -Mitch They (in '84) only got the z8000s up to 12 Mhz, while the 68000 got up to 16. Even though the z8000s only needed 3 cycles per memory reference compared to the 68000's 4 cycles, their slow silicon didn't cut it. Another problem with the z8000s was it took two years from first announcement until it was real. The 68000 was announced a year later, but they both were available at the same time. Mark Zenier uunet!pilchuck!ssc!markz LOGGERMIST CROTEHAVEN