Chuck Guzis wrote:
Remember "Madman Muntz"?
:)
Ahh - there's a flood of bad memories. What a bunch of utter crap he turned
out. Two or three functions on one vacuum tube. Remove parts one at a time
until the set doesn't work. Then add the last one back in. Sheet metal
>from tin cans. High voltage wires with poor shielding.
You've brought back a lot of memories, but not pleasant ones. He was one of
the true characters to come out of our field.
Billy
> -----Original Message-----
> On Behalf Of Chris M
> Sent: Monday, December 11, 2006 3:33 PM
>
> I remember there being a product by AT & T which was
> capable of manipulationg "microdots" (micropels?,
> thereby creating screen resolutions much greater then
> was common in those days. It was a boardset and may
> have been built around the 34010 (not sure about that
> though - I think the product was called Targa, and I
> could have confused Targa and TIGA).
I remeber the AT&T TARGA. Output was to a RGB monitor. Input via tablet with a puck and a wand. They had it running on a Wyse PC/286. I wrote a converter to the Amiga IFF and PC GIF, but I can't find the source any more.
I worked at the video lab for the County College of Morris (in New Jersey) back in 90-92. They also had some SGI stuff and some film printers for the PC. All networked via ethernet. Pretty advanced for a community college.
Kelly
William Donzelli wrote:
> I think a bigger factor here was the consistentcy of switching time. All
of
> Seymour's design are incredibly tight on switching time. He liked to line
> up signals so they would reach the next gate at the same time without
> requiring a clock. Having only one gate switch time would ease design. In
> all of his designs that I have worked on, he made flip flops and adders
out
> of individual gates. Again to have exact control of the switching time.
This makes no sense. In every ECL family I have seen, when gates are
assembled onto one die to make a logic function, the sum is always
faster (often by a good amount) than if the same design was done using
individual gates. Even if the individual gates are hand picked for
speed, the complete logic function will be faster. And there is
nothing to keep anyone from hand picking the complex logic functions
for speed, as well.
----------------------------------
Seymour Cray did not like to use clocks. For example, his designs call for
all the outputs of an adder to be perfectly aligned. He also did not like
carry propagation, and wanted all the carrys out at the same time as the
data. I've never seen LSI that could achieve this on 64 bit operands.
Compare the speeds of some of his arithemetic units, especially the parallel
multipliers, to LSI contemporary to his design.
---------------------------------
There is also the speed gain of having more computing logic per board.
For example in an individual gate design, the extra 2 inches of
microstrip traces on the board, plus all the extras involved with
getting the signal on and off each chip package, can add up to a
significant part of a propagation delay of a gate. And, with more
complex boards, the machine could get smaller, with a speed increase
gained there as well, as the backplane (backnest?) would get smaller.
----------------------------------
But the switching time of even one gate is longer than the 2 inches of foil.
His designs actually use the layout to deskew circuits. And he was big on
cordwood packaging to eliminate the length of signal runs. Signals going off
a module in all of his designs, are carefully timed and include the foil
length and the board interconnects, be they wire or coaxial. All of what
you say was true and carefully considered during design. Even where the
modules were placed in a chassis was taken into account. I remember one
chassis was completely re-laid out, to put the carry circuits in the center
of the chassis because they had the longest propgation paths.
-----------------------------------------------
> And to eliminate any un-necessary logic. There are no unused gates in any
> of his computers.
This is certainly a valid reason, and for some of his later designs I
can see where an ECL ALU (100181, for example) may have too many extra
things. Ok, perhaps a bad example, as I do not think Cray designs use
ALUs, or 100K, but it is what springs to mind. But, with something
like an and-or-invert gate, or even a multiplexer or demultiplexor,
the off the shelf designs are basically minimized.
I know the Cray-1s ECL was something like MECL III or 100K, and
certainly whoever the chip maker was could have supplied some basic
logic functions beyond a gate or two. I think the extra effort to use
them would have been minimal, with a great payoff.
---------------------------------
When he left CDC, he looked at commercial logic families. And I believe he
did do a design with MECL III. CDC proper moved on to MECL 10K for the
Cyber 170s and MECL 100K for the STARs and ETA systems. Some CDC designs
also used proprietory logic designs. But by then commercial logic suppliers
were able to do a better job than in-house designers could and they were
cheaper. Most of the in-house foundries were sold. CDC's was, and so was
DEC's and Data General's. IBM moved on to be the power house foundry it is
today. Makes you wonder who was right.
Meanwhile, Seymour moved into more exotic logic trying to get more speed. I
think he was working on a weird gallium-arsenide wafer scale design at the
time of his death.
At the time of the 6600, 7600 and Cray 1, there was no commercial family
that could equal the speed of the Cray designs. Some came along (10K/100K)
but they were real power hogs. Every gate had complimentary outputs. Every
signal had to be terminated. The heat generated was so great that every IC
had a heat sink under it, and the heat sink went to a freon cooled cold
plate.
I spent 4 year designing with MECL 10K. The experience was enough to
convince to get out of design and go back to the field. It was a miserable
family to work with. And I can assure you that there was skew on the
outputs of any of the LSI blocks, but really bad on the 10181. Even with
the special carry circuits, it took weeks of wire tuning to get the 96 bit
floating point adder to work.
We used to go back to the source (Seymour's design in the 7600) and marvel
at it. 5 years after he designed it using transistors, we were still trying
to equal his performance with MECL.
-------------------------------
> Miserable servicing? As someone who spent literally years tuning wires in
> Seymour's designs, I have to agree. His machines were very demanding to
> impossible to maintain. Just before it died, I spent a few hours on the
> 8600. None of us on that machine believed it could be maintained! And
the
> math models all gave the MTBF as a negative number!
I once heard that one of the big boxes in a computer room that hosted
a Cray would have a fancy tag like "Disk Control" or something, but
that was actually where the field engineer lived.
---------------------------------
On my last field site, my office was called "Spares."
--------------------------------------
Billy
>Silicone is pretty mushy stuff. I wonder if a polyurethane elastomer such
as Lexel might work a bit better?
>I use it for caulking around water and it's very sticky and sets to a
fairly firm texture.
>Cheers,
>Chuck
Oh, it's 'mushy'; used it to feed very fine paper w/o deforming it. It gets
a bit of paper dust on it and feeds very nicely. It doesn't work for a
pinch-pickup. I had access to fun industrial stuff in the long ago, but
I've since used a number of 3M, Loctite silicon/poly/ure electronic
encapsulants and consumer/commercial sealants (RTV and heat). I am sure
there is stuff that takes to high density and speed better, but my expertise
in this area is finite.
Cheer, jp
Cottonwood BBS is back online and operational!
After much trial and error, I've got all the right
pieces put together... So dust off your old modem,
and give Cottonwood BBS a call. It's presently the
only known Commodore dial-up BBS in existence!
I apologize to anyone who tried to call before... The
VoIP line I tried to use didn't work out... So I'm
back with a new number, a regular phone line, and NO
line noise!
Call now at +1 (951)242-3593
For detailed information on the BBS, and tips on
connecting, check out the Cottonwood BBS informational
website:
http://www.wiskow.hpg.ig.com.br/index.htm
-Andrew
aka Balzabaar (SysOp)
_______________________________________________________
Voc? quer respostas para suas perguntas? Ou voc? sabe muito e quer compartilhar seu conhecimento? Experimente o Yahoo! Respostas !
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Message was sent through the cbm-hackers mailing list
It's condition is unknown. It is taken out from a external SCSI case, and
the HD from the same case works. The face panel is lost, but other parts
look good. If you want it, you pay actual shipping from Ohio, US. Otherwise
I will dispose it to the city computer recycling program (not to reuse, but
to recycle the metal and plastic I guess).
vax, 9000
William Donzelli wrote:
Adding just ten more chip types will not significantly increase
manufacturing overhead. How many parts total were on the Cray-1 BOM?
10,000? 20,000? making it 10,010 or 20,010 is not going to strain the
inventory folks.
Also, by adding just ten more chip type, the total number of chips in
the system will have gone down - perhaps by ten percent. That will
greatly increase yield. Back in those hand-placed hand-soldered
surface mount days, board errors were far more likely to be bad solder
joints (using that old fashioned solder! horrors!) than misplaced
parts.
One of the Cray-1s faults was the somewhat miserable servicing
requirements, and the crummy downtime that forced it. Fewer parts
would have increased uptime (although many of the issues with the
machines were not chip related).
--
Will
--------------------------
I think a bigger factor here was the consistentcy of switching time. All of
Seymour's design are incredibly tight on switching time. He liked to line
up signals so they would reach the next gate at the same time without
requiring a clock. Having only one gate switch time would ease design. In
all of his designs that I have worked on, he made flip flops and adders out
of individual gates. Again to have exact control of the switching time.
And to eliminate any un-necessary logic. There are no unused gates in any
of his computers.
So I don't think inventory count was a factor. It was just his design
phiilosophy - minimum logic, exact timing. There is a great book on this:
"Design of a Computer: 6600". Al has it on his site; well worth downloading
and reading.
Miserable servicing? As someone who spent literally years tuning wires in
Seymour's designs, I have to agree. His machines were very demanding to
impossible to maintain. Just before it died, I spent a few hours on the
8600. None of us on that machine believed it could be maintained! And the
math models all gave the MTBF as a negative number!
Billy
HI,
I saw your post about, what ever happened to John Bell. We were friends in
high school, but I lost touch with him.
Yesterday I learned he passed away. He is listed as deceased on our high
school web site.
Do you know any other information about John?
Thanks,
Wayne
http://classreport.org/main/classdirectory.asp?dname=/usa/ca/san_mateo/smhs…
The John Bell 6502 board used to be advertised in the back pages of pre-1980
Byte magazines, along with a selection of other JB cards. I seem to recall
the 6502 card was minimal-chip system essentially aimed at "embedded
processor" type applications. So I don't think it came with a preprogrammed
EPROM; you were expected to develop your own firmware for it. They had
another bare board for a video display terminal based on an Intel 8085
(basically an implementation of the circuit in an Intel application note)
and they also sold some low-cost interface cards for Apple II parallel
interfacing using the 6522 VIA chips that were then popular in Commodore
Pets. I remember building a couple of those JB interfaces for lab
experiments. I wonder who "John Bell" was and whatever happened to him?
Arlen Michaels
Apologize in that I found out the system was not an HP 3000, and I
raised expectation of several list members about a system.
The good news is that it is a nice HP 9000 900, which is nice and fast
and has a good copy of HP/UX loaded, and will be visiting my house on a
permanent basis when I get back after the new year.
I have several of the visualize hp 9000's if anyone is into those, and
wants some. I won't discard them but would be willing to share them if
someone wants to come get them.
Jim
Anyone out there with a 800 BPI magtape drive that could read
some RSTS/E DecWord install tapes? Prefer a USA address,
due to shipping costs. Would like to make these images
available, but don't really want to spend $100 in shipping
costs. (5 tapes, about 6 lbs, from 83401)
