[comp.arch] Josephson Junction processors

rvk@twitch.UUCP ( Bob Kline) (03/16/89)

the processor mentioned built of Josephson Junction devices
is claimed to run at something like 250 MIPs.


yes, perseverence seems to be the Japanese winning strategy
all right.  people in the U.S. once had a reputation for
this also.  about the time IBM got out of JJ research, one
investigator was able to take some of the technology and 
start a small company - Hypress I believe.  the first offering
was a 70 GHz sampling scope.  I'm told the company has recently
introduced a 28 GHz broadband scope for rf work, and is eyeing
computers.

the approach initially used (maybe still used) to cool the
chips to necessary temperatures was to simply drip liqued
(i.e., liquid) helium on one corner.  strightforward, and it
works.

perhaps a longer term worry is that the Japanese devices have
tens of thousands of devices on them, so larger systems can
apparently be built and adequately cooled.  what breakthroughs and
techniques were uncovered that IBM missed I don't know, but it
is believable that the Japanese now possess a viable technology
that our biggest and best couldn't see through.

henry@utzoo.uucp (Henry Spencer) (03/17/89)

In article <1196@twitch.UUCP> rvk@twitch.UUCP ( Bob Kline) writes:
>...perhaps a longer term worry is that the Japanese devices have
>tens of thousands of devices on them, so larger systems can
>apparently be built and adequately cooled.  what breakthroughs and
>techniques were uncovered that IBM missed I don't know, but it
>is believable that the Japanese now possess a viable technology
>that our biggest and best couldn't see through.

Let's not get too excited about this just yet.  IBM had some impressive
experimental hardware too.  IBM did *not* abandon its big JJ project
because it couldn't be made to work in the lab, they abandoned it because
they felt it couldn't be made to work well enough to be a commercial
success.  It is still possible that they were right.
-- 
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
passport and visa, comrade?    | uunet!attcan!utzoo!henry henry@zoo.toronto.edu

njs@scifi.UUCP (Nicholas J. Simicich) (03/22/89)

As long as superconductivity required liquid helium for cooling, one
had to worry about what producing large commercial quantities of this
sort of equipment would do to the cost and availability of liquid
helium.  

I personally hope that some fallout from the new high temperature
superconductivity discoveries will be applicable.

Speaking for myself, of course.


-- 
Nick Simicich --- uunet!bywater!scifi!njs --- njs@ibm.com (Internet)