Path: utzoo!attcan!uunet!husc6!bloom-beacon!gatech!hubcap!ian
From: ian@esl.UUCP (Ian Kaplan)
Newsgroups: comp.parallel
Subject: Re: Dataflow machines exist
Message-ID: <1946@hubcap.UUCP>
Date: 17 Jun 88 12:17:32 GMT
Sender: fpst@hubcap.UUCP
Lines: 45
Approved: parallel@hubcap.clemson.edu

In article <1919@hubcap.UUCP> mcvax!nikhefh.hep.nl!arthur@uunet.UU.NET (Arthur Veen) writes:
>Just to set the record straight: allthough the dataflow field is full of
>paper designs, a few machines have been built, tested and (to some extent)
>evaluated. 
[ text deleted ]
>Sigma-1 is probably operational by now. That leaves 10 or 11
>machines that have actually run programs. Of these the Image Pipelined
>processor uPD7281 from NEC is a static dataflow processing element on a
>chip that has been incorporated in several machines (of which I 
>have no details).
>Finally , work is going on here in The Netherlands on a
>commercial dataflow machine of which the first prototype is nearing
>completion. Keep a look-out for its announcement.
>The dataflow field is less fashionable (and less crowded) than it was 5 years 
>ago but certainly  not dead.

  The Japanese Sigma is indeed completed.  They have something like a
128 processor machine.  They also have some kind of data flow
compiler, but I have been unable to find any details.  I hope that the
Sigma group will have some papers in this years International
Conference on Parallel Processing.  Currently, the Japanese seem to be
the leaders in data flow research.

  As to the NEC uPD7281, it does indeed use data flow principles, but
it is difficult to build a system with a lot of processors, since the
chip was not designed for this.  Also, the chip does not have any
"hooks" for implementing anything like demand driven dataflow, which
means that it is not practical for implementing a general purpose data
flow machine.

  I hope that if any details on the Netherland machine become
available they will be posted on the net.  Data flow may not be dead,
but it sure seems to be in a deep sleep.  This sort of reminds me of a
Monte Python skit about a Parrot....  If anyone has details on the
Sigma machine, I would love to see those as well.

           Ian L. Kaplan
           ESL, Advanced Technology Systems
           M/S 302
           495 Java Dr.
           P.O. Box 3510
           Sunnyvale, CA 94088-3510

           ian@esl.COM
           esl!ian@ames.arc.nasa.gov