Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!encore!cloud9!cme
From: cme@cloud9.Stratus.COM (Carl Ellison)
Newsgroups: comp.graphics
Subject: Re: PS300 Function Networks
Message-ID: <4751@cloud9.Stratus.COM>
Date: 10 Apr 89 15:50:38 GMT
References: <7710@batcomputer.tn.cornell.edu>
Organization: Stratus Computer, Inc., Marlboro, MA
Lines: 31

In article <7710@batcomputer.tn.cornell.edu>, garry@batcomputer.tn.cornell.edu (Garry Wiegand as guest) writes:
> (For those who don't know: a function network is a directed graph
> of arithmetic functions. Data flows in one end, for example from a
> mouse, follows the connections, is transformed in arbitrary ways, 
> and flows out the other end, for example to affect a screen display. 
> The data flow happens *continuously*.  (Carl, did I say it right?))

Yes, that's an excellent short description.

I'd add only that the graph of arithmetic functions was built by the user
(or user's programmer) to fit the application and that nearly every
element in the hierarchical display data structure doubled as a function --
could be connected up as a data sinks in these graphs, so that the
display structure became part of the function net graph.  The values
received by display structure nodes were used as rotations, scales,
ink vectors, rubber band vectors, ..., depending on the type of display node.



Almost by accident, by the way, we discovered that the function nets provided
a good junction box for communications.  There was one PS300 in our lab
which was connected to both a VAX and an IBM mainframe.  Those two computers
couldn't talk together -- so one of our developers typed in a 2 connection
function network and, within a few minutes, the two hosts were
transferring files -- at 56Kb -- allowing the developer to use the VAX
for editing his IBM subroutine package -- a case of a painful editor
being the mother of invention.  He would probably never have tried it
otherwise.

--Carl Ellison                      UUCP::  cme@cloud9.Stratus.COM
SNail:: Stratus Computer; 55 Fairbanks Blvd.; Marlborough MA 01752
Disclaimer::  (of course)