Path: utzoo!attcan!uunet!jvc!jonathan
From: jonathan@jvc.UUCP (Jonathan Hue)
Newsgroups: comp.periphs
Subject: connecting a graphics tablet to a UNIX box
Message-ID: <471@jvc.UUCP>
Date: 18 Mar 89 00:31:40 GMT
Organization: JVC Laboratory of America
Lines: 24


Has anyone ever hooked up a graphics tablet to a UNIX workstation.  For some
strange reason, my boss wants me to connect a Summagraphics and
a Numonics tablet to a Sun workstation.  The problem is that I don't want
the workstation to get hammered by interrupts from a continuous stream of
tablet data.  I can put the tablet into increment mode, where it only sends
data when the puck is moved, or in point-switch mode, where it only
sends data when a button is down.  What I want is for it to send data only
when the puck moves or a button is pressed (like the mouse).  Unfortunately,
the tablets don't support this mode.

I modified my Sun X server so it uses the tablet in increment mode instead of
the mouse.  It works fine, but it won't see a button transition unless you move
the puck a tiny bit at the same time.  If I can't get some custom firmware from
the tablet vendors which makes the tablet work the way I want, I might build
a little "black box" which takes in continuous tablet data, and only sends
tablet data to the host when the puck moves or a button is pressed/released
(using some cheap microcontroller with built-in serial ports, and a tiny
bit of ROM and RAM).  There has to be a better way.

Anyone have any suggestions?


-Jonathan		uunet!jvc!jonathan