Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!ns-mx!pyrite.cs.uiowa.edu
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: comp.human-factors
Subject: Re: Track ball on a keyboard?
Message-ID: <6450@ns-mx.uiowa.edu>
Date: 12 Jun 91 17:55:20 GMT
References: <1991Jun12.155623.15673@wpi.WPI.EDU>
Sender: news@ns-mx.uiowa.edu
Lines: 17

From article <1991Jun12.155623.15673@wpi.WPI.EDU>,
by dmorin@wpi.WPI.EDU (Duane D Morin):
> 
> As a user of a trackball (more specifically, a "thumb ball") I have to
> agree with an earlier post that says they're not as accurate or as
> fluid as a mouse.

Proper trackballs are large enough to be worked by the palm of the hand
for coarse motion, and by the fingertips for fine motion.  To work this
way, your ball needs to be about 3 inches in diameter, and it must protrude
at least half-an-inch from the housing.  Given a trackball built like that,
you should expect positioning speed and accuracy better than a mouse once
you get used to it, but no keyboard mounted trackball that I can think of
would meet this requirement, at least not in this age of detatchable
lightweight keyboards.
					Doug Jones
					jones@cs.uiowa.edu