19 Mar
2005
19 Mar
'05
9:03 a.m.
On Sat, 19 Mar 2005, Pete Turnbull wrote:
On Mar 19 2005, 11:19, GManuel \(GMC\) wrote:
Also, light pen software can create a moving lighted spot for the pen to
track over dark screen areas...
Peter Wallace
It must be able to somehow. I have used a light
pen on a Commodore 64
with a
Graphics Program called Picasso's Revenge and
have drawn on the
screen with
it even on a completely black background. Not
sure how it does it
though.
It's just a question of sensitivity. The black portions of the screen
are rarely quite black, because the electron beam is not quite turned
off. Thus a suficciently sensitive lightpen can still detect the spot
as it scans past the pen's location.
--
Pete Peter Turnbull
Network Manager
University of York