16 Jul
2001
16 Jul
'01
4:01 p.m.
On Mon, 16 Jul 2001, Tony Duell wrote:
Ok, my mind is still blown. How does a light-pen drawing program work
then? (Or is a light-pen drawing program not possible?)
Sellam Ismail Vintage Computer Festival
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International Man of Intrigue and Danger http://www.vintage.org
So here's
a trick question .. what happens when a person holds
a lightpen to a dark section of the screen. Is the lightpen
Nothing happens (literally). The light pen never sees any light, so it
can't send a signal to the video card, so the CRT controller can never
report the position.
completely blind unless come pixel is lit up?
Yes.