Light Pen for PCjr or PC?

From: John Foust <jfoust_at_threedee.com>
Date: Mon Jul 16 08:52:25 2001

At 09:44 PM 7/14/01 -0700, Fred Cisin (XenoSoft) wrote:
>When the computer hears from the lightpen that it sees the light, it knows
>(I promised over-simplification!) where the light is at that instant, and
>therefore, now knows where the lightpen is.

It's all about light detection and horizontal and vertical
scan timing. There were light pens for the Amiga that worked
at a distance and with projection televisions, for example.
The same principle is used in old console games for the
"gun" that knows what you're pointing at on-screen.

- John
Received on Mon Jul 16 2001 - 08:52:25 BST