At 06:38 PM 2/22/00 +0000, you wrote:
How did the
touch screen operate then, infra red beams?
For the HP150, yes. Emitters on the left side and bottom, detectors on
the right side and top. The resolution was good enough to select one of a
pair of characters IIRC (it cheated, and used 2 adjacent beams blocked as
to detect when you were midway between said beams).
>
> ISTR that I once saw a touch screen (in fact probably the only one I've
ever
seen) which
was some sort of transparent layer attached to the face of the
CRT, it looked rather like an anti-glare covering. It was nice as you
couldn't smudge it.... :-)
The HP Omingo 100 pocket computer uses a thing like that (you write on
the LCD screen with a stylus). It wears out _very_ quickly, though.
I have an Apple Newton 120 that uses a stylus. This one works well,
there are no marks on it after a number of years of use.
Joe
-tony