At 11:51 AM 10/21/2019, Tony Duell wrote: >> Theinfrared array you're thinking of was invented at PLATO, for flat panel >> (plasma) displays. They don't work for CRTs because of the convex screen. > >My HP150 will have to disagree with you there.
<https://en.wikipedia.org/wiki/HP-150#/media/File:Hp150_touchscreen_20081129.jpg>https://en.wikipedia.org/wiki/HP-150#/media/File:Hp150_touchscreen_20081129.jpg - John
