Date   : Wed, 26 Oct 2005 09:45:55 +0100
From   : Richard Gellman <splodge@...>
Subject: Light pens.

I can get my hands on a BBC Micro light pen from a friend (its in a box 
of his doing exactly nothing). This has prompted me to think along the 
lines of touchscreen-esque control systems driven by the all-powerful 
BBC Micro.

My question is, knowing roughly how the pen works, is there a way of 
being "notified" (e.g. IRQ) when the CRTC has latched a pen position, or 
is it simply a case of polling the CRTC like mad until a flag is set?

-- Richard