Light Pens ...

From: Megan <mbg_at_world.std.com>
Date: Mon Jul 16 17:27:28 2001

>Ok, my mind is still blown. How does a light-pen drawing program work
>then? (Or is a light-pen drawing program not possible?)

By putting up some sort of target which does provide the light-pen
with a light signal. The target is designed in such a way that you
cannot move the pen without hitting some part of it, and the software
sees a light-pen hit and *re-centers* the target on that point,
effectively moving it to where the pen is now pointing.

                                        Megan Gentry
                                        Former RT-11 Developer

+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '_at_' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg KB1FCA |
+--------------------------------+-------------------------------------+
Received on Mon Jul 16 2001 - 17:27:28 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:33:52 BST