Buying or making graphics tablet

[JimS]

You seem to know a bit about the Koala Pad, as you say it has a number of X and Y sensors. What do these sensors consist of?

The Koala Pad acts as if it was a pair of variable resistors one in each direction. So when you touch the pad, there's an x and y resistance that corresponds to the point you touch. The paddle hardware in the computer reads that out as a pair of values. I'm more familiar with the Atari 8-bit machines. The paddles read from 0-255 which was greater than the screen resolution in color mode.
It makes me wonder though... the resolution limit was mainly a result of the computer. If you used a a/d converter with more resolution, say 10 bits, could you get more meaningful resolution out of the Koala Pad? It's still a rather small drawing area though.

[JimS]

I'm not sure if the Amiga can do analogue to digital conversions on the joystick ports.  I've never seen paddle controllers used on a an Amiga.

The hardware is there to read analog resistance on the Amiga's joystick ports. I've never seen anyone use it either.... although I think some of the 3-button mice used the analog inputs as the 3rd button.... after all, a button is just a variable resistor with only 2 values... 0 and infinity. ;-)