Re: [NTLK] Alignment on "Mike's Newts"

From: John Charlton (
Date: Mon Jun 17 2002 - 01:26:10 EDT

Looking at the change of resistance across the screen as the pen tracks
across it, the change is very uniform in all areas (between 750 ohms and
1.4k ohms) except in the bottom right of the screen where the resistance
dips when it should be at its maximum value. This is just the place =
you tap the pen alignment cross. On my machine this also corresponds to =
micro-damage to the screen surface.

Thanks for that info Joel!

Ah, I think I'm beginning to see now, was confused but the lightbulb hit =
  If the resistance is non-linear across the screen, then there's no =
where points will draw. The alignment routine works (or doesn't) by =
  since it will reject touches beyond a certain range and make you =
If the measured resistance at that corner is close it will run its =
and orientation for best fit. So people could experience arcs, half inch=20=

(12mm) shifts, etc. I feel lucky that mine is only 2mm out and is fairly=20=


Did a little reading on touchscreens, here's one company's limits on=20

> Functional storage limits: 90% RH at max 35=B0C for 240 hrs, =

I could believe that a Florida closet could exceed that. Thinking it =
be humidity I tried baking mine for ten minutes at 200 deg F (100C) but=20=

didn't detect much of an improvement. Hard to say, could be better. May =
for twenty or until it's golden brown. Could it be the first Newt virus?=20=

Born in a Florida swamp?

Anyone know of Calvin Grier and his project? Could be the solution for =
  if it comes to market:
and a new backlight to boot!


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