Re: [stella] a "pot" of confusion

Subject: Re: [stella] a "pot" of confusion
From: gentlben@xxxxxxxxxxxx
Date: Wed, 26 May 1999 10:38:48 -0700
> This is completely correct from a programming point of view, but just a
> couple minor electrical nitpicks... "Pot" is short for potentiometer,
> which is a variable resistor and is pretty much all the paddle is.  (The
> pots don't discharge or recharge.) When you write the 1 into bit 7 of
> VBLANK, a capacitor in the console gets grounded and drained.  It stays
> grounded until you write a 0 to that bit.  Then, it starts recharging
> through the potentiometer; the paddle read bit will go high when that
> capacitor is fully recharged.  How long it takes to recharge is determined
> by how much resistance the paddle's potentiometer is currently supplying,
> and that's how you get the paddle's position.

yeah, i understood all along what the paddles are (but thank you for the
technical
explanation of it :) i knew a little bit about potentiometers, but i wasn't
sure how to
determine the position of the paddle through one bit, seeing as how, by
comparison,
the commodore 64's sid chip has a 8 bit register for reading a value (0-least
resistance, 255-most resistance) or whatever...

dee


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