[atari7800] Re: [personal] No luck with doing paddles on the 7800

I think I see the problem. Here is the code that reads the paddle. When
INPT0 goes high you store Y in paddleVertPos, but as you continue through
the loop you keep de-incrementing Y and since INPT0 stays high you keep
updating paddleVertPos. So when you leave the loop paddleVertPos will always
be either 200 or 0.

DisplayKernel
   ldy #200 - MIN_Y
.kernelLoop
   sta WSYNC
   lda INPT0
   bpl .nextScanLine
   sty paddleVertPos
.nextScanLine
   dey
   bne .kernelLoop


Dan

-----Original Message-----
From: atari7800-bounce@xxxxxxxxxxxxx [mailto:atari7800-bounce@xxxxxxxxxxxxx]
On Behalf Of Dennis Debro
Sent: Monday, September 24, 2007 10:23 AM
To: atari7800@xxxxxxxxxxxxx
Subject: [personal] [atari7800] No luck with doing paddles on the 7800


Hi there,

Apparently I'm missing something. I've gone over my code a number of times
and can't seem to find my error. I've sent it to a friend to test on his
7800 and he can't get the paddles to work. I'd test it on my system but my
power supply is blown at the moment :-(

Could one of you take a look at this and point out where I'm missing it? The
paddle should move up when the paddle is rotated clockwise and move down
when rotated counter-clockwise.


Take care,
Dennis

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