Re: [stella] reading paddles

Subject: Re: [stella] reading paddles
From: p.cavina@xxxxxxxxxxxxx (Piero Cavina)
Date: Fri, 6 Dec 1996 18:40:05 +0100
From: jimn8@xxxxxxxxxx (Jim Nitchals)

>To reduce the overhead of your paddle routines, you could interleave
>the reads (only read one paddle every 2 scan lines, and alternate)


Thanks for these ideas...

>If you have dead cycles in your display code, you may find this useful

>    lda INPUT0
>    asl
>    adc Pot
>    sta Pot

that's smarter code... :)

>I wonder if doing an extremely short capacitor dump cycle would cause
>the potentiometer values to change quick enough to read the pots in
>a short loop.
>    lda #$80
>    ldx #0
>    sta VBLANK
>    stx VBLANK
>then read the input ports *really quickly*.
>Just an idle thought - perhaps someone will give it a spin.

Do you mean 'stop and wait until the capacitor is charged'? Something like

     BMI charged
     INC Pot
     BNE loop

No, this isn't possible - it is the first thing I tried - It takes too much
time; that cycle must be done during the main display loop.

>It's a common problem.  You need to compensate for it in software


>I believe the Supercharger sound test program de-jittered the paddles.
>I can't find the source to it at the moment, sorry, but it was posted
>to this list a while back.

At this point I do need the source code of a paddle game. If anyone has it
please post it to the list or send it to me!


Current Thread