Re: [stella] Timing

Subject: Re: [stella] Timing
From: Rob <kudla@xxxxxxxxx>
Date: Tue, 15 Jul 2003 20:33:25 -0400
On Tuesday 15 July 2003 19:49, jesse@xxxxxxxxxxxxx wrote:
> life of me I can't find any comprehensive documents explaining how to do
> timing on the 2600 (I've been trying to count scanlines, but I think I need
> a little guidance). Anyway, if anyone has any suggestions (or code samples

What you're trying to do is actually pretty different than what people usually 
talk about as "timing" on the 2600.  You basically have a screen A you want 
to display and a tone you play meaning "keyed" and another (presumably blank 
and silent) screen B for "open".

Try adapting one of the "how to draw a playfield" tutorials such that every 60 
frames it switches between screens A and B.  You could make screen B 
something like

   LDY #192
   BNE LoopB
; and then vblank...  set your volume to 0 there

You really don't have to worry about scanlines or cycle counting at all except 
to make sure you end up with the same number of lines in both ScreenA and 
ScreenB (and of course that they're close to 262/312).


Archives (includes files) at
Unsub & more at

Current Thread
  • [stella] Timing
    • jesse - Tue, 15 Jul 2003 19:03:21 -0400 (EDT)
      • Jason Wambach - Tue, 15 Jul 2003 19:12:11 -0400 (EDT)
      • Rob - Tue, 15 Jul 2003 20:34:56 -0400 (EDT) <=
      • <Possible follow-ups>
      • Manuel Polik - Wed, 16 Jul 2003 02:09:21 -0400 (EDT)