RE: [stella] Gravity Ball v014 - Please help!

Subject: RE: [stella] Gravity Ball v014 - Please help!
From: "Dennis Debro" <ddebro@xxxxxxxxxxxxx>
Date: Tue, 3 Jun 2003 21:51:06 -0400
Hi Rob, 
> Please find attached the source code and binary for the current
version of
> Gravity Ball.  Its not much yet.  There are no controls just a looping
> visual demo.   I want to show this demo at the Midwest Classic this
> Saturday.  I need some help getting it debugged.

As pointed out already Z26 reports 260 scan lines for the title and 282
for the game display. If you changed lines 1201 and 1230 to ldy #3
you'll get 262 lines.

The screen jumps a little when switching from the title and the game
screen too.

You seem to be doing a lot during the vertical sync. This is a debate
that's been going on for sometime. It seems some consoles are more
sensitive than others to this behavior. I would recommend you moving
these computations out of the vertical sync and doing them during the
vertical blank. Some have been able to do computations during vertical
sync with no problems but other haven't. Since you don't know how the
machine running your demo will respond, it's probably best to move it

In the game display the top part of the screen moves down (sort of like
2 reverse mountains). Is this behavior wanted? I've attached a screen
shot of what I'm talking about.

I haven't played on my CC, sorry. I only had time to run it in the

Good luck on getting this done in time and I look forward to seeing the
finished game. 

Take care,

Archives (includes files) at
Unsub & more at

Current Thread