Re: [stella] a question...

Subject: Re: [stella] a question...
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Wed, 7 Feb 2001 22:17:18 +0100
> ;Another question: this is my first attemp in stella programming...
> ;I want to learn to draw 2 players... but qhen they are in the same
> ;vertical position,
> ;something is wrong whit their size. I think that I must do something 
> ;whit the Vertical delay, isn't?
> ;But I don't have any idea about how to do it... I write the VDEL 
> ;rgisters and nothig happen

Actually the vertical delay is only usefull, if you update the
player graphics in alternating scanlines. If for example you
update the graphics for player 0 in the even scanlines and the
graphics for player 1 in the odd scanlines, you can use VDEL
to get both players displayed in the same scanline.

> ;Another thing: If I draw the PF0 and PF1, I have again troubles 
> ;whit the size of sprites:
> ;am I using more cycles than I can?

I think you probably do. Remember that you only have 76 cycles
total per scanline and that the display starts after cycle 22.
So anything that you want to be able to display on the far left
of the screen needs to be updated by then.

> ; Please, somebody help me... my algorithm really sucks, 
> ;which is the best way to draw 2 players?:

There is no best way to do anything on the VCS. It is all
specific on the game that you want to do. But you might
want to check out the commented source code for Combat from
Nick Bensema's website at
as an example of how to display two players.

Ciao, Eckhard Stolberg

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