Re: Aw: Re: [stella] Incoming

Subject: Re: Aw: Re: [stella] Incoming
From: Ben Larson <wazzapfool@xxxxxxxxx>
Date: Fri, 1 Feb 2002 08:05:14 -0800 (PST)
Hey guys, thanks for the help and insight.  It appears
I will indeed be able to make the game flicker-less.

After fitting the tank graphic into one page and
making some kernel modifications to accomodate this, I
was able to remove the WSYNCS in the kernel as well
and get enough space for the missile-drawing algorithm
Manuel provided below.  This should not only make the
game nicer, but also save some ROM space.


--- Thomas Jentzsch <tjentzsch@xxxxxx> wrote:
> If you align (something like: align 256 + 120) the
> data P1/P2Offset are
> pointing to, then you can avoid the extra cycles for
> crossing a page.
> Then all code in your main kernel has a constant
> timing, which would
> allow you to remove WSYNC and get some more cycles.
> And that should
> allow you to add code for one missile (perhaps even
> both), and avoid
> flicker. 

--- cybergoth@xxxxxxxx wrote:

> Normal code to handle more than one missile would be
> something like
> Set up stack:
> LDX #$1E ; (1F if you do the ball too)
> Activate:
> CPY/CPX missile1Y
> PHP     ; (Pushes the zero flag into ENAMX!!)
> CPY/CPX missile2Y

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