Re: [stella] bipolar joustpong

Subject: Re: [stella] bipolar joustpong
From: ecwilkso@xxxxxxx
Date: Fri, 5 Sep 2003 14:08:19 -0400
Quoting KirkIsrael@xxxxxxxxxxxxx:

> Well, surprise surprise, even the humblest version of this 
> logic (where I set both sides of the playfield to the same 
> value, and just toggle that on or off every 11 scanlines)
> can set my admittedly sloppyish 2 line kernal well into 
> a 2.5 kernal or so, depending on the branching. So I think
> I'm in dire need of a kernal rewrite there.

Hmmm.  I'm not sure I understand this...I'll have to think
about it some more.  But if your blocks are 11 scanlines tall,
then you can break the processing into 11 pieces and do a
little bit on each line (of course you have to do if for both
players).  So...for each individual block, you effectively
have 5.5 scanlines to use, minus the processing for the bats
and the ball...that sounds pretty doable.  The rotating byte
method seems reasonable to me, BTW.  Might save a few cycles
if you merge the 2 walls together, alternating bits in the same
byte(s).  Then you only have to fetch and rotate one byte per
level instead of 2?  You'll have to rotate twice, once for each
wall, but...I don't know where I'm going, so I'll shut up now.

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