Re: [stella] Repository

Subject: Re: [stella] Repository
From: Piero Cavina <p.cavina@xxxxxxxxxxxxx>
Date: Mon, 23 Feb 1998 17:45:14 +0100
At 06.11 23/02/98 -0800, Greg Troutman wrote:

>Nick S Bensema wrote:
>> > 1- learn the basic concepts from the programmer's guide. And I mean
>> > "basic": don't waste time on VDEL, for example! What's the use of VDEL,
>> > anyway? ;-)
>> It's my understanding that when VDEL is enabled, a player's graphics don't
>> change immediately when its data register changes; it waits until the
>> next write to player data before it makes the change.  This was intended
>> to allow single-scanline positioning in double-scanline kernels, but
>> its most common use is in six-digit scoring routines.

I was almost joking, VDEL is very important, thought maybe it's not a clear
issue at all - and I did't use it in Oystron.
Exercise: take a simple kernel, let's say Adventure, remove the VDEL (just
change the STA VDELPx to two NOPs with PCAE) and see what happens.


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