Re: [stella] Midified VCS...

Subject: Re: [stella] Midified VCS...
From: "John Saeger" <john@xxxxxxxxxxx>
Date: Mon, 19 Nov 2001 08:54:51 -0800
----- Original Message -----
From: <AutismUK@xxxxxxx>

> I mean, it can't be that complex.... there seem to be quite a few
> diagrams in the stella document.
> I can't imagine they designed it at the FET level, surely it must be
> a modular design ?

The devil is in the details my friend.  If only the programmers had followed
the rules...  One of my favorite examples of rule breaking is the re-writing
of the horizontal motion registers while an HMOVE is in progress.  In that
case, where does the sprite land?  Exactly how many extra pulses do we get?
In the moment, I'm thinking it may depend on the phase relationship between
the H01/H02 clocks and the write signals.  But I'm not smart enough to
figure out what the H01/H02 signals look like.  Do you know anything about

I'm not saying a completely high level approach wouldn't be interesting.
One might get as many as 90% of the games to work that way.  Even 100%
accuracy might be possible with a high-level approach to 80$-90% of the
design.  In many places something that looks like a register could probably
safely be replaced with a register.  In other cases, this certainly isn't


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