🚀 go-pugleaf

> I guess I was hoping for too much, but I saw some interesting questions
> raised about scrolling windows w/steady backgrounds and other assorted tricks
> that would be fun to know about... but instead of answers to the questions, 
> just ongoing discussions of pascal v. c w/ lots of "let's include the
> entire message in the follow up whether we're replying to it or not."

I agree.  I've answered some of those questions (about the scrolling windows
w/steady backgrounds), and so on.  Now I have one:

Jan Ole Suhr wrote a program called WOWII.  It is a Protracker module
player.  I'm not interested in the module playing source, as many of you
know, I've already written the source and released it to the public.  But,
the question I have deals with his ModeX implementation.

I know how to pan around in the tweaked VGA modes.  I don't want an answer
to that.  What I want to know is how to make a split screen.  He does that
with his (un)Real-time Spectrum Analyzer.

I do know that on a split-screen, you can pan the upper half around.  
Somehow, through some VGA register that I have no idea how to use because
I can't find a decent manual, you can specify the scan line for the new
screen to begin.  You would need to also output a word telling the VGA 
card what offset in memory to display at this scan-line.

Could anyone tell me how to do this?  I know assembly and actually prefer
it.

Thanks in advance,
Josh