Re: [stella] Player data loading...semi newbie

Subject: Re: [stella] Player data loading...semi newbie
From: Chris Wilkson <ecwilkso@xxxxxxx>
Date: Wed, 17 Oct 2001 16:17:26 -0400 (EDT)
On Wed, 17 Oct 2001, Erik Mooney wrote:

> Actually, the concern is that the technique requires +/- 384 consecutively
> addressable bytes of RAM.  The Superchip doesn't have that much, although
> you might be able to pull it off in a two-line kernel that didn't use the entire
> screen vertically (think Defender).  How does Megacart distinguish RAM
> read/write?  It would have to be a fairly high-order address line (A9-A11)
> for this to work.

Hmmm....good point.  I was thinking that you'd only need as many bytes as
lines in your kernel.  Your index could wrap around from the end of the page
to the beginning.  Will Y-indexing work like this?  Or does it actually go
to the next page?  I don't know if it's signed un unsigned...

But regardless, the Superchip only has 128 bytes.  I always forget that you
use twice the memory space because of the read/write complication.  The
Megacart allows up to 2K RAM selected at a given time, choosing from up
to 128KB of total cartridge RAM.  But it only supports 512 bytes of
contiguous RAM, using A9 as the read/write line.

> >(*)  Don't set the RAM on fire, or subject it to nuclear reactions, but
> >otherwise....????
> Aww, c'mon, VCS hardware is legendary for its indestructibility :)

Well....have you ever *tried* to set a chip on fire?  :P  And how many times
were you able to obtain a verified nuclear fission reaction?  And if you've
actually done fusion, I have a job for you!  And so do a lot of other people!



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