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!
:)
-Chris
-
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/
