Re: [stella] I live... again!

Subject: Re: [stella] I live... again!
From: Chris Wilkson <ecwilkso@xxxxxxx>
Date: Tue, 12 Feb 2002 01:59:15 -0500 (EST)
On Tue, 12 Feb 2002, MoonlightKnight wrote:

> Since I'm realitivly new to this, I have a question.
>
> I know that most of the original Atari games were written in 4K or less, but
> my question is this:
>
> Is it the game cartridge or the system that does the bankswitching? And if
> so so do you have to bankswitch at 8K or is it higher than that?

Hi Brian,

As far as the 6507 is concerned, it's just a single 4K block of memory.
Only the programmer and the bankswitching cartridge know the difference.
The cartridge watches the address lines for certain "hot" addresses to
be accessed and switches the proper bank into addresses $1000-$1fff for
the next ROM access.

You can bankswitch a single byte in and out if you really want to.  Each
cartridge maker had their own special way of doing it.  My cartridges
support the "standard" Atari format, up to 32K...it just breaks the ROM
into 4KB banks and switches them in whenever an address in the $1ff4-$1ffa
range is accessed.

-Chris



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


Current Thread