On Fri, 11 Oct 2002, Eric Ball wrote:
> In absolute memory map terms, $0000 - $0FFFF is taken by the TIA & RIOT.
> Although neither uses the full address space, they don't decode all of the
> address lines, causing the same registers & RAM to be shadowed at multiple
> memory locations (like the RAM in the RIOT showing up at $0080 - $00FF and
> $0180 - $01FF).
Almost! I think you have an extra "F" in there. Or maybe it's just an
incomplete specification. :) All of that space isn't taken by the VCS
internals, but the memory shadowing does indeed take place as you say.
For a complete and quite exhaustive 2600 memory map, check out
http://web.mit.edu/ecwilkso/www/VCS_hardware
There, I've got the full 2600 memory map (in 2 formats) and also the
individual maps for the TIA and the RIOT. Enjoy!
Oh! And whoever is currently kicking the FAQ, feel free to add this in.
It should be there.
-Chris
> However, since the full address bus is available at the cartridge slot,
> cartridges can snoop the bus and implement FE (aka JSR) and 3F
> bankswitching where the trigger addresses were in the lower 4K address
> space.
>
>
>
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> However, since the full address bus is available at the cartridge slot,
> cartridges can snoop the bus and implement FE (aka JSR) and 3F
> bankswitching where the trigger addresses were in the lower 4K address
> space.
>
>
>
> ----------------------------------------------------------------------------------------------
> Archives (includes files) at http://www.biglist.com/lists/stella/archives/
> Unsub & more at http://www.biglist.com/lists/stella/
>
>
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