[Coco] Super Cartridge

[Juan Castro]

On Wed, Jan 16, 2013 at 6:50 PM, john dumas <JohnDumas at austin.rr.com> wrote:
> On 1/15/2013 9:38 AM, Luis Fernández wrote:
>>
>> There is the possibility of having a cartridge that can accommodate all cartridges coco, perhaps with a SD memory and through switches or display can select say 300 and that they pass the address & hC0000 as cartridges true (perhaps read only as rom) and so they can be used by machines without HDBDOS or RGBDOS or Nitros9, or even by machines 4k, 16k, 32k ....
>
> Possible so.
> I did something similiar with an Atari 2600 cartridge.
> A large flash eprom with the upper addresses controlled by miniature switches.......
>
> Of course the atari cart is a simpler beast with no interrupt, etc. And there are only a couple of discrete rom sizes to emulate......unless you add bank switching hardware, which I did not. The early, real classic, games didn't use bank switching and those are what I wanted to play........
>
> No doubt the hardware gurus here could crank out a much better cart design for the coco.

Allow me the opportunity to ask a related question: how do 32KB
cartridges in the CoCo work? I thought the only address space
available to them was from C000 on, I/O ports excepted.