[Coco] Memory expansion

[RETRO Innovations]

On 8/11/2018 12:43 PM, Bill Gunshannon wrote:
> A quick question for our hardware gurus.
>
>
> Would it be possible to make a cartridge memory expansion?
>
> That is a memory expansion on a cartridge that could be plugged
>
> into the MPI instead of inside the COCO itself.  I can think of
>
> some things that might be problematic but I am no expert by any
>
> stretch of the imagination.  So, I defer to the real experts.
>
>
> bill
>
>
>
It's possible, in two ways:


  * Use SLENB to move internal RAM reads out of the way, and map RAM
    onto the bus (except for special locations, like the ffxx bank). 
    This is available in a cart called MOOH, for the Coco 1 and 2.  I
    suspect it also will work for the 3, but it only has 512kB, as I recall.
  * Page RAM into the cart port area ($c000-dfff). 8kB pages.

MOOH is probably a better option, as I think you can map in 32kB of RAM 
at a time.


Jim

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