[Coco] 512K AND Beyond??? How FAR Beyond???

Zippster zippster278 at gmail.com
Wed Dec 27 16:10:29 EST 2017


Sure, you can’t use it as video ram, and when mapped to the the 64K address space, the onboard
DRAMs still receive writes, although reads can be suppressed via SLENB.

All that remains is to write software to make use of it, which is the major issue with any new
hardware that doesn’t emulate pre-existing CoCo hardware (unless it doesn’t need software,
like a video option).

- Ed



> On Dec 27, 2017, at 12:55 PM, Richard Cavell <richardcavell at mail.com> wrote:
> 
>   Hi everyone. I just want to offer my two cents.
> 
>   Would it be possible to set aside a few bytes of the address space to
>   function as bank-switching registers, and then construct a custom
>   bank-switching mechanism to add more memory via a cartridge?  Using
>   this mechanism you could add any amount - even gigabytes.
> 
>   But the 6809's ability to retrieve and process that memory is limited.
>   Once your program genuinely needs more than a few megabytes of RAM to
>   be simultaneously accessible, the 6809 is no longer the correct CPU to
>   be using.
> 
>   Richard



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