Re: Could you make a 'new', 'better' computer from the C64 just by reprogramming the PLA?

On 10/27/2021 3:03 PM, Claudio Sánchez wrote:
> Hi all.
>
> It seems to me that what makes the C64 "the C64" is the way the PLA is 
> programmed so it maps the different chips as I/O addresses in the 
> memory space.
>
> But as seen in the many different computers based on the 6502, the way 
> the 65xx architecture is designed is that "every thing is a memory 
> address", similar to *nix philosophy of "everything is a file".
>
> So, leaving compatibility out, could you make a 'better' computer out 
> of a standard C64, just by reprogramming the PLA and moving the memory 
> addresses used by the different chips in a better more efficient way?
>
> Thanks all.
>
> -- 
>
> Saludos y cerveza.
>
I don't know if it qualifies as "better", but the PLA could be extended 
to offer some things that people tend to find useful:

  * A way to map out internal KERNAL for an external KERNAL that is "All
    RAM mode" aware
  * A way to enable VIC-II access for external memory (maybe not just a
    PLA change, as I think the address lines from the VIC don't make it
    to the exp port, but you get the idea).

I'm sure there are other things we've worked around that might be nice 
to have


jim



-- 
Jim Brain
brain_at_jbrain.com  
www.jbrain.com