Re: C64 MMU POC

From: Jim Brain <brain_at_jbrain.com>
Date: Sun, 22 Sep 2019 14:57:19 -0500
Message-ID: <86781f58-caad-76b8-732b-8f8fcd041388_at_jbrain.com>
On 9/22/2019 2:37 PM, Mia Magnusson wrote:
>
> Perhaps use extra addresses in the VIC-II address space? (Not sure if
> anything bad happens if you touch those addresses though).
Can you write to RAM under VIC-20 registers?  Remember, the unit sits in 
the RAM sockets, so it only gets writes if RAM is written.
>
> Maybe you could put registers in the $FFxx range like on the C128, with
> enable/disable in the regular I/O space.

I think that would work, as writes bleed through to RAM with ROMs banked 
in, but reads would not work, so it'd be best to use this for the 
"quick, set my mapping, no need to read" use case.  I'm not sure folks 
want to bank out ROMs all the time to read the MMU config, but could be 
wrong.

Jim


>

-- 
Jim Brain
brain_at_jbrain.com
www.jbrain.com
Received on 2020-05-29 22:41:21

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