Re: Microcontroller "PEEKing" into C64 memory?

From: silverdr_at_wfmh.org.pl
Date: Thu, 21 Jan 2016 21:33:26 +0100
Message-Id: <6DBB038C-29B2-46B2-86D0-49DD35D7E143@wfmh.org.pl>
> On 2016-01-21, at 21:18, groepaz@gmx.net wrote:
>>>> 
>>>> If what you need is mirroring of a portion of C64 ram I have a FIFO
>>>> based bus snooping design that could work, but I haven't had a chance to
>>>> verify it.
>>> 
>>> I'd also be interested in a design, as I have a few ideas that need such
>>> an integration.  I had been planning to implement 8 registers in a CPLD
>>> with dual port access, but maybe there are better ways to do this...
>> How do CPU carts access the RAM? I mean how the external CPUs do it from the
>> EXPANSION port.
> 
> using the DMA line (which halts the internal CPU and removes it from the bus)

Well, that's what I mean - if all what's needed is to peek a few bytes off some location from time to time? Or is it supposed to be completely invisible to the system?

-- 
SD!


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Received on 2016-01-21 21:02:13

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