Re: Disabling memory refresh in UltiMax mode Re: 6510 handling of $00 and $01 registers

From: Nicolas Welte <*no_spam_at_x1541.de*> Date: Sat, 10 Dec 2011 21:09:40 +0100 Message-ID: <4EE3BC84.5050907@x1541.de> · no_spam_at_x1541.de

On 10.12.2011 20:51, Segher Boessenkool wrote:
>
>> To bad no one has yet been able to find a software trick to distinguish
>> between the 6510 and the 8500. :)
>
> They didn't?  I thought you could do the timing thing with the high
> port pins?  Very unstable of course...
>

Also, I think reading data from the previous half-cycle from unconnected 
address space (or color RAM) works only with 85xx CPUs. Also unstable of 
course, though in one case where it wouldn't work in one of my machines, it 
turned out to be a defective CIA chip. After replacing, the machine behaved 
fine as expected.

Nicolas

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