Re: C64 buses when RESET is asserted

From: Segher Boessenkool <*segher_at_kernel.crashing.org*> Date: Sat, 13 Apr 2013 21:37:17 +0200 Message-Id: <A7F0FD35-958E-4B7D-9811-CD52E3E8D71E@kernel.crashing.org> · segher_at_kernel.crashing.org

>>> If you tristate the cpu, you still have half the cycle left for the
>>> write. Not much more difficult.
>>
>> You also need to monitor the BA (RDY) line, otherwise you'll run  
>> into trouble when the VIC does a badline and uses the complete cycle.
>
> But - generally - if this is done on power-up, then it could  
> possibly be done before VIC gets initialised (I assume - maybe  
> wrong now - that it powers up with "screen disabled" state)?

It powers up in a random state.  Most register bits will *usually* be 0.

Segher

       Message was sent through the cbm-hackers mailing list