Hello! Rob Clarke wrote: > WRT to the 6525, a bad one can 'black screen' the system. The one that > handles the keyboard also controls the 16k bank that the vic-ii sees. > When I got that batch of 6525's a few months ago I did not have a > socketed 6525 in any of my cbm-ii machines to test with but I now have a > P500 with a socketed 6525 and I know that some of the bad ones will stop > the machine from visibly booting. OK, that's indeed a valid theory. But I recall from previous conversations from Steve that the activity on the address lines was somewhat different from a working one, which a bad 6525 would not produce. But this should be rather simple to check? One could just check the voltage on these A14 and A15 pins coming out of the TPI? Regards, Michau. Message was sent through the cbm-hackers mailing listReceived on 2012-10-02 20:00:38
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