Hi Nate, Nate Lawson schrieb: > On Sep 21, 2011, at 3:22 PM, Segher Boessenkool wrote: > > It's 500 Kbit/sec inbound to the 1571. Some devices receive it just > fine, others don't. I'm going to try reducing the clock rate slowly > and see where it becomes reliable. If it truly is synchronous with if it is different behavior from drive to drive then this let's me think on different CIA revisions. 6526 vs. 6526A vs. 8520, you know even VICE does support two different 6526 types, the "old" and the "new" one which have some off-by-one clock cycle differences. I don't know about the exact details, but since the shift registers may be the worst studied/tested functional blocks of the CIA, this could be a reason. Maybe you want to have a look for a piece of CIA type detection code and check, if there is a relation beweeten "unreliable" 1571 drives and a certain CIA type. Womo -- ------ to obtain more infos about me, look up the page ------ ------ http://www.wmsr.de | wm (at) wmsr (dot) de ------ Message was sent through the cbm-hackers mailing listReceived on 2011-09-22 21:00:03
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