William Levak wrote: > > It has two 6522's and a 6526. > VIA1 $1800-180F serial bus > VIA2 $1C00-1C0F drive mechanism > CIA1 $4000-400F fast serial bus > > The only thing used in the 6526 is the parallel port B, SP, and CNT. > Since the system uses this port for fast communication, it may reset your > information during normal operation. You may have to load a routine to > the drive memory that disables the system interrupts in order to use the > TOD. > I think the TOD input of the 1571 CIA is just not connected to anything. Also note that some 1571 were even shipped with a 8520 CIA (from Amiga), which has the TOD clock replaced by a straight binary counter. Nicolas - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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