On Wed, 28 Mar 2001 ncoplin@orbeng.com wrote: > >On the plus/4, DATA is output from bit 0 of the 8501 I/O port (inverted) > >and CLK from bit 1. However, DATA is read in from bit 7 whereas CLK is on > >bit 6 - ie. the order of the signals is reversed. > Thanks for the info. To complete the picture, where is ATN connected to? ATN out is bit 2 of the on-chip I/O port. Like the 64, it is only available as an (inverted) output. The nice thing about the 264 series is that because the serial bus uses the processor I/O port, reads and writes of the port can use zero page instructions. Hopefully this will compensate in part for the slower clock speed. Richard - 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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