At 03:43 PM 8/20/97 +1000, you wrote:
>Maybe I've missied something, but, is it not easier (no diodes and
>standard shift-register) to use the shift-register to shift IN the
>switch positions.
>
>In a normal setup the BCD outputs of the switch present a logic 1 or 0.
>Therefore, if they are connected to the 12 parallel shift register
>inputs, the value of each input would be serially shifted in.
>


Much better! Remember to put in 12 pull down resistors from the switch
outputs to ground (if the switch commons are tied to +5v).  Then use 8 bit
parallel in/serial out 74HC165's. They cost about $0.33 each in 100s.


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