>Assuming the displays are common-anode, you'd use NPN transistors.
    >To drive a digit, you set its common wire HIGH, set the appropriate
    >segment wires LOW, and let the other lines FLOAT.  If you want
    >decimal points, then you can get 9 digits with 9 I/O pins.

I like this a lot.  Very clever.  The kind of not-PIC-specific thing I find
very useful.  Are the weak pullups on a PIC too weak to interfere?  I
suppose you can still use the same 8 lines for switch inputs as well, for
certain cases, and certainly if you have fewer than 8 digits (4 digits and
a 4x4 switch array in 8 pins should be easy?)


    We got to have different segment maps for each digit..

I think careful use of rotate would be sufficient...

BillW