Multiplexer channel selection

[Castor]

... but as the PIC will perform the A/D conversion ... a Porta Analog input has some good chance to be in use ... if you do not use another ADC input ( PortE 0,1 or 2 for a 16F877a )

Hey, thanks for the great answer.
It works like a charm. In fact I use a 16 bit external A/D converter so using PORTA pins as digital I/O doesn't pose an issue. What if the selection pins are scattered across two ports ? Can I get around that without selecting each and every output manually ? Or reworking the board ? (I didn't quite think about channel selection when I built it)

'DCD
'----------
'RE2 G1,G2
'RB7 A
'RB6 B
'RB5 C
'RC6 D