128 and more input using a PIC16f628

[Ben Bradley]

Some people are telling me its not possible to multiplex serial out
parallel in shift registers.. As I've never used these.. is this true?
Or is it possible?

I forget the part numbers (you need the ones with the appropriate
features: load, clock, serial in, serial out), but I presume you mean
can you cascade (or 'daisy chain') such shift registers, and yes you
can do this for however many inputs you have. It's a simple way to do
it. The processor triggers the load signal (one time for each read),
then toggles a clock line and reads the input port for each bit of
input.