The BigIOinput library reads unlimited digital inputs from any parallel to serial input hardware based on the 74'595, e.g., Mama's Big-IO-input 64-bit parallel-to-serial input card. It has a map option to rewire in software.

Functions

BigIOinput(size, clock, shift, qh)	// size and pins

load()		// load register from external inputs

= shift()	// shift one bit from register
= shift(size)	// ... size bits ...

= read(position)                	// read bit at position
= read(size, position)          	// ... size bits starting at position
read(size, position, buffer)    	// ... to packed binary buffer
read(size, position, buffer, map)	// ... permuted by map

bit and byte indices, positions and values are all zero-origin little-endian
so pointers to int, long, etc. should work as expected with Arduino avr-gcc
assuming extra high-order bits are set to known values, e.g., zeros.