[sdiy] Shift register sequence period

[Eric Brombaugh]

Tim Stinchcombe wrote:

> As the circuit stands, yes it is linear, but the effect of the inverter (in
> this case) is to make it 'inhomogeneous'

Ah - that makes more sense. I was reading through my material on finite 
field algebra and they kept insisting that mod 2 addition (XOR) is 
linear. I couldn't figure out how you could use linear ops to get a 
nonlinearity...

> Thanks to those who chipped in with useful thoughts, insights and
> calculations.

Thank you for chasing it down and writing it up so nicely. This has 
clarified a few things for me.

Eric