You can also visit your profile and see the audit trail of what you've done to each card, which includes a link to the archived card. Then you can "move" the card back to the board.

How to undo card archive on Trello?
I'm trying to visualize the differences on the output waveform of a modulator when using NRZ or a Manchester pulse shaping filter. To keep it simple, let's think of a binary PAM signal with an input bit sequence 101011. 

My thoughts are that with a Half Sine or a Raised Cosine pulse shaping filter, I will see the transitions between the 1's and 0's smooth out, but I'm struggling to think about the differences between the NRZ and the Manchester.
