CGoLf Challenge: ROT-13 transform standard input

[Hunting]

Your task here, is to build a CGoL oscillating signal circuitry that ROT-13 the input glider stream. This is CGoLf, so fewest amount of cells win.

Your signal circuitry must does this:

Code: Select all

Repeat till the input ends:
    Take 8 bits of input
    If 'A'(01000001) <= input <= 'Z'(01011010):
        If input < 'N'(01001110):
            Output input+13
        Otherwise:
            Output input-13
    If 'a'(01100001) <= input <= 'z'(01111010):
        If input < 'n'(01101110):
            Output input+13
        Otherwise:
            Output input-13
    If the above two conditions are not satisfied:
        Output input

Standard I/O
Your signal circuitry must input and output raw byte stream, which are represented as gliders in a glider stream. The glider stream period can be arbitrary. (The input and output glider stream can have different periods.) When there's 8 "no-gliders" in a row, you may assume the input ends. You have to specify where does the signal circuitry takes input and where does it outputs.