http://www.perlmonks.org?node_id=11136270


in reply to Re^7: Split any number into string of 8-bit hex values (=1 byte)
in thread Split any number into string of 8-bit hex values (=1 byte)

Note that for 200, C8 is a negative number, so the 00 is required to make it so that C8 00 is positive.
Ah, that might be the reason for that odd trailing '00' in the OP