$ perl -le " print chr hex q/C0/ " |od -tx1
0000000 c0 0d 0a
0000003

$ perl -le " print chr 255 " |od -tx1
0000000 ff 0d 0a
0000003

$ perl -le " print chr 256 " |od -tx1
Wide character in print at -e line 1.
0000000 c4 80 0d 0a
0000004