a first amplifier configured for amplifying {HEAD ~ the data} received from the first I/O port and outputting the amplified data to {TAIL ~ the second I/O port}; and 
a first amplifier configured for amplifying { HEAD ~ the data } received from the first I / O port and outputting the amplified data to { TAIL ~ the second I / O port } ; and
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH