Switches on the front panel are connected to {HEAD ~ like designated inputs} to {TAIL ~ PLA} 31 as shown 
Switches on the front panel are connected to { HEAD ~ like designated inputs } to { TAIL ~ PLA } 31 as shown
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH