The timer, comprising {TAIL ~ digital circuitry} is easily interfaced to {HEAD ~ a digital control computer} 
The timer , comprising { TAIL ~ digital circuitry } is easily interfaced to { HEAD ~ a digital control computer }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD