DC Carry Cahin, 6 Interconnected Diode Gates + 1 Inverter
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<LI><b>R181A</b> is a drawing of DEC's R181A.</LI>
<LI><b>R181C</b> is a drawing of DEC's R181C.</LI>
<LI><b>R181X</b> is a 'modernized' R181.</LI>