6-4 Input NOR Buffers
<UL>
<LI><b>M617B</b> is a drawing of DEC's M617B.</LI>
<LI><b>M617C</b> is a drawing of DEC's M617C.</LI>
<LI><b>M617E</b> is a drawing of DEC's M617E.</LI>
<LI><b>M617X</b> is a 'modernized' M617.</LI></UL>