Crystal Clock, positive and negative pulse outputs, 5KHz to 10MHz
<UL>
<LI><b>M405A</b> is a drawing of DEC's M405A.</LI>
<LI><b>M405B</b> is a drawing of DEC's M405B.</LI>
<LI><b>M405X</b> is a 'modernized' M405.</LI></UL>