Memory Driver, IC Inputs, 4 circuits, PDP8/I, PDP8/L
<UL>
<LI><b>G221A</b> needs a drawing.</LI>
<LI><b>G221B</b> is a drawing of DEC's G221B.</LI>
<LI><b>G221X</b> is a 'modernized' version of DEC's G221B.</LI>