I have yet to find any information on these chips from National Semiconductor. They appear to be obsolete chips. Some of the connections can be deduced (like CLK1 and CLK2, Vcc and Ground), but others are not so clear. The purpose of the information here is to deduce the operation of Q2, and suggest a replacement . I can find no information on the APOLLO 3420 device, so I have no idea what it is or does. The dashed lines are where the terminals appear to be internally connected. It appears to be a ceramic case, with the name "APOLLO" and the number "3420" printed on grey plastic that is shrink-wrapped around the case. There are no other identifying marks.