HP21MX booster board?

[Jay West]

I am doing a little basement cleaning and pitching some things. Was tossing 
an HP frequency analyzer that was in bad shape and decided to pop the cover 
and grab the cpu board (the cpu board is a 21MX M-series). Also got 64k 
memory & controller :)

My question is two fold -first, what's necessary to use this M series board 
as a regular processor. I see the base instruction set on the bottom plus 
two additional non-standard microcode cards. I can just remove those, but 
didn't know if any changes to the M series board were required. Second, 
there is a board I've never seen before mounted under the mainboard on the 
opposite end of the microcode. The board is labled "booster board" and is 
about 1/2 the size of the main cpu board. I would normally think this was 
just a specific board to the frequency analyzer, but, I think I've heard Bob 
Shannon talk about this booster board before in more general terms. Should I 
keep the booster board?

Jay West