I actually have a 3/50 with a 4M expansion board installed. It works
pretty nicely except that it isn't seated very firmly. It actually consists
of two or three separate boards which have plugs descending from the
undersides, which go into sockets on the motherboard where certain chips used
to be, and that's pretty much all that's holding it on. About once a year
I have to open the thing up and reseat the expansion, and that particular
box has to remain horizontal. I have most of my pizza boxes vertical in
special stands that I've made to save space, but the expansion just won't
stay in in that position.

   --James