z80 card dip switches

[jon@i-manila.com (Jon Co)]

I have 2 z80 cards.  They are both unbranded.  About the size of a
language card.  There's an LED in the top middle part of the card and
4 dip switches under it.  One of the cards dont work as I tried to run
it with all 16 possible combinations.  Since the chips are socketed I
will be checking this card out later on part by part.  The other card
worked on my //e.  What's the function of the dip switches?  The LED
blinks when cp/m is in use and while programs are running.  Does cp/m
make use of the //e's auxillary RAM? or does it run like it did on the
II+?

Also, I did some experimenting and plugged the working card into my
IIGS, and of course it didn't work.  either screen full of garbage or
"cannot detect z80 softcard"

What software, besides cp/m required this z80 card?