In digging through my ram board bits, I ran across a board
that seems to be an 8mb ram board for a KA630, but, I do
not see a listing for it in the field guide.  It is a National
Semiconductor NS638 board, with no other markings on
it.  It has some sort of two position toggle switch on the
top edge but I don't know what it does or how to set it, if
needed.  Any info or insights as to what this board actually
is, is kindly appreciated.

Thanks

Bob Keys