Question about a Sup-R-Mod II de-installation

["Chris Alaimo" <cpalaimo@gmail.com>]

So...  I have an Apple ][ with a Sup-R-Mod II installed.  The unit
itself is attatched to the inside of the case like usual.  it is
connected to a small board with a pin header that iis plugged into the
socket at position F14, where I believe a 74LS259 chip should be. First
of all, what is this little board for?  That board is then plugged into
a card in one of the expansion slots, which I therefore assume is an 80
column card.  Basically, I would like to uninstall this mess.  I have
no need for an RF modulator, and I have another 80 column card that is
less "messy".  Unplugging everything causes the system to not boot up
properly, so I imagine that I need to get a 74LS259 chip to stick in
the socket.  Where do I find one of these?  I can pull the chip out of
my ][+, but then I will need a replacement for that computer.

Thanks,

Chris