<> So My Compupro RAM16 (64k static) in the NS* (system A) has all banks <> enabled and if we hit e800H the FDC forces phantom/ and the ram16 is <> deselected for that address. < <Ah... I see... Now, the 4FDC does not have any connection to <pin 67, so it is not using phantom. But it should be easy to <implement... Can I just take the /CS (-NOT- chip select) pin <from the 2708 and wire it to 67? Maybe I need to -NOT- it first? You could but it would be bad juju. the normal drive for phantom/ is either an open collector driver (7406, 7438) or maybe a driver like 74126, 241, 244... to be active only when active low. Also you don't want that phantom/ going low from some other card from asserting CS/ on the 4fdc. Allison