Good idea, i'm going to check Jens.
Concerning the quadropppport, i have never believed that a piece of hardware that constantly use the clockport (i believe that the catweasel or the subway would always check if a disk or an usb thingie is connected) could share the port without something odd happening. Was it not intended to duplicate serial adapters?
I remember that i bought 3 or 4 of them at once six or seven years ago, and they were all damage, probably because of an unproper use. I made one of them repaired by Amigacenter, our local french fellow genius amiga repair man, for quite a lot of bucks, but i have finally never dared to use it...