I'm using a 3-button Logitech PS/2 mouse with a serial adapter in my 486, and it's been working fine. The mouse driver (CuteMouse from Phil's starter pack) has been detecting the mouse automatically in "Logitech mode", and everything has been fine and dandy.

A couple of days ago I got hold of some extra 16-bit ISA controller cards and was going to test them, to see if they were fully functional. The IDE and Floppy ports are working fine, but I can't get my mouse detected in either of them. The motherboard reports COM1 with the correct IRQ and adress, as far as I can see, and I've tried different ribbon cables and physical connectors.

Is there a difference between these old controller cards? WIll some of them not work with PS/2 mice?

Unfortunately, I don't have a real serial mouse to test with!

This is my old card, that works fine:

And these are the new cards, which I can't get working with my mouse:

Anyone got any idea?