PORTIBM PC Portable (uses same BIOS as XT) 0120 - 3COM 3C509 Ethernet card - ID port (alternate address)
Note:	this port is present only on the 3C509, not on any other 3COM card
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0100h"3COM",PORTIBM PC Portable (uses same BIOS as XT) 0110h"3COM"