INT 15 - HUNTER 16 - GET DISKETTE PORTIBM PC Portable (uses same BIOS as XT)
	AX = 8400h
	BH = Drive (0: A:, 1: B:)
Return: AL = Port (0: COM1, >0: COM2)
Desc:	return the COM port used for the floppy drive
SeeAlso: AX=8401h