INT 2F U - PCIBM PC Tools v8.0 DRIVEMAP - CHECK IF MAPPED DRIVE
	AX = 9201h
	DL = drive number (01h = A:, etc.)
Return: AL = 92h if mapped drive
	AH may be destroyed (v8.0 DRIVEMAP returns AX=0000h if not mapped)
SeeAlso: AX=9204h,AX=920Bh