INT 21,1F - Get Pointer to Current Drive Parameter Table

(Undocumented)

	AH = 1F
	DL = drive number (0=default, 1=A, ...)


	on return:
	AL = 00  DS:BX is pointer to drive parameter table  (DPT)
	     FF  drive does not exist
	DS:BX = pointer to drive parameter table (DPT) if AL=0


	- the format of the DPT varies between DOS versions
	- calls INT 21,32 with DL=00 for DOS version 2.x+