INT 2F - DBLSPACE.BIN - "DSGetEntryPoints" - GET DEVICE DRIVER ENTRY POINTS
	AX = 4A11h
	BX = 0003h
	CL = drive number (0=A:) of compressed drive
Return: CL = FFh on error (not compressed drive)
	CL <> FFh driver unit number of host drive
	    ES:SI -> device driver's strategy routine
	    ES:DI -> device driver's interrupt routine
	BX destroyed
Note:	in conjunction with subfunction 0004h, this call allows disk caches
	  like SMARTDRV to apply a device driver wrapper to DoubleSpaced
	  drives just like SMARTDRV applies to regular block devices
SeeAlso: AX=4A10h/BX=0007h,AX=4A11h/BX=0000h,AX=4A11h/BX=0004h