Int 21 - Function 44h - I/O Control for Devices (IOCTL) Get or Set Device Information

	 
Sub-Function	  Description
----------------- -------------------------------------------------------------
Int\21f\44sf\00 Get Device Information (from DX)
Int\21f\44sf\01 Set Device Information (DH must be zero for this call)
Int\21f\44sf\02 Read CX bytes to device in DS:DX from BX control chan
Int\21f\44sf\03 Write Device Control String
Int\21f\44sf\04 Read From Block Device (drive number in BL)
Int\21f\44sf\05 Write to Block Device  (drive number in BL)
Int\21f\44sf\06 Get Input Handle Status
Int\21f\44sf\07 Get Output Handle Status
Int\21f\44sf\08 Removable Media Bit			       (DOS 3.x+)
Int\21f\44sf\09 Test whether Local or Network Device in BL   (DOS 3.x+)
Int\21f\44sf\0A Is Handle in BX Local or Remote?	       (DOS 3.x+)
Int\21f\44sf\0B Change Sharing Retry Count to DX (default=3),(DOS 3.x+)
Int\21f\44sf\0C General device IOCTL			       (DOS 3.3 [3.2?])
Int\21f\44sf\0D Block Device Request			       (DOS 3.3+)
Int\21f\44sf\0E Get Logical Device			       (DOS 3.3+)
Int\21f\44sf\0F Set Logical Device			       (DOS 3.3+)

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