INT 68 - APPC/PC - NETWORK DEVICE CONTROL - DETACH LOGICAL UNIT
        AH = 01h subfn 2200h
        DS:DX -> control block
Return: control block updated
SeeAlso: AH=01h/SF=2000h,AH=01h/SF=2100h,AH=01h/SF=2700h

Format of control block:
Offset  Size    Description
 00h 12 BYTEs   reserved
 0Ch    WORD    2200h (verb "Detach Logical Unit")
 0Eh  6 BYTEs   00h
 14h    DWORD   (big-endian) return code (see AH=01h/SF=1B00h)
 18h  8 BYTEs   (big-endian) logical unit ID
 20h    BYTE    00h

.