INT 6F - 10NET - LOCK SEMAPHORE, RETURN IMMEDIATELY
        AH = 0Bh
        AL = drive number or 0
        ES:SI = Ethernet address or 0
        DS:BX -> 31-byte ASCIZ semaphore name
Return: AL = status (see below)
Note:   same as INT 60/AH=12h
SeeAlso: AH=0Ch,INT 60/AH=12h

Values for status:
 00h    successful
 01h    semaphore currently locked
 02h    server not responding
 03h    invalid semaphore name
 04h    semaphore list is full
 05h    invalid drive ID
 06h    invalid Ethernet address
 07h    not logged in
 08h    write to network failed
 09h    semaphore already logged in this CPU
Index:  error codes;10-Net|10-Net;error codes

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