INT 60 - FTP Packet Driver - BASIC FUNC - GET ADDRESS
        AH = 06h
        BX = handle (optional for v1.10+)
        ES:DI -> buffer
        CX = length
Return: CF set on error
            DH = error code (see AX=01FFh)
        CF clear if successful
            CX = length
Note:   copies the local net address associated with the handle into the buffer