Send Broadcast Datagram Command (Net Bios, 22h)

        This command is used to send a broadcast message. The Net Bios
        does not necessarily detect whether the message was successfully
        delivered. The NUM field associates the datagram with a local
        name. BUFADR and BUFLEN contain the address and length of the
        message. Maximum allowable length is 512 bytes.

        Each SEND BROADCAST satisfies all outstanding RECEIVE BROADCAST
        commands on the network.