INT 60 - FTP Packet Driver 1.09 - HIGH-PERF FUNC - ASYNCHRONOUS SEND PACKET
        AH = 0Bh
        DS:SI -> buffer
        CX = length of buffer
        ES:DI -> FAR function to call when buffer becomes available
Return: CF set on error
            DH = error code (0Bh,0Ch) (see AX=01FFh)
        CF clear if successful
Notes:  unlike function 04h, the buffer is not available for modification as
          soon as the call returns; the buffer may be queued by the driver and
          not processed until later
        this function has been dropped from v1.10+ of the specification and
          replaced by function 0Ch
SeeAlso: AH=0Ch"Packet Driver"

Completion function called with:
        AX = result
            00h copy OK
            nonzero error
        ES:DI -> buffer passed to INT 60/AH=0Bh call