INT 7C - SK-UPPS Data Link Interface API - DOWN DRIVER
        AX = 0001h
Return: AX = completion code (see below)
Note:   the DLI will refuse to unload if there are any protocols
          (see AX=0007h) or clients (see AX=0010h) active.
Index:  uninstall;SK-UPPS Data Link Interface

Completion codes:
 0000h SUCCESS
 0005h INVALID_MULTICAST
 0006h BUFFER_TOO_SMALL
 0007h NO_BUFFERS_LEFT
 0008h NO_RESOURCES_LEFT
 000Bh ILLEGAL_PROTOCOL_ID
 000Ch PROTOCOL_IN_USE
 000Dh NO_MULTICAST_ADDRESS
 000Fh PROTOCOLS_ACTIVE
 0010h CLIENTS_ACTIVE
 001Bh INVALID_MODE
 001Ch MODE_NOT_SUPPORTED
 FFFFh UNKNOWN_SERVICE

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