The keyboard device operates like the other Amiga devices.  To use it, you
must first open the keyboard device, then send I/O requests to it, and
then close it when finished.  See the "introduction to amiga system devices"
chapter for general information on device usage.

The I/O request used by the keyboard device is called IOStdReq.

    struct IOStdReq
    {
        struct  Message io_Message;
        struct  Device  *io_Device; /* device node pointer  */
        struct  Unit    *io_Unit;   /* unit (driver private)*/
        UWORD   io_Command;         /* device command */
        UBYTE   io_Flags;
        BYTE    io_Error;        /* error or warning num */
        ULONG   io_Actual;       /* actual number of bytes transferred */
        ULONG   io_Length;       /* requested number bytes transferred*/
        APTR    io_Data;         /* points to data area */
        ULONG   io_Offset;       /* offset for block structured devices */
    };

See the include file exec/io.h for the complete structure definition.

 opening the keyboard device 
 closing the keyboard device