struct StdIOReq

#include <exec/io.h>

struct StdIOReq
{
    struct Message io_Message;
    struct Device *io_Device; /* Filled in by OpenDevice */
    struct Unit *io_Unit; /* Device-private data */
    UWORD io_Command; /* What to do */
    UWORD io_Error;
    LONG io_Actual;  /* Actual written/read data */
    LONG io_Length;  /* Data to write/read */
    LONG io_Data;    /* Pointer to data */
    ULONG io_Offset;  /* Block number for block-oriented devices */
};

#define CMD_INVALID     0
#define CMD_RESET       1
#define CMD_READ        2
#define CMD_WRITE       3
#define CMD_UPDATE      4
#define CMD_CLEAR       5
#define CMD_STOP        6
#define CMD_START       7
#define CMD_FLUSH       8
#define CMD_SETPARAMS   9
#define CMD_WAITFORCHAR 10