_SENDCMDINPARAMS = packed record
    cBufferSize: DWORD;   // Buffer size in bytes
    irDriveRegs: IDEREGS; // Structure with drive register values.
    bDriveNumber: BYTE;   // Physical drive number to send
                          // command to (0,1,2,3).
    bReserved: array [0..2] of BYTE;   // Reserved for future expansion.
    dwReserved: array [0..3] of DWORD; // For future use.
    bBuffer: array [0..0] of BYTE;     // Input buffer.
  end;
  ...
  _IDEREGS = packed record
    bFeaturesReg: BYTE;     // Used for specifying SMART "commands".
    bSectorCountReg: BYTE;  // IDE sector count register
    bSectorNumberReg: BYTE; // IDE sector number register
    bCylLowReg: BYTE;       // IDE low order cylinder value
    bCylHighReg: BYTE;      // IDE high order cylinder value
    bDriveHeadReg: BYTE;    // IDE drive/head register
    bCommandReg: BYTE;      // Actual IDE command.
    bReserved: BYTE;        // reserved for future use.  Must be zero.
  end;