CM_FLOPPY_DEVICE_DATA structure (wdm.h)

The CM_FLOPPY_DEVICE_DATA structure defines a device-type-specific data record that is stored in the \Registry\Machine\Hardware\Description tree for a floppy controller if the system can collect this information during the boot process.

Syntax

typedef struct _CM_FLOPPY_DEVICE_DATA {
  USHORT Version;
  USHORT Revision;
  CHAR   Size[8];
  ULONG  MaxDensity;
  ULONG  MountDensity;
  UCHAR  StepRateHeadUnloadTime;
  UCHAR  HeadLoadTime;
  UCHAR  MotorOffTime;
  UCHAR  SectorLengthCode;
  UCHAR  SectorPerTrack;
  UCHAR  ReadWriteGapLength;
  UCHAR  DataTransferLength;
  UCHAR  FormatGapLength;
  UCHAR  FormatFillCharacter;
  UCHAR  HeadSettleTime;
  UCHAR  MotorSettleTime;
  UCHAR  MaximumTrackValue;
  UCHAR  DataTransferRate;
} CM_FLOPPY_DEVICE_DATA, *PCM_FLOPPY_DEVICE_DATA;

Members

Version

The version number of this structure.

Revision

The revision of this structure.

Size[8]

The floppy disk density size.

MaxDensity

The maximum density.

MountDensity

The mount density.

StepRateHeadUnloadTime

The step rate head unload time in milliseconds.

HeadLoadTime

The head load time in milliseconds.

MotorOffTime

The motor off time in seconds.

SectorLengthCode

Indicates the sector size as an exponent in the formula ((2**code) * 128).

SectorPerTrack

The number of sectors per track.

ReadWriteGapLength

The read/write gap length, in bytes.

DataTransferLength

The data transfer length, in bytes, not including the synchronization field.

FormatGapLength

The format gap length, in bytes.

FormatFillCharacter

The format fill character.

HeadSettleTime

The head settle time in milliseconds.

MotorSettleTime

The motor settle time in milliseconds.

MaximumTrackValue

The maximum track number on the media. Track numbers are zero-based values.

DataTransferRate

The value written to the Datarate register before accessing the media.

Requirements

See also

CM_PARTIAL_RESOURCE_DESCRIPTOR

IoQueryDeviceDescription

IoReportResourceUsage