BIOSPARAMETERBLOCK

BIOS Parameter Block.

Type

USHORT   usBytesPerSector;
BYTE     bSectorsPerCluster;
USHORT   usReservedSectors;
BYTE     cFATs;
USHORT   cRootEntries;
USHORT   cSectors;
BYTE     bMedia;
USHORT   usSectorsPerFAT;
USHORT   usSectorsPerTrack;
USHORT   cHeads;
ULONG    cHiddenSectors;
ULONG    cLargeSectors;
BYTE     abReserved[6];
USHORT   cCylinders;
BYTE     bDeviceType;
USHORT   fsDeviceAttr;

C Declaration Method

typedef struct

Fields

usBytesPerSector   Number of bytes per sector.
bSectorsPerCluster Number of sectors per cluster.
usReservedSectors  Number of reserved sectors.
cFATs              Number of FATs.
cRootEntries       Number of root directory entries.
cSectors           Number of sectors.
bMedia             Media descriptor.
usSectorsPerFAT    Number of secctors per FAT.
usSectorsPerTrack  Number of sectors per track.
cHeads             Number of heads.
cHiddenSectors     Number of hidden sectors.
cLargeSectors      Number of large sectors.
abReserved[6]      Reserved.
cCylinders         Number of cylinders defined for the physical device.
bDeviceType        Physical layout of the specified device.

                   0   48 TPI low-density diskette drive 
                   1   96 TPI high-density diskette drive 
                   2   Small (3.5-inch) 720KB drive 
                   3   8-inch single-density diskette drive 
                   4   8-inch double-density diskette drive 
                   5   Fixed disk 
                   6   Tape drive 
                   7   Other (includes 1.44MB 3.5-inch diskette drive) 
                   8   R/W optical disk 
                   9   3.5-inch 4.0MB diskette drive (2.88MB formatted)

fsDeviceAttr       A bit field that returns flag information about the
                   specified drive.

                   Bit 0  Removable Media flag.

                   0   Media is removable. 
                   1   Media cannot be removed.

                   Bit 1  Changeline flag.

                   0   The physical device driver returns the value 0, Unsure
                       if media has changed, from the Media Check function. 
                   1   Device support determines that the media was removed 
                       since the last I/O operation.