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.