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The Data Types representing several parameters of the disk have the following meanings:
Data Type |
Size in Bytes |
Description |
unsigned int size |
2 Bytes |
Size of Buffer |
unsigned int flags |
2 Bytes |
Information Flags |
unsigned long cyl |
4 Bytes |
Number of Physical Cylinders on Drive |
unsigned long heads |
4 Bytes |
Number of Physical Heads on Drive |
unsigned long spt |
4 Bytes |
Number of Physical Sectors Per Track |
unsigned long sectors[2] |
8 Bytes |
Total Number of Sectors on Drive |
unsigned int bps |
2 Bytes |
Bytes Per Sector |
- The structure diskaddrpacket is used by the functions readabsolutesectors and writeabsolutesectors. The format of disk address packet has been given in the following table:
Data Type |
Size in Bytes |
Description |
char packetsize |
1 Byte |
Size of Packet, generally 10H |
char reserved |
1 Byte |
Reserved (0) |
int blockcount |
2 Bytes |
Number of Blocks to Transfer |
char far *bufferaddress |
4 Bytes |
address to Transfer Buffer |
unsigned long blocknumber[2] |
4 Bytes |
Starting Absolute Block Number |
- The getdrivegeometry function is used to get the parameters of specified Drive. The Function getdrivegeometry uses function number 0x48 of INT 13H Extensions.
The meaning of parameters has been described in the table given next:
Parameter |
What it means |
i.h.ah = 0x48 |
Function Number 0x48 of INT 13H Extensions |
i.h.dl = drive |
Drive Number |
i.x.si = FP_OFF ( (void far*)&g ) |
ds:si address to buffer for drive parameters as discussed earlier |
s.ds = FP_SEG ( (void far*)&g ) |
ds:si address to buffer for drive parameters as discussed earlier |
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