The coding of the functions readabsolutesectors ( ) and writeabsolutesectors ( ) have been given next:
//// Function to read absolute sector(s) \\\\
int readabsolutesectors ( int drive,
unsigned long sectornumber,
int numofsectors,
void *buffer )
{
union REGS i, o ;
struct SREGS s ;
struct diskaddrpacket pp ;
pp.packetsize = 16 ; /* packet size = 10H */
pp.reserved = 0 ; /* Reserved = 0 */
pp.blockcount = numofsectors ; /* Number of sectors
to read */
/* for Data buffer */
pp.bufferaddress = (char far*) MK_FP ( FP_SEG((void
far*)buffer), FP_OFF((void far*)buffer));
pp.blocknumber[0] = sectornumber ; /* Sector number
to read */
pp.blocknumber[1] = 0 ; /* Block number */
i.h.ah = 0x42 ; /* Function Number*/
i.h.dl = drive ; /* Physical Drive Number */
i.x.si = FP_OFF ( (void far*)&pp ) ; /* ds:si for
buffer Parameters */
s.ds = FP_SEG ( (void far*)&pp ) ; /* ds:si for
buffer Parameters */
/* Invoke the specified Function of INT 13H with
segment register values */
int86x ( 0x13, &i, &o, &s ) ;
if ( o.x.cflag==1)
return 0 ; /*failure */
else
return 1 ; /* success */
}
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