Write the information directly to sectors of the surface of floppy disk

/// Initialize the Disk System \\\

for(i=0; i<3; i++)
{
regs.h.ah = 0x00; /* Reset Disk System */
regs.h.dl = 0x00; /* Floppy Disk a: */

int86(0x13, &regs, &regs);
}

for(track=0;track<=79;track++)
{
for(head=0;head<=1;head++)
{
for(sector=1;sector<=18;sector++)
{
count =0;
while(count<512 )
{
fscanf(fp,"%c",&dbuf[count]);
count++;
}

dinfo.drive = 0x00; /* drive number for A: */
dinfo.head = head; /* disk head number */
dinfo.track = track; /* track number */
dinfo.sector = sector;/* sector number */
dinfo.nsectors = 1; /* sector count */
dinfo.buffer = dbuf; /* data buffer */

result= _bios_disk(_DISK_WRITE, &dinfo);

if ((result & 0xff00) == 0)
printf("Successful write on Track = %d, Head = %d,
Sector = %d.\n", track, head, sector);
else
printf("Cannot read drive A, status = 0x%02x\n",
result);

}
}
}
}

Comments on Program coding:

In the program coding given earlier, basically we are proceeding to perform the following tasks step by step:

• Character array filename[80] holds the path and file name of the file in which we stored the data of the surface of unreadable floppy temporarily.
• dinfo points to the diskinfo_t structure that contains the information of parameters required by the operation performed by the _bios_disk function.
• Initialize the disk system using the interrupt 13H (function 00h) where regs.h.ah = 0x00 points to the function 00 H and regs.h.dl = 0x00 is used for a: floppy. And int86(0x13, &regs, &regs) invokes MS-DOS interrupt service INT 13 H.
• As we are going to write the information directly to sectors of the surface of disk, The parameters of _bios_disk will be as follows:

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