#include <dos.h>
#include <process.h>
#include <stdio.h>
#include <conio.h>

union REGS in,out;
struct SREGS sr;
unsigned char buf[512], sector[30], fat[2], clust_size, fat_cnt, index;
unsigned char count_partitions = 0, root_heads, root_sectors, root_cyls;
unsigned int i=0, j=1, p, partition_hand, partition_cyl, partition_sector, boot_flag, res_sect, sect_size, trk_sec, fat_type, fat_adress, head_cnt, a, b, c, d, e, g;
unsigned long starting_sector, num_sector, fat_size, root_catalogue_adress;
struct sec_cat {
unsigned char name[8];
unsigned char name_e[3];
unsigned char atr;
unsigned char rez[10];
unsigned int time;
unsigned int date;
unsigned int n_clust;
unsigned long size;
} *cat;
struct sec_cat sec[16];

void main()
{
clrscr();
in.h.ah = 2;
in.h.dl = 0x80;
in.h.dh = 0;
in.h.ch = 0;
in.h.cl = 1;
in.h.al = 1;
sr.es = FP_SEG(buf);
in.x.bx = FP_OFF(buf);
int86x(0x13,&in,&out,&sr);
if(out.x.cflag != 0 && out.h.ah != 0)
{
return;
}
for(i=0x1be;;i+=0x10){
if((int)buf[i] != 0x55 && (int)buf[i+1] != 0xaa) {
 count_partitions++;
 printf("Partitions: %d\n", count_partitions);
 }
 else
  break;
  }

  for(i=0x1be; i < 0x1ce; i+=0x10)
  {
  partition_hand = (int)buf[i+1];
  partition_sector = (int)buf[i+2]&0x3f;
  partition_cyl = (int)buf[i+3] + (((int)buf[i+2]&0xc0)<<2);
  boot_flag = (int)buf[i];
  starting_sector = *((unsigned long *)&buf[i+8]);
  num_sector = *((unsigned long *)&buf[i+12]);
  }
  in.h.ah = 2;
  in.h.dl = 0x80;
  in.h.dh = buf[0x1bf];
  in.x.cx = *((int *)&buf[0x1c0]);
  in.h.al = 1;
  sr.es = FP_SEG(sector);
  in.x.bx = FP_OFF(sector);
  int86x(0x13,&in,&out,&sr);
  if(out.x.cflag != 0 && out.h.ah != 0)
  {
  return;
  }
  sect_size = *((int *)&sector[0x0b]);
  clust_size = sector[0x0d];
  fat_size = *((unsigned long *)&sector[0x24]);
  trk_sec = *((int *)&sector[0x18]);
  head_cnt = *((int *)&sector[0x1A]);
  res_sect = *((int *)&sector[0x0e]);
  fat_cnt = sector[0x10];
  fat_adress = starting_sector + res_sect;
  root_catalogue_adress = fat_adress + fat_size * fat_cnt;
  printf("LBA root catalogue adress: %lu %u\n", root_catalogue_adress, fat_adress);
  root_cyls = root_catalogue_adress/(trk_sec*head_cnt);
  root_heads = (root_catalogue_adress%(trk_sec*head_cnt))/trk_sec;
  root_sectors = (root_catalogue_adress%(trk_sec*head_cnt))%trk_sec + 1;
  printf("CHS root catalogue adress: %u %u %u\n", root_cyls, root_heads, root_sectors);
  printf("Hold down some key to continue...\n");
  getch();
  in.h.ah = 2;
  in.h.dl = 0x80;
  in.h.dh = root_heads;
  in.h.ch = root_cyls;
  in.h.cl = root_sectors;
  in.h.al = 1;
  sr.es = FP_SEG(buf);
  in.x.bx = FP_OFF(buf);
  cat = (struct sec_cat *)&buf[0];
  int86x(0x13,&in,&out,&sr);
  if(out.x.cflag != 0 && out.h.ah != 0)
  {
  printf("OPERATION PORT READING WAS NOT SUCCESFULL! Hold down some key to quit...");
  getch();
  return;
  }
  a = 1;
  for(i = 0; i < 16; i++, a++)
  {
    if ((cat[i].atr>>4) == 1) {
      printf("Name: ");
      for (j = 0; j < 8; j++)
        printf("%c", cat[i].name[j]);
      break;
    }
  }
  printf("\n\nPress any key to exit...");
  getch();
  getch(); 
}