Program to read the Partition Table Information of Drive C using biosdisk( ) function

 # include <stdlib.h>
 # include  <stdio.h>
 # include  <conio.h>
 # include   <bios.h>

 struct Partition
 {
    unsigned char ucBootable;
    unsigned char ucStartHead;
    unsigned int  uiStartCylinderSector;
    unsigned char ucTypeOfPartition;
    unsigned char ucEndHead;
    unsigned int  uiEndCylinderSector;
    unsigned long ulStartSector;
    unsigned long ulPartitionLength;
 };


 int main( )
 {
    unsigned char sBuffer[512]={NULL};

    clrscr( );
    textmode(BW80);

    biosdisk(2,0x80,0,0,1,1,sBuffer);

    if((_AH&0xFF)!=0x00)
    {
       switch(_AH)
       {
      case 0x01 : printf(\"Bad command\");
              break;

      case 0x02 : printf(\"Address mark not found\");
              break;

      case 0x03 : printf(\"Attempt to write to write-protected disk\");
              break;

      case 0x04 : printf(\"Sector not found\");
              break;

      case 0x05 : printf(\"Reset failed (hard disk)\");
              break;

      case 0x06 : printf(\"Disk changed since last operation\");
              break;

      case 0x07 : printf(\"Drive parameter activity failed\");
              break;

      case 0x08 : printf(\"Direct memory access (DMA) overrun\");
              break;

      case 0x09 : printf(\"Attempt to perform DMA across 64K boundary\");
              break;

      case 0x0A : printf(\"Bad sector detected\");
              break;

      case 0x0B : printf(\"Bad track detected\");
              break;

      case 0x0C : printf(\"Unsupported track\");
              break;

      case 0x10 : printf(\"Bad CRC/ECC on disk read\");
              break;

      case 0x11 : printf(\"CRC/ECC corrected data error\");
              break;

      case 0x20 : printf(\"Controller has failed\");
              break;

      case 0x40 : printf(\"Seek operation failed\");
              break;

      case 0x80 : printf(\"Attachment failed to respond\");
              break;

      case 0xAA : printf(\"Drive not ready (hard disk only)\");
              break;

      case 0xBB : printf(\"Undefined error occurred (hard disk only)\");
              break;

      case 0xCC : printf(\"Write fault occurred\");
              break;

      case 0xE0 : printf(\"Status error\");
              break;

      case 0xFF : printf(\"Sense operation failed\");
              break;

      default   : printf(\"Unknown Error\");
       }
    }

    else
    {
       struct Partition *ptrDriveC=(struct Partition*)&sBuffer[0x1BE];

       int iStartingCylinderHighByte=(ptrDriveC->uiStartCylinderSector>>8);
       int iStartingCylinderLowByte=((ptrDriveC->uiStartCylinderSector&0x00C0)<<2);
       int iStartingCylinder=(iStartingCylinderLowByte+iStartingCylinderHighByte);

       int iEndingCylinderHighByte=(ptrDriveC->uiEndCylinderSector>>8);
       int iEndingCylinderLowByte=((ptrDriveC->uiEndCylinderSector&0x00C0)<<2);
       int iEndingCylinder=(iEndingCylinderLowByte+iEndingCylinderHighByte);

       printf(\"* * * * * * * * * *  Partition Information  * * * * * * * * * *\\n\\n\");
       printf(\"Drive C: \");

       if(ptrDriveC->ucBootable==0x80)
      printf(\"Bootable\\n\");

       else
      printf(\"Not Bootable\\n\");

       printf(\"Start Head = %d\\n\",ptrDriveC->ucStartHead);
       printf(\"Starting Sector Number = %d\\n\",(ptrDriveC->uiStartCylinderSector&0x003F));
       printf(\"Starting Cylinder Number = %d\\n\",iStartingCylinder);

       printf(\"Partition Type = \");

       switch(ptrDriveC->ucTypeOfPartition)
       {
      case 0x00 : printf(\"Unused\\n\");
              break;

      case 0x01 : printf(\"12-Bit\\n\");
              break;

      case 0x02 : printf(\"Xenix\\n\");
              break;

      case 0x04 : printf(\"16-Bit\\n\");
              break;

      case 0x05 : printf(\"Extends\\n\");
              break;

      case 0x06 : printf(\"Huge\\n\");
              break;

      case 0x64 : printf(\"Novell\\n\");
              break;

      case 0x75 : printf(\"PCIX\\n\");
              break;

      case 0xDB : printf(\"CP/M\\n\");
              break;

      case 0xFF : printf(\"BBT\\n\");
              break;

      default   : printf(\"UnKnown\\n\");
              break;
       }

       printf(\"End Head = %d\\n\",ptrDriveC->ucEndHead);
       printf(\"Ending Sector Number = %d\\n\",(ptrDriveC->uiEndCylinderSector&0x003F));
       printf(\"Ending Cylinder Number = %d\\n\",iEndingCylinder);
       printf(\"Start Sector relative to Disk Begining = %ld\\n\",ptrDriveC->ulStartSector);
       printf(\"Partition Length = %ld\\n\",ptrDriveC->ulPartitionLength);

       printf(\"\\n* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\");
    }

    getch( );
    return 0;
 }