c++ - How to Read particular sector of a disk using ATA command? -

i want read particular sector(mbr sector) of disk using ata commands in vc++. new vc++ facing problem when sending command disk using deviceiocontrol. providing code using read out sector using command read sector(s)(0x20).

  bool status = false;  pata_pass_through_ex patadata; dword datasize = sizeof(ata_pass_through_ex) + 512; byte buffer[sizeof(ata_pass_through_ex) + 512]; dword bytescopied = 0;      patadata = (ata_pass_through_ex*)buffer;      zeromemory(patadata,datasize); // clears buffer      patadata->length = sizeof(ata_pass_through_ex);     patadata->databufferoffset = sizeof(ata_pass_through_ex);     patadata->datatransferlength = 512;     patadata->timeoutvalue = 2;      patadata->currenttaskfile[1] = 0x01;     patadata->currenttaskfile[2] = 0x00;     patadata->currenttaskfile[3] = 0x00;     patadata->currenttaskfile[4] = 0x00;     patadata->ataflags =ata_flags_data_in;      patadata->currenttaskfile[6] = 0x20; // command read sector(s)(0x20)     /* sends command device, **hdevice** device handle*/     status = deviceiocontrol(hdevice, ioctl_ata_pass_through, patadata, datasize,buffer, datasize, &bytescopied, null ); 

i can't undersatnd what's wrong in code , missing here, not working. missing here ? if there problem parametres of pata_pass_through_ex structure tell how read first sector(mbr).

thanks guys. got solution. not assigning device handle in currenttaskfile.

patadata->currenttaskfile[5] = (uchar)hdevice; 

but identify_device(ech) command sending succesfully without this. don't know it's right or wrong working.