asked on

Int 21h Function 440Dh

if you look up help under Int 21h Function 440Dh Minor Code 46h(FAT32)

and make a working code out of it, that is all I need.

I have a structure

struct MID
{
WORD midInfoLevel;
DWORD midSerialNum;
char midVolLabel[11];
char midFileSysType[8];
};

and a puhbutton function
void CMyDlg::OnButtonRUN()
{
      // TODO: Add your control notification handler codehere
      MID* MediaID;
      MediaID->midInfoLevel = 0;
      __asm
      {

mov bx, 1 ;See below
mov ch, 48h ;See below
mov cl, 46h ;Set Media ID
mov dx, seg MediaID ;See below
mov ds, dx
mov dx, offset MediaID ;ds:dx points to MID structure
mov ax, 440Dh ;IOCTL for block device
int 21h

//jc error_handler ;carry set means error

      }
}

asm doesnot like mystructure, so try yourself

ASKER CERTIFIED SOLUTION

chensu

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has

ASKER

thank you for your help. I use winNT, and tried the code above
but could not get it working. I used exact same code except

"\\\\.\\vwin32" ( I used "\\\\.\\a:") and on my test button
void CFormatDlg::OnButtonTest()
{
      // TODO: Add your control notification handler code here
      MID mid;
      UINT nDrive = 0;
      if(GetMediaID(&mid, nDrive))
      {
            CString name;
            name = mid.midVolLabel;
            MessageBox(name);
      }
      else MessageBox("error");
}

but line
fResult = DeviceIoControl(hDevice, VWIN32_DIOC_DOS_IOCTL,
preg, sizeof(*preg), preg, sizeof(*preg), &cb, 0);

returns false ? can you tell ? is because of NT not win 95 ?
thanks

chensu

Yes, it is because of Windows NT. First, the Int 21h Function 440Dh Minor Code 46h(FAT32) is one of the Windows 95 features according to the documentation. And FAT32 is supported only by Windows 95 OEM Service Release 2 and later. Second, VWIN32.VXD is used in Windows 95.