Question

I want to know whether it is possible in Delphi to read a CD as a raw Stream direct from the logical disk drive device “C:\”.

I hope I could use a TFileStream if I have already a valid file handle.

Answer 1

It is easiest to use THandleStream rather than TFileStream in my view. Like this:

procedure ReadFirstSector;
var
  Handle: THandle;
  Stream: THandleStream;
  Buffer: array [1..512] of Byte;
  b: Byte;
begin
  Handle := CreateFile('\\.\C:', GENERIC_READ,
    FILE_SHARE_READ or FILE_SHARE_WRITE, nil,
    OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
  if Handle=INVALID_HANDLE_VALUE then
    RaiseLastOSError;
  try
    Stream := THandleStream.Create(Handle);
    try
      Stream.ReadBuffer(Buffer, SizeOf(Buffer));
      for b in Buffer do
        Writeln(AnsiChar(b));
    finally
      Stream.Free;
    end;
  finally
    CloseHandle(Handle);
  end;
end;

Beware that when using raw disk access you have to read exactly multiples of sectors. The sectors on the disk I tested with are 512 bytes in size. I expect that CD disk sectors could very well be a different size.