Title: Low Level Formatting of Drives
Question: How do you do a kind of low level format of a drive?
Answer:
This article follows on from "Creating and restoring images of drives?, http://www.delphi3000.com/articles/article_2812.asp".
I should clear up some miss-givings of CreateFile() in Disk Access - under Windows 9x (as far as I know), you can only use CreateFile() on non hard drive disks, though I do have a complex unit to get the job done under 9x if you want it - URL later.
Right, now this low level format is really simple, I'm assuming floppy disk for now:
procedure LowLevelFormat;
var
Disk: THandle;
Buffer: array [1..512] of Byte;
WroteOK: Boolean;
BufWrote: DWORD;
begin
Disk := CreateFile('\\.\A:',GENERIC_WRITE,FILE_SHARE_READ,nil,OPEN_EXISTING,0,0);
if Disk = 0 then
begin
ShowMessage('Error - Could not open device.');
Exit;
end;
FillChar(Buffer,SizeOf(Buffer),$00);
WroteOK := True;
BufWrote := 1;
while (WroteOK = True) and (BufWrote 0) do
begin
WroteOK := WriteFile(Disk,Buffer,SizeOf(Buffer),BufWrote,nil);
end;
CloseHandle(Disk);
end;
This method null's every byte on disk, removing boot sector, FAT tables and all!
Of course its fairly slow, you could try asynchranous null'ing of a number of sectors, or increasing the buffer size - experiment!
The URL to the unit is:
http://www.workshell.co.uk/dev/delphi/DejanMaksimovicAlfa32.zip