请问硬盘序列号是个什么东东，怎么产生的？(36分)

不少软件都用硬盘序列号来生成机器码，那么请问硬盘序列号是个什么东东，怎么产生的？在多台同一品牌硬盘中重复的机率高吗？会不会有没有序列号的硬盘？
在网上找到一段取硬盘序列号的代码，怎么在多台机器上得到的都是一样的值？


获取 IDE 硬盘序列号
function GetIdeSerialNumber() : PChar; stdcall;
const
IDENTIFY_BUFFER_SIZE = 512;
type
TIDERegs = packed record
bFeaturesReg: BYTE; // Used for specifying SMART "commands".
bSectorCountReg: BYTE; // IDE sector count register
bSectorNumberReg: BYTE; // IDE sector number register
bCylLowReg: BYTE; // IDE low order cylinder value
bCylHighReg: BYTE; // IDE high order cylinder value
bDriveHeadReg: BYTE; // IDE drive/head register
bCommandReg: BYTE; // Actual IDE command.
bReserved: BYTE; // reserved for future use. Must be zero.
end;
TSendCmdInParams = packed record
// Buffer size in bytes
cBufferSize: DWORD;
// Structure with drive register values.
irDriveRegs: TIDERegs;
// Physical drive number to send command to (0,1,2,3).
bDriveNumber: BYTE;
bReserved: array[0..2] of Byte;
dwReserved: array[0..3] of DWORD;
bBuffer: array[0..0] of Byte; // Input buffer.
end;
TIdSector = packed record
wGenConfig: Word;
wNumCyls: Word;
wReserved: Word;
wNumHeads: Word;
wBytesPerTrack: Word;
wBytesPerSector: Word;
wSectorsPerTrack: Word;
wVendorUnique: array[0..2] of Word;
sSerialNumber: array[0..19] of CHAR;
wBufferType: Word;
wBufferSize: Word;
wECCSize: Word;
sFirmwareRev: array[0..7] of Char;
sModelNumber: array[0..39] of Char;
wMoreVendorUnique: Word;
wDoubleWordIO: Word;
wCapabilities: Word;
wReserved1: Word;
wPIOTiming: Word;
wDMATiming: Word;
wBS: Word;
wNumCurrentCyls: Word;
wNumCurrentHeads: Word;
wNumCurrentSectorsPerTrack: Word;
ulCurrentSectorCapacity: DWORD;
wMultSectorStuff: Word;
ulTotalAddressableSectors: DWORD;
wSingleWordDMA: Word;
wMultiWordDMA: Word;
bReserved: array[0..127] of BYTE;
end;
PIdSector = ^TIdSector;
TDriverStatus = packed record
// 驱动器返回的错误代码，无错则返回0
bDriverError: Byte;
// IDE出错寄存器的内容，只有当bDriverError 为 SMART_IDE_ERROR 时有效
bIDEStatus: Byte;
bReserved: array[0..1] of Byte;
dwReserved: array[0..1] of DWORD;
end;
TSendCmdOutParams = packed record
// bBuffer的大小
cBufferSize: DWORD;
// 驱动器状态
DriverStatus: TDriverStatus;
// 用于保存从驱动器读出的数据的缓冲区，实际长度由cBufferSize决定
bBuffer: array[0..0] of BYTE;
end;
var
hDevice : THandle;
cbBytesReturned : DWORD;
SCIP : TSendCmdInParams;
aIdOutCmd : array[0..(SizeOf(TSendCmdOutParams) + IDENTIFY_BUFFER_SIZE - 1) - 1] of Byte;
IdOutCmd : TSendCmdOutParams absolute aIdOutCmd;
procedure ChangeByteOrder(var Data; Size: Integer);
var
ptr : PChar;
i : Integer;
c : Char;
begin
ptr := @Data;
for I := 0 to (Size shr 1) - 1 do
begin
c := ptr^;
ptr^ := (ptr + 1)^;
(ptr + 1)^ := c;
Inc(ptr, 2);
end;
end;
begin
Result := ''; // 如果出错则返回空串
if SysUtils.Win32Platform = VER_PLATFORM_WIN32_NT then // Windows NT, Windows 2000
begin
// 提示! 改变名称可适用于其它驱动器，如第二个驱动器： '//./PhysicalDrive1/'
hDevice := CreateFile('//./PhysicalDrive0', GENERIC_READ or GENERIC_WRITE,
FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
end
else // Version Windows 95 OSR2, Windows 98
hDevice := CreateFile('//./SMARTVSD', 0, 0, nil, CREATE_NEW, 0, 0);
if hDevice = INVALID_HANDLE_VALUE then Exit;
try
FillChar(SCIP, SizeOf(TSendCmdInParams) - 1, #0);
FillChar(aIdOutCmd, SizeOf(aIdOutCmd), #0);
cbBytesReturned := 0;
// Set up data structures for IDENTIFY command.
with SCIP do
begin
cBufferSize := IDENTIFY_BUFFER_SIZE;
// bDriveNumber := 0;
with irDriveRegs do
begin
bSectorCountReg := 1;
bSectorNumberReg := 1;
// if Win32Platform=VER_PLATFORM_WIN32_NT then bDriveHeadReg := $A0
// else bDriveHeadReg := $A0 or ((bDriveNum and 1) shl 4);
bDriveHeadReg := $A0;
bCommandReg := $EC;
end;
end;
if not DeviceIoControl(hDevice, $0007C088, @SCIP, SizeOf(TSendCmdInParams) - 1,
@aIdOutCmd, SizeOf(aIdOutCmd), cbBytesReturned, nil) then Exit;
finally
CloseHandle(hDevice);
end;
with PIdSector(@IdOutCmd.bBuffer)^ do
begin
ChangeByteOrder(sSerialNumber, SizeOf(sSerialNumber));
(Pchar(@sSerialNumber) + SizeOf(sSerialNumber))^ := #0;
Result := Pchar(@sSerialNumber);
end;
end;

硬盘身份证,在工厂里产生的

硬盘序列号是生产厂家给硬盘编制制作的编号，是唯一的。但个别厂家的硬盘没有序列号，当然测出来的就都一样了。上面那段代码我测试过，可用。

这段代码正确不正确暂时不知道，你可以在同一台机器上用DOS下的工具读一下序列号看一看。

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