NT系，Win 95 OSR2以降，Win 95初期版で場合分けしています。
NT系はとても簡単で，普通のファイル同様ReadFileで読み込めます。
9xでは結構面倒くさく，VWIN32 VxDを通じてDOS IOCTLファンクションを呼ぶということを行っています。
詳しくはここを参照してください。
[SDK32]OSR2上の Int 21 読み取り/書き込みトラックが失敗する
Win95 初期版で使えたファンクションがOSR2以降では使えないというバグがあるため，
OSR2以降で新しく用意された別のファンクションの呼出に切り替えています。
[ここをクリックすると内容が表示されます]
コード: 全て選択
#strict
Const CARRY_FLAG = 1
Const VWIN32_DIOC_DOS_INT25 = 2
Const VWIN32_DIOC_DOS_INT26 = 3
Const VWIN32_DIOC_DOS_DRIVEINFO = 6
Const INVALID_SET_FILE_POINTER = &HFFFFFFFF
Type DIOC_REGISTERS
reg_EBX As DWord
reg_EDX As DWord
reg_ECX As DWord
reg_EAX As DWord
reg_EDI As DWord
reg_ESI As DWord
reg_Flags As DWord
End Type
Type Align(1) DISKIO
dwStartSector As DWord ' 論理セクタ番号の開始番号
wSectors As Word ' セクタ数
dwBuffer As DWord ' 読み込み/書き込みバッファのアドレス
End Type
Declare Function DeviceIoControl Lib "Kernel32" (
hDevice As HANDLE,
dwIoControlCode As DWord,
lpInBuffer As VoidPtr,
nInBufferSize As DWord,
lpOutBuffer As VoidPtr,
nOutBufferSize As DWord,
lpBytesReturned As DWordPtr,
lpOverlapped As *OVERLAPPED) As Long
' GetClusterSize9x内部で呼んでいる関数
' これはMSのCでのサンプルの関数をほぼそのままABに移植しただけ。
' http://support.microsoft.com/?scid=kb;ja;174569
' NewReadSectors, ReadLogicalSectors
' 引数
' hDev vwin32のハンドル
' bDrive ドライブ番号(0=カレントドライブ, 1=Aドライブ, 2=B, 3=C 4=D, ……)
' dwStartSector 読み込み開始セクタ番号
' wSectors 読み込むセクタ数
' pSectBuff 読み込む先のバッファへのポインタ
Function NewReadSectors(hDev As HANDLE, bDrive As Byte, dwStartSector As DWord, wSectors As Word, pSectBuff As VoidPtr) As BOOL
Dim cb As DWord
Dim reg As DIOC_REGISTERS
Dim dio As DISKIO
With dio
.dwStartSector = dwStartSector
.wSectors = wSectors
.dwBuffer = pSectBuff As DWord
End With
With reg
.reg_EAX = &h7305 ' Ext_ABSDiskReadWrite
.reg_EBX = VarPtr(dio) As DWord
.reg_ECX = -1
.reg_EDX = bDrive ' Int 21h, fn 7305h ドライブ番号は 1 ベースです。
End With
If DeviceIoControl(hDev, VWIN32_DIOC_DOS_DRIVEINFO,
VarPtr(reg), Len(reg), VarPtr(reg), Len(reg), VarPtr(cb), 0) Then
' DeviceIoControl および読み取りが成功しているかどうか検証します。
NewReadSectors = (reg.reg_Flags And CARRY_FLAG) <> 0
End If
End Function
Function ReadLogicalSectors(hDev As HANDLE, bDrive As Byte,dwStartSector As DWord, wSectors As Word, pSectBuff As *Byte)
Dim cb As DWord
Dim reg As DIOC_REGISTERS
Dim dio As DISKIO
With dio
.dwStartSector = dwStartSector
.wSectors = wSectors
.dwBuffer = pSectBuff As DWord
End With
With reg
.reg_EAX = bDrive - 1 ' Int 25h ドライブ番号は 0 ベースです。
.reg_EBX = VarPtr(dio) As DWord
.reg_ECX = &hFFFF ' DISKIO 構造体を使用します。
End With
If DeviceIoControl(hDev, VWIN32_DIOC_DOS_INT25,
VarPtr (reg), Len (reg),
VarPtr (reg), Len (reg), VarPtr (cb), 0) <> FALSE Then
' DeviceIoControl および読み取りが成功しているかどうか検証します。
ReadLogicalSectors = (reg.reg_Flags And CARRY_FLAG) = 0
End If
End Function
Dim vi As OSVERSIONINFO
vi.dwOSVersionInfoSize = Len (vi)
GetVersionEx(vi)
Function IsWin95OSR2OrOver(ByRef vi As OSVERSIONINFO) As BOOL
With vi
If .dwPlatformId = VER_PLATFORM_WIN32_WINDOWS And _
.dwMajorVersion = 4 And _
(.dwMinorVersion >= 10 Or .szCSDVersion[0] = Asc("B") Or .szCSDVersion[0] = Asc("C")) Then
IsWin95OSR2OrOver = TRUE
Else
IsWin95OSR2OrOver = FALSE
End If
End With
End Function
Const SectorSize = 512
' ReadDriveSector - セクター単位読込
' driveLatter ドライブ文字
' startSector 読込を開始するセクタ番号（0から）
' sectors 読み込むセクタ数
' buf 読み込むバッファ
' 注意：セクタサイズは512バイトで決め打ちしてある。
Function ReadDriveSector(driveLatter As Byte, startSector As DWord, sectors As Word, buf As *Byte) As BOOL
If vi.dwPlatformId = VER_PLATFORM_WIN32_NT Then
Dim drive[6] As Byte
wsprintf(drive, "\\.\%c:", driveLatter)
Dim hDrive As HANDLE
hDrive = CreateFile(drive, GENERIC_READ, FILE_SHARE_READ, ByVal 0, OPEN_ALWAYS, 0, 0)
If hDrive <> INVALID_HANDLE_VALUE Then
If SetFilePointer(hDrive, startSector * SectorSize, 0, FILE_BEGIN) <> INVALID_SET_FILE_POINTER Then
Dim readSize As DWord
ReadDriveSector = ReadFile(hDrive, buf, sectors * SectorSize, VarPtr(readSize), ByVal 0)
End If
End If
CloseHandle(hDrive)
Else
Dim driveNum As Byte
driveNum = CharLower(driveLatter As ULONG_PTR As *Byte) As ULONG_PTR As Byte - Asc("a")
driveNum++
Dim hDevice As HANDLE
hDevice = CreateFile("\\.\vwin32", 0, 0, ByVal NULL, 0, FILE_FLAG_DELETE_ON_CLOSE, NULL)
If hDevice <> INVALID_HANDLE_VALUE Then
Dim ret As BOOL
If IsWin95OSR2OrOver(vi) Then
ReadDriveSector = NewReadSectors(hDevice, driveNum, startSector, sectors, buf)
Else
ReadDriveSector = ReadLogicalSectors(hDevice, driveNum, startSector, sectors, buf)
End If
CloseHandle(hDevice)
End If
End If
End Function
Dim buffer[ELM(SectorSize)] As Byte
ReadDriveSector(Asc("A"), 0, 1, buffer)
Dim hWrite As HANDLE
hWrite = CreateFile("H:\out.bin", GENERIC_WRITE, 0, ByVal 0, CREATE_ALWAYS, 0, 0)
If hWrite <> INVALID_HANDLE_VALUE Then
Dim writtenSize As DWord
WriteFile(hWrite, buffer, Len (buffer), VarPtr(writtenSize), ByVal 0)
CloseHandle(hWrite)
End If