asked on

Read sector(s) from floppy

Hi, I want to read a floppy sector-by-sector.

E.G.
...
asm
mov ah, 02h //function 2 : read sector
mov dl, 00h //first drive A:
mov dh, 00h //head 0
mov ch, 00h //track 0
mov cl, 01h //sector 1
mov al, 01h //read 1 sector
mov es, SEG buff //segment address of buffer
mov bx, OFFSET buff //offset address of buffer
int 13h //read sector with interrupt 13
end;
...

But, "SEG" is not available in Delphi2,
so what do I do then???

Madshi

This won't work with 32bit windows. You'll have to use CreateFile and DeviceIOControl instead. Please look in the win32 help file for a topic called "Calling DeviceIOControl on Windows 95" or "Using DeviceIOControl...".

Sorry, have no sources available at this moment... :-(

Regards, Madshi.

inthe

Hello
Here is a demo from dejanews
It shows how to change the serial numberof a floppy disk using deviceiocontrol. it may be of assistance if only to help you understand how to use deviceiocontrol

InThe

USE IT AT YOUR OWN RISK!!!

unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics,
Controls, Forms, Dialogs, StdCtrls, ComCtrls;type TForm1 = class(TForm)
Button1: TButton; procedure Button1Click(Sender: TObject); private
{ Private-Deklarationen } public { Public-Deklarationen } end;var
Form1: TForm1;const VWin32_DIOC_DOS_Int25 = 2; // direkter Lesezugriff
// direct read access
VWin32_DIOC_DOS_Int26 = 3; // direkter Schreibzugriff
// direct write accesstype
TDevIoCtl_Reg = packed Record Reg_EBX : DWord; Reg_EDX : DWord;
Reg_ECX : DWord; Reg_EAX : DWord; Reg_EDI : DWord; Reg_ESI : DWord;
Reg_Flags : DWord;end;type TDiskIO = packed record StartSektor : DWord;
AnzahlSektoren : Word; PBuffer : DWord;end;implementation{$R *.DFM}
// Bootsektor lesen, Seriennummer ändern und// Bootsektor zurückschreiben
// read boot sector, change serial number, and// write boot sector back
procedure TForm1.Button1Click(Sender: TObject);var DevIoHandle : THandle;
BytesReturned : DWord; Reg : TDevIoCtl_Reg;
DiskIO : TDiskIO;
DatenBuffer : Array [0..511] of Byte; // = 512 Bytes
// Die Sektorgröße kann man mit GetDiskFreeSpace ermitteln
// (normalerweise = 512 Bytes, bei CD-ROMs = 2048 Bytes).
// The size of one sector can be found out with GetDiskFreeSpace
// (normaly = 512 bytes, CD-ROMs = 2048 bytes).begin
// DiskIO und Reg initialisieren // initialize DiskIO and Reg with DiskIO do
begin StartSektor := 0; // ab Sektor 0 / from sector 0
AnzahlSektoren := 1; // 1 Sektor lesen / read 1 sector
PBuffer := DWord(@DatenBuffer); end; with Reg do begin
reg_EAX := 0; // Laufwerk: / drive: 0 = A, 1 = B usw.
reg_EBX := DWord(@DiskIO);
reg_ECX := $FFFF; // benutze / use DiskIO end;
// Handle für DeviceIoControl holen. // retrieve handle for DeviceIoControl
DevIoHandle := CreateFile( '\\.\vwin32',
Generic_Read,
File_Share_Read or File_Share_Write, nil,
Open_Existing, File_Attribute_Normal,
0); // Nur weiter, wenn Handle gültig ist.
// only proceed, if handle is valid
if DevIoHandle <> Invalid_Handle_Value then begin
// direkter Lesezugriff // direct read access
DeviceIoControl(DevIoHandle, VWin32_DIOC_DOS_Int25,
@Reg, SizeOf(Reg),
@Reg, SizeOf(Reg),
BytesReturned, nil);
// neue Seriennummer = $12345678 // new serial number = $12345678
DatenBuffer[39] := $78; DatenBuffer[40] := $56;
DatenBuffer[41] := $34; DatenBuffer[42] := $12;
// direkter Schreibzugriff // direct write access
DeviceIoControl(DevIoHandle, VWin32_DIOC_DOS_Int26,
@Reg, SizeOf(Reg),
@Reg, SizeOf(Reg),
BytesReturned, nil);
// Handle freigeben // release handle CloseHandle(DevIoHandle);
end;end;end.

inthe

ps..sorry that's such a bloody mess:-)

skatan_187

I am looking for a function that reads a disk until there is an error and then give the sector
as result .. So actually I am looking for the same stuff you are looking for. If I find something
i'll inform you about it ;-)

SkAtAn

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dwwang

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dwwang

Hi, any progress?