This code demonstrates how to read & write raw data from a floppy disk (or other removable disk).  The CreateFile API call can also be used to open other Win32 devices such as COM ports.

This code requires the following imports:

Imports System.Management
Imports System.IO

The first thing we do is to declare the API calls we'll be using.

#Region "API"
    Private Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, _
                                                                                                                                    ByVal dwDesiredAccess As Int32, _
                                                                                                                                    ByVal dwShareMode As Int32, _
                                                                                                                                    ByVal lpSecurityAttributes As IntPtr, _
                                                                                                                                    ByVal dwCreationDistribution As Int32, _
                                                                                                                                    ByVal dwFlagsAndAttributes As Int32, _
                                                                                                                                    ByVal hTemplateFile As Int32) As IntPtr

    Private Declare Function ReadFile Lib "kernel32" (ByVal hFile As IntPtr, _
                                                                                            ByVal lpBuffer As Byte(), _
                                                                                            ByVal nNumberOfBytesToRead As Int32, _
                                                                                            ByRef lpNumberOfBytesRead As Int32, _
                                                                                            ByVal lpOverlapped As IntPtr) As Int32

    Private Declare Function WriteFile Lib "kernel32" (ByVal hFile As IntPtr, _
                                                                                             ByVal lpBuffer As Byte(), _
                                                                                             ByVal nNumberOfBytesToWrite As Int32, _
                                                                                             ByRef lpNumberOfBytesWritten As Int32, _
                                                                                             ByVal lpOverlapped As IntPtr) As Int32

    Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As IntPtr) As Long

    Const GENERIC_READ As Int32 = &H80000000
    Const GENERIC_WRITE As Int32 = &H40000000
    Const OPEN_EXISTING As Int32 = 3
    Const FILE_SHARE_READ As Int32 = &H1
    Const FILE_SHARE_WRITE As Int32 = &H2
    Const FILE_ATTRIBUTE_NORMAL As Int32 = &H80
    Const FILE_FLAG_NO_BUFFERING As Int32 = &H20000000
#End Region

Next, we want to find the removable drives (floppies) on our system.

Private Sub DetectFloppyDrives()
    Dim diskClass As New ManagementClass("Win32_LogicalDisk")
    Dim disks As ManagementObjectCollection = diskClass.GetInstances()
    Dim disk As ManagementObject
    For Each disk In disks
        If disk("drivetype").ToString = "2" Then cboFloppy.Items.Add(disk("deviceid"))
    Next
    If cboFloppy.Items.Count = 0 Then
        btnCreate.Enabled = False
        MsgBox("This program cannot function without a floppy drive.", MsgBoxStyle.Information)
        Exit Sub
    End If
    cboFloppy.SelectedIndex = 0 'select first item in list
End Sub

Then, we want to create our Image Subroutines (CreateImage & CreateDisk)

Private Sub CreateImage()
    Dim ImageName As String
    With SaveFileDialog1
        .DefaultExt = ".fss"
        .Filter = "Floppy Snapshots (.fss)|*.fss|DD Disk Images (.img)|*.img"
        .FilterIndex = 0
        .Title = "Save Floppy Snapshot"
        .ShowDialog(Me)
        ImageName = .FileName
        If ImageName = "" Then Exit Sub
    End With
    btnCreate.Enabled = False
    'read in increments of 18432 (80 tracks)
    Dim buf(18432) As Byte
    Dim fh As IntPtr = CreateFile("\\.\" & cboFloppy.Text, _
                                                                       GENERIC_READ, _
                                                                       FILE_SHARE_READ, _
                                                                       IntPtr.Zero, _
                                                                       OPEN_EXISTING, _
                                                                       FILE_ATTRIBUTE_NORMAL Or FILE_FLAG_NO_BUFFERING, _
                                                                        0)
    Dim sw As New FileStream(ImageName, FileMode.Create)
    With ProgressBar1
        .Minimum = 0
        .Maximum = 80
        .Value = 0
    End With
    For i As Integer = 1 To 80
        Dim y As Int32
        Dim x As Int32 = ReadFile(fh, buf, 18432, y, IntPtr.Zero)
        If x = 1 Then
            sw.Write(buf, 0, 18432)
            ProgressBar1.Value = i
        Else
            MsgBox("Bad Disk or No Disk in Drive.", MsgBoxStyle.Critical)
        Exit For
    End If
        Application.DoEvents()
    Next
    CloseHandle(fh)
    sw.Close()
    ProgressBar1.Value = 0
    btnCreate.Enabled = True
End Sub
 

Private Sub CreateDisk()
    Dim ImageName As String
    With OpenFileDialog1
        .FileName = ""
        .DefaultExt = ".fss"
        .Filter = "Floppy Snapshots (.fss)|*.fss|DD Disk Images (.img)|*.img"
        .FilterIndex = 0
        .Title = "Choose Image File"
        .ShowDialog(Me)
        ImageName = .FileName
        If ImageName = "" Then Exit Sub
    End With
    btnCreate.Enabled = False
    'write in increments of 18432 (80 tracks)
    Dim buf(18432) As Byte
    Dim fh As IntPtr = CreateFile("\\.\" & cboFloppy.Text, _
                                                                       GENERIC_WRITE, _
                                                                       FILE_SHARE_WRITE, _
                                                                       IntPtr.Zero, _
                                                                       OPEN_EXISTING, _
                                                                       FILE_ATTRIBUTE_NORMAL Or FILE_FLAG_NO_BUFFERING, _
                                                                       0)
    Dim sr As New FileStream(ImageName, FileMode.Open)
    With ProgressBar1
        .Minimum = 0
        .Maximum = 80
        .Value = 0
    End With
    For i As Integer = 1 To 80
        sr.Read(buf, 0, 18432)
        Dim y As Int32
        Dim x As Int32 = WriteFile(fh, buf, 18432, y, IntPtr.Zero)
        If x = 1 Then
            ProgressBar1.Value = i
        Else
            MsgBox("Bad Disk or No Disk in Drive.", MsgBoxStyle.Critical)
            Exit For
        End If
        Application.DoEvents()
    Next
    CloseHandle(fh)
    sr.Close()
    ProgressBar1.Value = 0
    btnCreate.Enabled = True
End Sub

This will get the job done.  How you design your interface & call the routines is up to you. My finished program looks like this:

Download the VB2005 Project