codigo fuente en visual basic

'variable que contiene la direccion base del puerto
Private DIR_PUERTO As Integer

'Declaracion de funciones
Private Declare Function GetPortBit Lib "IO.DLL" (ByVal Port As Integer, ByVal Bit As Byte) As Boolean
Private Declare Function IsDriverInstalled Lib "IO.DLL" () As Boolean
'Funciones que habilitan/deshabilitan bits del puerto.
Private Declare Function SetPortBit Lib "IO.DLL" (ByVal Port As Integer, ByVal Bit As Byte) As Boolean
Private Declare Function NotPortBit Lib "IO.DLL" (ByVal Port As Integer, ByVal Bit As Byte) As Boolean
Private Declare Function ClrPortBit Lib "IO.DLL" (ByVal Port As Integer, ByVal Bit As Byte) As Boolean

Private Sub Form_Load()
'Veo si cargo el driver
If IsDriverInstalled() = True Then
    DIR_PUERTO = &H378
Else
    MsgBox "Driver no instalado.", vbInformation + vbOKOnly + vbSystemModal, "Problemas!"
End
End If
End Sub

Private Sub LeerP_Click()
'Limpio el estado del puerto
For X = 0 To 7 Step 1
    aux = SetPortBit(DIR_PUERTO, X)
    aux = ClrPortBit(DIR_PUERTO, X)
Next

'Configuro el puerto paralelo como entrada
'poniendo el BIT 5 del port de control en 1
aux = SetPortBit(DIR_PUERTO + 2, 5)


 
'--- Ordeno la conversion A/D----
'selecciono el chip
'poniendo CS (Pin 1 del chip) a masa:C0=0 (Pin 1 del LPT)
aux = SetPortBit(DIR_PUERTO + 2, 0)



'Pongo WR (pin  3 del chip) bajo: C2=0 (pin 16 del LPT)
aux = SetPortBit(DIR_PUERTO + 2, 2)

'Espero al menos 100 ns
For X = 0 To 100000
Next


'Pongo WR (pin  3 del chip) en alto: C2=1 (pin 16 LPT)
aux = ClrPortBit(DIR_PUERTO + 2, 2)
'Leo y muestro Bits de control
For X = 0 To 7 Step 1
    If GetPortBit(DIR_PUERTO + 2, X) = True Then
        Text3(X).Text = CStr(1)
    Else
        Text3(X).Text = CStr(0)
    End If
Next

For X = 0 To 100000
Next



'Le doy tiempo a que INTR (pin 5 del chip) se ponga en alto
For X = 0 To 100000
Next


'Pongo RD (pin 2 del chip) en bajo: C3=1 (pin 1 LPT)
aux = ClrPortBit(DIR_PUERTO + 2, 3)

'Espera al menos 200 ns
For X = 0 To 100000
Next

'Leo los 8 bits del puerto
ValorD = 0
For X = 0 To 7 Step 1
    'Bits de datos
    If GetPortBit(DIR_PUERTO, X) = True Then
        Text1(X).Text = CStr(1)
        ValorD = ValorD + 2 ^ (7 - X)
    Else
        Text1(X).Text = CStr(0)
    End If
     
    'Bits de control
    If GetPortBit(DIR_PUERTO + 2, X) = True Then
        Text3(X).Text = CStr(1)
    Else
        Text3(X).Text = CStr(0)
    End If

Next X

'Calculo el valor porcentual, etc
ValorP = ValorD / 256 * 100
ValorV = ValorD / 256 * 5
'La siguiente linea calcula la temperatura a mostrar.
'Para calibrar lo que mide el sensor, podemos variar el
'valor que se resta al final (2.73).
ValorT = ValorV / 0.01 - 273
End Sub

Private Sub LimpiarP_Click()
'Limpio el estado del puerto
aux = ClrPortBit(DIR_PUERTO + 2, 5)

For X = 0 To 7 Step 1
    aux = SetPortBit(DIR_PUERTO, X)
    aux = ClrPortBit(DIR_PUERTO, X)
    aux = ClrPortBit(DIR_PUERTO + 2, X)
Next

'Leo los 8 bits del puerto
ValorD = 0
For X = 0 To 7 Step 1
    'Bits de datos
    If GetPortBit(DIR_PUERTO, X) = True Then
        Text1(X).Text = CStr(1)
        ValorD = ValorD + 2 ^ X
    Else
        Text1(X).Text = CStr(0)
    End If
    'Bits de control
    
    If GetPortBit(DIR_PUERTO + 2, X) = True Then
        Text3(X).Text = CStr(1)
    Else
    Text3(X).Text = CStr(0)
    End If
    

Next
End Sub

Private Sub Timer1_Timer()
Dim X As Integer
Dim aux As Integer

'acquiring different bits and there values in different registers in the parallel port
'For X = 0 To 7 Step 1
'If GetPortBit(DIR_PUERTO, X) = True Then
'Text1(X).Text = CStr(1)
'Else
'Text1(X).Text = CStr(0)
'End If

'If GetPortBit(DIR_PUERTO + 1, X) = True Then
'Text2(X).Text = CStr(1)
'Else
'Text2(X).Text = CStr(0)
'End If

'aux = SetPortBit(DIR_PUERTO + 2, 32)

'If GetPortBit(DIR_PUERTO + 2, X) = True Then
'Text3(X).Text = CStr(1)
'Else
'Text3(X).Text = CStr(0)
'End If



'Next X

End Sub



codigo fuente en vb.net

Option Strict Off
Option Explicit On
Friend Class Frm_Register_Analyzer
	Inherits System.Windows.Forms.Form
	'variable que contiene la direccion base del puerto
	Private DIR_PUERTO As Short
	
	'Declaracion de funciones
	Private Declare Function GetPortBit Lib "IO.DLL" (ByVal Port As Short, ByVal Bit As Byte) As Boolean
	Private Declare Function IsDriverInstalled Lib "IO.DLL" () As Boolean
	'Funciones que habilitan/deshabilitan bits del puerto.
	Private Declare Function SetPortBit Lib "IO.DLL" (ByVal Port As Short, ByVal Bit As Byte) As Boolean
	Private Declare Function NotPortBit Lib "IO.DLL" (ByVal Port As Short, ByVal Bit As Byte) As Boolean
	Private Declare Function ClrPortBit Lib "IO.DLL" (ByVal Port As Short, ByVal Bit As Byte) As Boolean
	Private Sub Frm_Register_Analyzer_Load(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles MyBase.Load
        'Veo si cargo el driver
        If IsDriverInstalled() = True Then
            DIR_PUERTO = &H378S
        Else
            MsgBox("Driver no instalado.", MsgBoxStyle.Information + MsgBoxStyle.OkOnly + MsgBoxStyle.SystemModal, "Problemas!")
            End
        End If
    End Sub
	
	Private Sub LeerP_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles LeerP.Click
		Dim aux As Object
		Dim X As Object
		'Limpio el estado del puerto
		For X = 0 To 7 Step 1
			
			aux = SetPortBit(DIR_PUERTO, X)
			
			aux = ClrPortBit(DIR_PUERTO, X)
		Next 
		
		'Configuro el puerto paralelo como entrada
		'poniendo el BIT 5 del port de control en 1
		
		aux = SetPortBit(DIR_PUERTO + 2, 5)
		
		
		
		'--- Ordeno la conversion A/D----
		'selecciono el chip
		'poniendo CS (Pin 1 del chip) a masa:C0=0 (Pin 1 del LPT)
		
		aux = SetPortBit(DIR_PUERTO + 2, 0)
		
		
		
		'Pongo WR (pin  3 del chip) bajo: C2=0 (pin 16 del LPT)
		
		aux = SetPortBit(DIR_PUERTO + 2, 2)
		
		'Espero al menos 100 ns
		For X = 0 To 100000
		Next 
		
		
		'Pongo WR (pin  3 del chip) en alto: C2=1 (pin 16 LPT)
		
		aux = ClrPortBit(DIR_PUERTO + 2, 2)
		'Leo y muestro Bits de control
		For X = 0 To 7 Step 1
			
			If GetPortBit(DIR_PUERTO + 2, X) = True Then
				Text3(X).Text = CStr(1)
			Else
				Text3(X).Text = CStr(0)
			End If
		Next 
		
		For X = 0 To 100000
		Next 
		
		
		
		'Le doy tiempo a que INTR (pin 5 del chip) se ponga en alto
		For X = 0 To 100000
		Next 
		
		
		'Pongo RD (pin 2 del chip) en bajo: C3=1 (pin 1 LPT)
		
		aux = ClrPortBit(DIR_PUERTO + 2, 3)
		
		'Espera al menos 200 ns
		For X = 0 To 100000
		Next 
		
		'Leo los 8 bits del puerto
        ValorD.Text = CStr(0)
		For X = 0 To 7 Step 1
			'Bits de datos
			
			If GetPortBit(DIR_PUERTO, X) = True Then
				Text1(X).Text = CStr(1)
				
				ValorD.Text = CStr(CDbl(ValorD.Text) + 2 ^ (7 - X))
			Else
				Text1(X).Text = CStr(0)
			End If

			'Bits de control
			
			If GetPortBit(DIR_PUERTO + 2, X) = True Then
				Text3(X).Text = CStr(1)
			Else
				Text3(X).Text = CStr(0)
			End If
			
		Next X
		
		'Calculo el valor porcentual, etc
		ValorP.Text = CStr(CDbl(ValorD.Text) / 256 * 100)
		ValorV.Text = CStr(CDbl(ValorD.Text) / 256 * 5)
		'La siguiente linea calcula la temperatura a mostrar.
		'Para calibrar lo que mide el sensor, podemos variar el
		'valor que se resta al final (2.73).
		ValorT.Text = CStr(CDbl(ValorV.Text) / 0.01 - 273)
	End Sub
	
	Private Sub LimpiarP_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles LimpiarP.Click
		Dim X As Object
		Dim aux As Object
		'Limpio el estado del puerto
		
		aux = ClrPortBit(DIR_PUERTO + 2, 5)
		
		For X = 0 To 7 Step 1
			
			aux = SetPortBit(DIR_PUERTO, X)
			
			aux = ClrPortBit(DIR_PUERTO, X)
			
			aux = ClrPortBit(DIR_PUERTO + 2, X)
		Next 
		
		'Leo los 8 bits del puerto
		ValorD.Text = CStr(0)
		For X = 0 To 7 Step 1
			'Bits de datos
			
			If GetPortBit(DIR_PUERTO, X) = True Then
				Text1(X).Text = CStr(1)
				
				ValorD.Text = CStr(CDbl(ValorD.Text) + 2 ^ X)
			Else
				Text1(X).Text = CStr(0)
			End If
			'Bits de control
			
			
			If GetPortBit(DIR_PUERTO + 2, X) = True Then
				Text3(X).Text = CStr(1)
			Else
				Text3(X).Text = CStr(0)
			End If
			
			
		Next 
	End Sub
	
	Private Sub Timer1_Timer()
        Dim X As Short
        Dim aux As Short
		
        'acquiring different bits and there values in different registers in the parallel port
        For X = 0 To 7 Step 1
            If GetPortBit(DIR_PUERTO, X) = True Then
                Text1(X).Text = CStr(1)
            Else
                Text1(X).Text = CStr(0)
            End If

            If GetPortBit(DIR_PUERTO + 1, X) = True Then
                Text2(X).Text = CStr(1)
            Else
                Text2(X).Text = CStr(0)
            End If

            aux = SetPortBit(DIR_PUERTO + 2, 32)

            If GetPortBit(DIR_PUERTO + 2, X) = True Then
                Text3(X).Text = CStr(1)
            Else
                Text3(X).Text = CStr(0)
            End If



        Next X

    End Sub
End Class