請問VB的一個小問題(編號：6831)

我想用VB程式來控制8255卡上面測試的LED燈能像跑馬燈一樣一個接一個的依序亮起但不知為何卻不行以下是我寫的程式望各位高手指點一二
宣告
Private Declare Function inp Lib "C:\Program Files\Microsoft Visual Studio\VB98\ Template\Forms\inpout32.dll" _ Alias "Inp32" (ByVal PortAddress As Integer) As Integer Private Declare Sub Out Lib "C:\Program Files\Microsoft Visual Studio\VB98\Templ ate\Forms\inpout32.dll" _ Alias "Out32" (ByVal PortAddress As Integer, ByVal Value As Integer)
COMMAND1
Private Sub Command1_Click() pa = &H200 Dim X X = 1 Do Out pa, X X = X * 2 Loop Until X ＞ 256 End Sub
FROM
Private Sub Form_Load() l pa = &H200 ctrl = &H203 Out &H203, &H80 End Sub