计算机的随机数是怎么产生的?

产生随机数是有算法的,还不止一种,下面给出一个：
Private Sub Command1_Click()
Dim flag As Boolean
Dim r(1000)
Dim d As String
Randomize '初始化随机种子
For i = 0 To 10 '出11个100以内的不重复数
Do
r(i) = Int(Rnd() * (100))
flag = True
For j = 0 To (i - 1)
If r(j) = r(i) Then
flag = False '如果用过了就退出.
Exit For
End If
Next j
Loop Until flag = True
d = d + ";" + Str(r(i))
Next i
Label1.Caption = d ’在label1中显示出来
End Su