'Benötigt werden: 2 Pictureboxen, 1 Textbox
Option Explicit
 
Private Sub Form_Activate()
  Dim SW%, SH%, Rad%, i%, Wnk!, XM%, YM%
  Me.ScaleMode = 3
  Me.WindowState = 2
  SW = Me.ScaleWidth
  SH = Me.ScaleHeight
  Picture2.ScaleMode = 3
  Picture2.BackColor = 0
  Picture2.AutoRedraw = True
  Picture2.Move SW / 2, 0, SW / 2, SH - 50
  Picture2.Cls
  With Picture1
  .ScaleMode = 3
  .BackColor = 0
  .AutoRedraw = True
  .Move 0, 0, SW / 2, SH - 50
  .Cls
  Rad = .ScaleWidth * 0.8
  For i = 0 To 99
    Wnk = 8 * Atn(1) / 100 * i
    XM = .ScaleWidth / 2
    YM = .ScaleHeight / 2
    Picture1.Line (XM, YM)-(XM + Rad * Sin(Wnk), YM + Rad * Cos(Wnk)), Rnd * _
      vbWhite
  Next i
  End With
  Text1.Move SW / 2, SH - 40
  Text1.MaxLength = 4
  Text1.Text = "2.5" 'Vergrößerungsfaktor
End Sub
 
Private Sub Text1_Change()
  Dim Fkt!, SW%, SH%
  Fkt = Val(Text1.Text)
  If Fkt <= 0 Then Exit Sub
  With Picture1
  SW = .ScaleWidth
  SH = .ScaleHeight
  Picture2.Cls
  Picture2.PaintPicture .Image, 0, 0, SW, SH, 0, 0, SW / Fkt, SH / Fkt
  End With
End Sub