Use SendMessage function and WM_VSCROLL message with SB_PAGEDOWN or SB_PAGEUP parameters.
procedure TForm1.Button2Click(Sender: TObject); begin SendMessage(Memo1.Handle, WM_VSCROLL, SB_PAGEUP, 0); end; procedure TForm1.Button1Click(Sender: TObject); begin SendMessage(Memo1.Handle, WM_VSCROLL, SB_PAGEDOWN, 0); end;