diff --git a/src/test/X11/tetris/Readme.md b/src/test/X11/tetris/Readme.md
index 4e3d8884..17a7a327 100644
--- a/src/test/X11/tetris/Readme.md
+++ b/src/test/X11/tetris/Readme.md
@@ -1,4 +1,13 @@
+This is a game historycal source taken from http://web.archive.org/web/20050212180221/http://www.vis.inf.ethz.ch/~andy/Oberon.html
 
+It serves as an example of XYplane module usage.
+
+build by typing:
+
+make
+
+run by
+./Tetris
 
 
      * Start Tetris with Tetris.Start a~