At IPP 28 2008 in Prague the participants received a cardboard drawing of this puzzle. I enjoyed making a few, this is the last one I have. An additional slide holder with the history of the tower
Copy produced by puzzle design Ton Delsing. Old Puzzle. The following text is printed on the back of the box.With the 9 pieces a large square or other figuresis to be formed in such a way that the same colour shal not occur more then once in any row horizontal or vertical (in the square also diagonal) This must be done for each symbol..Material . Cardboard pieces
Place the pieces in the frame, Place the black piece with the holes on it. You should now see the 0 and 9. (start position). There are several ways to do this, There is only 1 good to slide to the numbers 1 to 4. Then slide to the numbers 5 to 8, Then slide the 1 at the top left and the 8 at the bottom right, Place the black piece on it so that you only see the 1 and 8. (end position)Material acrylic.