You can run XABACUS via FREEWARE_DEMO.COM procedure ANYTHING SPECIAL IN USING? Click on the left mouse button on a bead you want to move. Click on the right mouse button or press 'C' or 'c' if you want to clear the abacus. 'Q', 'q', Control-C to kill program. There are books on how to use an abacus, but basically all it does is add and subtract, the rest you have to do in you head. Essentially, this is a proof by induction that a computer is more powerful than an abacus, since a computer program can contain an abacus. (But then again, you can simulate a computer within a computer, so what does that show). Actually, with a real abacus, one can move more than one row at a time with 10 fingers. But on the other hand, a real abacus does not have the current sum displayed as an integer. Sources are available under [.SRC] directory in XABACUS.ZIP file Patrick Moreau pmoreau@cena.dgac.fr moreau_P@decus.decus.fr