X-BASED ABACUS
============== Abacus X widget, V4.3
One of the motivations of this abacus program is simplicity. This
was originally a demonstration that I could write a window program.
Use "mouse-left" to move beads. Note you can move them faster
by holding down the button and sweeping across beads. Use
"mouse-right", "C",or "c" to clear. "Q",
"q", or "CTRL-C" keys kill program.