Authors:

This is a family production by Harald Bartel (AI, main code),
Ulf Bartel (C conversion) and Karl Bartel (graphics). Once 
tested by Holger Bartel (who lost).

  e-mail:
    Harald Bartel <harald.bartel@prozentor.de>
    Karl Bartel <karlb@gmx.net>
    Ulf Bartel <ulfi@cs.tu-berlin.de>