FALKEN SCAHCH - DAS KOMPLETTE SCHACHPROGRAMM published in 1989 is written in German and was never sold in other languages. The program tries to teach chess as well as provide an adequate chess program to play and improve against. It also allows you to program your favorite chess openings, which was a first at the time.
The different GAME OPTIONS are difficult to find. You have to experiment holding the TAB, SHIFT and CTRL keys while pressing different keys on your keyboard in order to find all the different options available. A few useful OPTIONS are shown in the pictures below.
You can read about the original FALKEN SCHACH here:
The approximate rating for FALKEN SCHACH is 1400-1500 Elo (1600 - 1700 USCF).