A strange little side quest
Put Tägliches Kreuzwort Rätsel next to the history of puzzles and a few unexpected connections appear. The name Tetris combines a reference to four-square pieces with Pajitnov's interest in tennis. That old idea kept changing rather than disappearing. Spacewar! appeared on MIT's PDP-1 in 1962 and became one of the earliest influential computer games shared among programmers. That history is one reason familiar mechanics can still feel new when they are recombined well.
