This is very cool! To run this on a modern Linux, install Ghostscript and run it like this:

    gs -dNOSAFER tetris.ps

In another terminal in the same working directory, run the command it gives in the source file:

    stty raw -echo; cat >> t.txt

Keep the second terminal focused for your keyboard inputs. I don't know if there's an elegant way to quit, but I just close the Ghostscript window and kill the second terminal.