!!!Atari Educational System - programming cassette streams
Thom from AtariAge did discover how the cassettes for the Atari and Dorsett Educational System can be programmed. In the near future he will publish a book on that. Until that time, please take a look here:
[EduEncode|http://atariage.com/forums/topic/238262-eduencode-a-library-for-encoding-atari-educational-system-tapes/]