I just watched some of TV interviews with the family and saw the rest of his work, and it's pretty amazing. Check out Invaders in 512 bytes [1][2], or Aardvark game for the Atari 2600 ([3]).
Also seems he has just self-published a book (as of July 27):
Do you would like more details on the inner workings? This program is fully commented in my new book Programming Boot Sector Games and you'll also find a 8086/8088 crash course! Now available from Lulu [4]
[1] https://github.com/nanochess/Invaders
[2] https://www.youtube.com/watch?v=pC976eejfms
[3] https://www.youtube.com/watch?v=HNZfw6jShng
[4] http://www.lulu.com/shop/oscar-toledo-gutierrez/programming-...