https://www.youtube.com/watch?v=TD6lcIIOeic
https://www.youtube.com/watch?v=LpuPe81bc2w

hex conversion:
https://www.youtube.com/watch?v=6plMoviKDs0&index=5&list=PLhCl0ln3o55z3HXfnOvtqEQSw0f1qgAzQ

tom Lehrer:


https://www.youtube.com/watch?v=UIKGV2cTgqA&feature=iv&src_vid=6plMoviKDs0&annotation_id=annotation_2856543293

binary, from 6:36 to 12:10:
https://www.youtube.com/watch?v=vT9p2QnIycI&index=4&list=PLhCl0ln3o55z3HXfnOvtqEQSw0f1qgAzQ