Any idea why some textbooks especially those used in universities make some of their content available through the web, not included in the book? What's the point? I cannot see adding extra less than 100 pages an issue.
I've got a copy of Modern Physics by Serway, Moses, and Moyer. It comes with a 3.5" floppy with some software on it. You can't follow some of the examples without the software and you can't do some of the problems. I don't have a floppy reader on my computer so I can't use it. I wish the material on that disk were available online.