One difference I recall is you had to read manuals first. Now, you just code, and when you get stuck: google or stack overflow. But with no good search engines, you couldn't search books like that, so your chance of finding an answer by searching was poor. You wanted to have read the book first, so it was in your head.

Also: way fewer libraries. You might write ALL of an application. You might call the OS to just to read/write files. Today is much more gluing together libraries, which is nowhere near as much fun.