I did a little bit. Mostly, I would tinker with other people's code, especially the "demo's" you'd that run before 'ambiguously' licensed games.
I'd like to take them apart and get a particular feature working, say the theme from Mission: Impossible or a key click sound and incorporate them into my programs. Usually, I'd load them and call them from my basic program. I guess it was a pre-cursor to using DLL's.
You know, looking back, I think I should have been more brave about hardwiring a reset switch, but at the time, my folks' would not have sprung for a another computer.
Also, I think I would have gone further into assembly language if I could have found the resources, like books or other people. Most of the kids in my neighborhood weren't into computer programming, let alone programming them in assembly. I wrote a game called 2010, based on the movie, and that pretty much blew my friends away. Not to sound too arrogant, but I pretty much rose to the top of my peer group. I found that I wanted to know more, but was limited by who I knew.
That's what is so great about the internet, usenet, sites like MSDN and Channel 9. You can tap the collective knowledge of practically everybody.
Another funny story from the era, there was a reclusive hacker type who was known to hand out pirated video game disks to all the kids in the neighborhood. His landlord freaked out because he thought the guy was dealing drugs. The police even came to investigate and saw that "he was only giving out computer disks." This was the early 1980s, long before the word software was in people's vocabulary.
He eventually ended up setting up a bbs and my friend who had the 1200 baud modem spent hours upon hours downloading games he would never play. My parents would never let me have a modem. They were expensive and they had just seen the Wargames movie, which filled their hearts with fear or would that be ph34r?