I actually wondered about this on Twitter recently[1]. Do you remember caring about/recognizing the aesthetics of some of these ads at the time, or is that more of a modern perspective?
Aside from the aesthetics, the content of the ads was different than today. There was lots of advertising aimed directly at hobbyists. Today, you mostly have to go to specific niche places like tindie.com to find something similar. Or basically, a significant portion of the market was people with engineering skills.