Most trade magazines of that era were pretty similar in size and number of ads , eg. PC Magazine. Pre-Internet they were one of the only ways to keep up with industry news, topics and products.
There were, and still are, a number of magazines in the electronics industry, EDN, for example, that were available for free to engineers that were 75% ads with a few articles. The publishers and advertisers expected the articles to draw the engineers who would be the ones to spec components for their current designs.
EDN - Voice of the Engineer
https://www.edn.com
Electronic Design News (EDN) is an electronics community for engineers, by engineers.
Find the latest articles, magazines, tools, and blogs in the industry.