Up until the late 1970s consumer electronic component manufacturers rushed data
and applications for all new products into the channels used by end-product
manufacturers. This included all tubes, transistors (with some house-marked
exceptions), and SSI (small-scale integrated circuits). The first integrated
circuit I'm aware of getting into consumer electronics without
generally-available documentation was ~1979. (I think it was an Atari video
processor.)

Most tube and semiconductor foundries promotion targeted college engineering and
hobby circles. Engineers used the components they'd become familiar with during
low-pressure experience. Managers faced deadlines and were happy enough to have
engineers use circuits and software developed in school or at home. The hobby
magazines published hardware hacks. Some found their way into products. Even
after the first propitiatory consumer ICs, the tendency to use the
well-documented, multi-foundry, multi-sourced applications products continued
into the 1990s.

The equivalent today would be selecting one of the better documented WiFi chip
sets and publishing projects using it with the Arduino, BASIC Stamp, PIC, and
extra tricks when using it with laptop and desktop machines.

Publications similar to those of 40 years ago still exist.

http://www.circellar.com/

http://www.elektor-usa.com/

http://makezine.com/

http://www.nutsvolts.com/

Or any widely-read technical communication.