One friend sold TRS-80's when he managed a Radio Shack store. Another friend got his start building a Heathkit 8088 computer- he's worked with airline reservations systems (with their unique operating system) for 35 years.

Portland's Powell's Books has a collection of antediluvian computers. I hope the collection survives the economic challenges of the pandemic: https://www.flickr.com/photos/jefurii/2150123039