A differential analyzer is a mechanical, analog computer that can solve differential equations. Differential analyzers aren’t used anymore because even a cheap laptop can solve the same equations much faster—and can do it in the background while you stream the new season of Westworld on HBO. Before the invention of digital computers though, differential analyzers allowed mathematicians to make calculations that would not have been practical otherwise.

In the late 1970s, the computer, which for decades had been a mysterious, hulking machine that only did the bidding of corporate overlords, suddenly became something the average person could buy and take home. An enthusiastic minority saw how great this was and rushed to get a computer of their own. For many more people, the arrival of the microcomputer triggered helpless anxiety about the future. An ad from a magazine at the time promised that a home computer would “give your child an unfair advantage in school.” It showed a boy in a smart blazer and tie eagerly raising his hand to answer a question, while behind him his dim-witted classmates look on sullenly. The ad and others like it implied that the world was changing quickly and, if you did not immediately learn how to use one of these intimidating new devices, you and your family would be left behind.

I was not yet alive in 1983. This is something that I occasionally regret. I am especially sorry that I did not experience the 8-bit computer era as it was happening, because I think the people that first encountered computers when they were relatively simple and constrained have a huge advantage over the rest of us.

Today, (almost) everyone knows how to use a computer, but very few people, even in the computing industry, grasp all of what is going on inside of any single machine. There are now so many layers of software doing so many different things that one struggles to identify the parts that are essential. In 1983, though, home computers were unsophisticated enough that a diligent person could learn how a particular computer worked through and through. That person is today probably less mystified than I am by all the abstractions that modern operating systems pile on top of the hardware. I expect that these layers of abstractions were easy to understand one by one as they were introduced; today, new programmers have to try to understand them all by working top to bottom and backward in time.

Subscribers to Popular Electronics were a sophisticated group. The magazine’s editor, Arthur Salsberg, felt compelled to point out as much in the editorial section of the December 1974 issue. The magazine had received letters complaining that a recent article, titled “How to Set Up a Home TV Service Shop,” would inspire a horde of amateur TV technicians to go out and undercut professional repairmen, doing great damage to everyone’s TVs in the process. Salsberg thought this concern was based on a misunderstanding about who read Popular Electronics. He explained that, according to the magazine’s own surveys, 52% of Popular Electronics subscribers were electronics professionals of some kind and 150,000 of them had repaired a TV in the last 60 days. Moreover, the average Popular Electronics subscriber had spent $470 on electronics equipment ($3578 in 2018) and possessed such necessities as VOMs, VTVMs, tube testers, transistor testers, r-f signal generators, and scopes. “Popular Electronics readers are not largely neophytes,” Salsberg concluded.

The Altair 8800 was a build-it-yourself home computer kit released in 1975. The Altair was basically the first personal computer, though it predated the advent of that term by several years. It is Adam (or Eve) to every Dell, HP, or Macbook out there.