What did "computer geek" type people do before computers were invented?

On a side note, we literally had train autism before trains were invented: https://www.ancientmedicine.org/home/2018/4/6/heraclides-of-...

I guess they had a lot of time to study and tinker

I think my great-grandfather fits the type. He was an X-ray technician, starting in the 19-teens - learned the trade, in fact, from a man who'd studied with Roentgen. This is in the age when one had to make one's own vacuum tubes, and get really deeply into electronic theory and practice to make it work, and every setup was, to some extent, bespoke.

X-ray led him into amateur photography - he'd take off-cuts from the large-format films home and wind his own cartridges in the darkroom he built in his basement. My dad inherited his pre-war Leica camera, and I have a few of his (very good) prints on my walls.

The electronics led him into amateur radio. In the 1920s the airwaves were so clear that with a 1w set he was able, from San Francisco, to contact fellow hams in Germany and New Zealand; my grandfather rembered several of them coming to visit.

He was, I suspect, from stories about his extreme social awkwardness, somewhere on the spectrum. Definitely a geek.

Electronics and ham radio hobbyists were the equivalent of computer geeks. In fact, the first home computers were electronic kits that needed to be assembled before they could be used.

Hacking the phone system to make long-distance calls was a thing too.

I'm sure there have always been people who hyper-focused on something. In the 1800s it was probably scientific experiments.

In the 20th century, trainspotters, radio hams, people who built toy model railways or had toy soldiers, science fiction fans, chess players come to mind. See also https://en.wikipedia.org/wiki/Anorak_(slang)

Ca. 1200, hydraulics: https://news.ycombinator.com/item?id=42482805

To be clear: "Before computers were invented" goes a long way back, arguably before about 1940 but some could bring up Charles Babbage, for whose unrealized mechanical computer an actual program was famously written by one Ada Lovelace.

So let's say "before computers were available to ordinary folks".

Speaking for myself (as a kid)... Consumer electronics back then were much more recyclable than now. Almost every component out of, say, a dead TV could be snipped or unsoldered to use in new projects.

If the recycled parts were loudspeakers, especially in matched pairs - try to make stereo speakers that sound good. Build crystal radio sets. Try to understand the mysterious new art of digital logic, though necessarily at the dozens-of-gates level. The analog world was fascinating, there were so many things you might some day understand/play with, such as ham radio or the phone network, which back then was about the most complex thing anyone interacted with. In fact, a lingering fascination with the phone network drove me (decades ago) into my employment in telecommunications.

Very interesting question. I can only look at the local history of the place I grew up in, but in our case the accessibility of computers post '95 created the computer geek to a large extent. People wouldn't have locked themselves up in their bedrooms for their whole teenage years otherwise. Although there were many geeky/nerdy alternative hobbies, consider that as an alternative we might have just got out of the bedroom and spent more time socializing and doing other more normal and less geeky hobbies.

But to answer you question: if I didn't have internet, specifically, I'd be spending more time at the local library. Besides that, electronics, cars/motorcycles/engines, carpentry, model aircraft, gardening and animal husbandry are things I could see myself dabbling in but probably not with the same intensity and single focus so not directly comparably to the time I spend tapping on a keyboard.

Ham radio, Hi-fi (often home-built stereo equipment), model trains.

Radios and such before computers.

Telegraphs and motors before that.

Machine shop stuff before that.

Blacksmithing before that

Agriculture before that, along with astronomy.

They built radios.

In high school many of us were deep into math.

I suppose they did the same sorts of things pianists did before pianos.

Edit: and built radios.

Well, hackers made furniture with hatchets apparently.

We had RadioShack! We built our own electronics.

Radio, audio / hifi, electronics, engines, cars, trains, aircraft, etc...

For me, the more mysterious question is, what is the next thing to geek out on now that "computers" has turned into surveillance capitalism and advertising?

They had mental problems, i suppose.

Crossword puzzles.