alt Hacker NewsI got a handheld emulator console as a Christmas gift. Configuring shaders that emulate crt TVs, I realized I had no mental model of how those TVs worked at all.
I’m used to “pixels are three little lights combining rgb colors”, which doesn’t work here, so I went on a rabbit hole and let me tell you, analog TVs are extremely impressive tech.
Getting an electron beam to hit a glass, making the chemicals on it spark, covering it in a “reading motion” for hundreds of lines, and doing that 60 times a second! And the beam is oriented by just careful usage of magnets. It sounds super sci-fi for an already dead, 130 years old technology.
I also learned that my childhood was a lie. Turns out that the logic in consoles of the time was tied to the speed of the beam, which in turn used alternating current’s frequency as a clock. This means that since European current changes 50 times per second rather than 60, our games played in slowmo (about 0.8x). American sonic was so much faster! And the music was so much more upbeat!
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> Turns out that the logic in consoles of the time was tied to the speed of the beam, which in turn used alternating current’s frequency as a clock. This means that since European current changes 50 times per second rather than 60, our games played in slowmo (about 0.8x). American sonic was so much faster! And the music was so much more upbeat!
Wasn't this the reason behind different versions of the game for PAL and NTSC etc.? So I imagine the games would play quite similarly, just with a lower refresh rate in Europe?
What other sci fi technology is being lost on us now? I always that the complexity of the local-battery-powered copper-cable telephone exchange system was bonkers. It was the backbone for all our landline calls.
well, not quite with the 50hz thing. They slowed them down to run at 50hz, but they could've rewritten them to work at full speed by dropping frames
Don't forget how they found a way to squish closed caption information into analog broadcast. The electron beam traces a path on the CRT display by drawing the odd lines from top to bottom (which draws half the image) and then the even lines (the rest of the owl) from top to bottom. While the electron beam is repositioning itself from the bottom of the screen to the top of the screen, there is a brief period of time where other data can be transmitted. That's where closed caption data was shoehorned in.