• Daedskin@lemm.ee
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    9 months ago

    I’m sure there were other consoles that did it, but the one I remember is the NES; it had a physical switch on it for channel 3 or 4, and you had to have your TV tuned to the respective channel to get the game to show up. As to why that was necessary on a technical level, I’m not sure. But it was a thing you had to do.

    • mokus@lemmy.blahaj.zone
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      9 months ago

      It’s because the console was encoding the video in the same NTSC format that tv stations transmitted over the airwaves at the time, and the little adapter box it came with would connect between the tv and the antenna and the console, and merge the console’s signal with the antenna’s signal, so the TV would detect it as if the antenna had picked it up.

      It had a channel selector to let you pick which of two frequencies to center the console’s signal at, in case one or the other was in use by a real tv station. Where I and apparently the previous poster lived, “channel 3” was unused but “channel 4” had a tv station so only channel 3 worked for video games

      • mokus@lemmy.blahaj.zone
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        9 months ago

        At a specifically technical level, that adapter box contained a RF oscillator and a “frequency mixer” - the mixer likely being made of a transistor or 2 being switched on and off by the RF oscillator at a very high speed, with the effect of frequency-shifting the signal from the console. It’s similar to the way a camera’s shutter speed shifts the frequency of things like car wheels, helicopter blades, old tv’s and some LED dimmers to make the frequencies of those things visible to the human eye. Radio systems are almost all built on that concept.

        it’s possible that channel 4 just plain didn’t work very well in that design but in my area I’m pretty sure it was just interference. I remember that channel 4 looked empty at first glance but if you sat and watched the snow, it would occasionally pick up some very faint stuff - there was likely enough RF signal there to interfere but not enough for the TV to consistently lock on.

    • Betch@lemmy.world
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      9 months ago

      It’s because it used radio frequency. Yes through a cable. The cable was basically just an antenna. The RF box in the back of your console or whatever would send the RF signal at a specific frequency, usually channel 3 but some had switches that you could change to channel 2 or 4.

      It’s basically like tuning in to a radio station.