The CRT Edition

On TVs, technology, and robustness

Josh Reich (JR) is a med school drop out, former CEO of the online bank, Simple, and former goat and cattle farmer. He recently moved back to Australia after 17 years in America. When not spending time with his wife and two toddlers, he dabbles in electrical and mechanical engineering projects. He also wrote The Micro to Macro Edition.

Josh here. Right now on eBay you can find a used 25” Cathode Ray Tube (CRT) monitor. It’s not HD, doesn’t have digital inputs, it’s big, and it’s heavy. It’s also $2,500.

For years, if you were looking to buy a CRT monitor or TV, you could find them for essentially $0 at thrift stores or on the side of the road. But those days have gone. And clearly the supply of new CRTs has diminished to zero. But the price wouldn’t be this high unless there was demand.

Why is this interesting?

The demand for CRTs doesn’t come from their superior contrast—you can get that from modern OLEDs and event LCDs\. Rather, it comes from the fact that they’re cool.

If you look at eBay, you’ll see that CRTs are being marketed to retro-computing gamers. Old games are low resolution affairs, so the pixelated graphics play well with the distinct phosphors behind the glass of a CRT. Today, with Retina™ phone displays and 8K TV’s, we’re forgetting what pixels look like. On a CRT, they’re hard to miss.

There’s an authenticity that comes from using a real CRT. If you’ve gone to the trouble of saving a classic 80’s arcade game from a dumpster—replacing all the leaky capacitors on the logic boards and touching up the graphics on the cabinet—it would be a shame to replace the broken display with an LCD panel. It would be like sticking a Prius engine in your fully restored ‘68 Camaro.

The other reason that CRT’s are cool is because they’re analog devices. CRTs come from an era before integrated circuits. They are the last actively used vestiges of the era of vacuum tube electronics. The circuit that decodes a TV signal and converts it into the movement of an electron beam to generate an image is pretty straightforward. 

This is pretty important for retro computing in general. Before the capabilities unlocked by digital processing, a variety of hacks were used to push the limits of the technology of the time. To start with, TV and some computer graphics modes would split each frame into two fields, one half containing the odd lines, followed by even lines from the image. 

There’s no easy way to display interlaced footage on a modern progressive mode screen. Naively adding the two fields together into a single frame results in jarring motion blur that appears as every second line being offset. It gets even worse with the wide range of frame rates and scan rates exploited by game designers to make the most of technology of the time. Many of those games won’t even display on an LCD due to their use of technically unsupported graphics modes. 

Jon Postel, one of the key architects of the internet, had a principle for the design of distributed systems: “Be conservative in what you do, be liberal in what you accept from others.” Analog electronics frequently obey Postel’s law, either by design, or because they’re too dumb to know better. If you’re of a certain age, you’ve had the experience of a well loved audio tape still playing with all of its warps and warbles from the tape being stretched. Analog devices frequently have elegant failure modes—unlike the jarring skips on scratched CDs.

You can take the RCA audio cable coming out of your stereo and stick it into the composite video input of an old CRT TV—and you’ll see stuff. Stuff that’s in sync with the music. The designers of the analog video standard never expected you to do that, but it works because of how basic the circuitry is that interprets what it should expect. Audio signals look nothing like a video signal, but the circuitry chugs along and does its best. 

If your modern LCD TV even has an analog video input, it will just show a blank screen if you put a non-compliant signal into it. That’s boring.

There’s an entire world of folks—modern-day descendants of Nam June Paik—who abuse analog video signals for creative purposes. There’s video artists, VJs, and folks just tripping out to the weird stuff that happens. That kind of creativity only works on CRTs. (JR)

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Thanks for reading,

Noah (NRB) & Colin (CJN) & Josh (JR)

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