Sharpest Color CRT Display is Monochrome Plus a Trick

I recently came across the most peculiar way to make a color CRT monitor. More than a few oscilloscopes have found their way on to my bench over the years, but I was particularly struck with a find from eBay. A quick look at the display reveals something a little alien. The sharpness is fantastic: each pixel is a perfect, uniform-colored little dot, a feat unequaled even by today’s best LCDs. The designers seem to have chosen a somewhat odd set of pastels for the UI though, and if you move your head just right, you can catch flashes of pure red, green, and blue. It turns out, this Tektronix TDS-754D sports a very peculiar display technology called NuColor — an evolutionary dead-end that was once touted as a superior alternative to traditional color CRTs.

Join me for a look inside to figure out what’s different from those old, heavy TVs that have gone the way of the dodo.

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Freeforming the Atari Punk Console

This stunning piece of art is [Emily Velasco’s] take on the Atari Punk Console. It’s a freeform circuit that synthesizes sound using 555 timers. The circuit has been around for a long time, but her fabrication is completely new and simply incredible!

This isn’t [Emily’s] first rodeo. She previously built the mini CRT sculpture project seen to the left in the image above. Its centerpiece is a tiny CRT from an old video camera viewfinder, and it is fairly common for the driver circuit to understand composite video. And unlike CRTs, small video cameras with composite video output are easily available today for not much money. Together they bring a piece of 1980s-era video equipment into the modern selfie age. The cubic frame holding everything together is also the ground plane, but its main purpose is to give us an unimpeded view. We can admire the detail on this CRT and its accompanying circuitry representing 1982 state of the art in miniaturized consumer electronics. (And yes, high voltage components are safely insulated. Just don’t poke your finger under anything.)

With the experience gained from building that electrically simple brass frame, [Emily] then stepped up the difficulty for her follow-up project. It started with a sound synthesizer circuit built around a pair of 555 timers, popularized in the 1980s and nicknamed the Atari Punk Console. Since APC is a popular circuit found in several other Hackaday-featured projects, [Emily] decided she needed to add something else to stand out. Thus in addition to building her circuit in three-dimensional brass, two photocells were incorporated to give it rudimentary vision into its environment. Stimulus for this now light-sensitive APC were provided in the form of a RGB LED. One with a self-contained circuit to cycle through various colors and blinking patterns.

These two projects neatly bookend the range of roles brass rods can take in your own creations. From a simple frame that stays out of the way to being the central nervous system. While our Circuit Sculpture Contest judges may put emphasis the latter, both are equally valid ways to present something that is aesthetic in addition to being functional. Brass, copper, and wood are a refreshing change of pace from our standard materials of 3D-printed plastic and FR4 PCB. Go forth and explore what you can do!

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Daphne Oram and the Birth of Electronic Music

For most of human history, musical instruments were strictly mechanical devices. The musician either plucked something, blew into or across something, or banged on something to produce the sounds the occasion called for. All musical instruments, the human voice included, worked by vibrating air more or less directly as a result of these mechanical manipulations.

But if one thing can be said of musicians at any point in history, it’s that they’ll use anything and everything to create just the right sound. The dawn of the electronic age presented opportunities galore for musicians by giving them new tools to create sounds that nobody had ever dreamed of before. No longer would musicians be constrained by the limitations of traditional instruments; sounds could now be synthesized, recorded, modified, filtered, and amplified to create something completely new.

Few composers took to the new opportunities offered by electronics like Daphne Oram. From earliest days, Daphne lived at the intersection of music and electronics, and her passion for pursuing “the sound” lead to one of the earliest and hackiest synthesizers, and a totally unique way of making music.

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Retrotechtacular: Some Of The Last CRTs From The Factory Floor

It seems crazy having to explain what a piece of technology was like to someone who is barely fifteen years your junior, but yet we have reached that point when it comes to CRTs. There may still be remnants of CRT televisions and monitors left out in the wild, however, the chances that a kid preparing to enter high school has encountered one is slim. While there may be no substitute for the real thing, there is this raw video from [Glenn] who shared his tour of the Sony Trinitron assembly line in the early 2000s. Sony Trinitron Television

Sony Electronics’ cathode ray tube manufacturing facility was located alongside headquarters in Rancho Bernado, CA. The facility was shuttered in 2006 when Sony transitioned wholly onto digital displays like the flat-panel LCD line of Bravia televisions. [Glenn]’s video shows that the manufacturing process was almost entirely automated from end to end. A point that was made even more clear with the distinct lack of human beings in the video.

The Trinitron line of televisions first appeared in 1968. At a time where most manufacturer’s were offering black and white picture tubes, Sony’s Trinitron line was in color. That name carried through until the end when it was retired alongside tube televisions themselves. Sony’s focus on technological innovation (and proprietary media formats) made them a giant in the world of consumer electronics for over forty years in the United States, but in the transition to a digital world saw them seeding market share to their competitors.

A quick word of warning as the video below was shot directly on Sony’s factory floor so the machinery is quite loud. Viewers may want to reduce the volume prior to pressing play.

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Unique Flat-Screen Display Put to Use in CRT Game Boy

The cathode-ray tube ruled the display world from the earliest days of TV until only comparatively recently, when flat-screen technology began to take over. CRTs just kept getting bigger over that time until they reached a limit beyond which the tubes got just too bulky to be practical.

But there was action at the low end of the CRT market, too. Tiny CRTs popped up in all sorts of products, from camcorders to the famous Sony Watchman. One nifty CRT from this group, a flat(tish) tube from a video intercom system, ended up in [bitluni]’s lab, where he’s in the process of turning it into a retro Game Boy clone with a CRT display. The display, which once showed the video from a door-mounted camera, was a gift from a viewer. Date codes on the display show it’s a surprisingly recent device; were monochrome TFT displays that hard to come by in 2007? Regardless, it’s a neat design, with the electron gun shooting upward toward a curved phosphor screen. With a little Google-assisted reverse engineering, [Bitluni] was able to track done the video connections needed to use his retro game console, which uses an ESP32 that outputs composite video. He harvested the intercom speaker for game audio, added a temporary Nintendo gamepad, and soon he was playing Tetris in glorious monochrome on the flat screen.

The video below is only the first in a series where the prototype will be stuffed into one nice tidy package. It certainly still needs some tweaking, but it’s off to a great start. We can’t wait to see the finished product.

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Circuit Bending A TV For Better Input

If you haven’t noticed, CRTs are getting hard to find. You can’t get them in Goodwill, because thrift stores don’t take giant tube TVs anymore. You can’t find them on the curb set out for the trash man, because they won’t pick them up. It’s hard to find them on eBay, because no one wants to ship them. That’s a shame, because the best way to enjoy old retrocomputers and game systems is with a CRT with RGB input. If you don’t already have one, the best you can hope for is an old CRT with a composite input.

But there’s a way. [The 8-Bit Guy] just opened up late 90s CRT TV and modded it to accept RGB input. That’s a monitor for your Apple, your Commodore, and a much better display for your Sega Genesis.

There are a few things to know before cracking open an old CRT and messing with the circuits. Every (color) CRT has three electron guns, one each for red, green, and blue. These require high voltage, and in CRTs with RGB inputs you’re looking at a circuit path that takes those inputs, amplifies them, and sends them to the gun. If the TV only has a composite input, there’s a bit of circuitry that takes that composite signal apart and sends it to the guns. In [8-bit guy]’s TV — and just about every CRT TV you would find from the mid to late 90s — there’s a ‘Jungle IC’ that handles this conversion, and most of the time there’s RGB inputs meant for the on-screen display. By simply tapping into those inputs, you can add RGB inputs with fancy-schmancy RCA jacks on the back.

While the actual process of adding RGB inputs to a late 90’s CRT will be slightly different for each individual make and model, the process is pretty much the same. It’s really just a little bit of soldering and then sitting back and playing with old computers that are finally displaying the right colors on a proper screen.

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This Nearly NIMO Clock Fakes it and Makes It

Pity the aficionado of rare vintage displays. While Nixies and VFD tubes get all the attention and benefit from a thriving market to satisfy demand, the rarer displays from the mid-20th century period are getting harder and harder to find. One copy of an especially rare display is hard enough to find. Six copies for a clock? That’s a tall order.

That doesn’t mean you can’t fudge it, though, which is how this faux-NIMO clock came to be. [Paul Bricmont] was inspired by [Fran Blanche]’s NIMO tube primer, wherein the rare, single-digit CRT display was put through its paces. We’ve got to admit, it’s an easy display to fall in love with, thanks to its eerie blue phosphor glow, high voltage supply, and general quirkiness. [Paul] was unable to lay hands on a single tube, though, so he faked it with six tiny TFT displays and some plastic lenses. The lenses mimic the curved front glass of the original NIMO, while the TFT displays provide the stencil-style images of each numeral. The phosphor glow comes from replacing the stock white TFT backlight with a Neopixel array that can produce just the right shade of blue-green. 3D-printed modules hold two digits each, and the usual Arduino components run the show. The effect is quite convincing, although we bet some software tweaks could add things like faux burn-in and perhaps soften the edges of the digits to really sell it.

What other rare displays could be replicated this way? Given the variety of displays that were tried in the pre-LED era, it may be a rich vein to mine.