crt

128 Articles

Old TV To RGB

March 8, 2023 by 19 Comments

As CRT televisions have faded from use, it’s become important for retro gaming enthusiasts to get their hands on one for that authentic experience. Alongside that phenomenon has been a resurgence of some of the hacks we used to do to CRT TV sets back in the day, as [Adrian’s Digital Basement] shows us when he adds an RGB interface to a mid-1990s Sony Trinitron.

Those of us lucky enough to have lived in Europe at the time were used to TVs with SCART sockets by the mid-1990s so no longer needed to plumb in RGB signals, but it appears that Americans were still firmly in the composite age. The TV might have only had a composite input, but this hack depends on many the video processor chips of the era having RGB input pins. If your set has a mains-isolated power supply then these pins can be hooked up with relative ease.

In the case of this little Sony, the RGB lines were used by the integrated on-screen display. He takes us through the process of pulling out these lines and interfacing to them, and comes up with a 9-pin D connector with the same pinout as a Commodore monitor, wired to the chip through a simple RC network and a sync level divider. There’s also a switch that selects RGB or TV mode, driving the OSD blanking pin on the video processor.

We like this hack just as much as we did when we were applying it to late-80s British TV sets, and it’s a great way to make an old TV a lot more useful. You can see it in the video below the break, so get out there and find a late-model CRT TV to try it on while stocks last!

Unsurprisingly, this mod has turned up here a few times in the past.

Continue reading “Old TV To RGB” →

A CRT Audio Visualiser For When LEDs Just Won’t Do

March 4, 2023 by 17 Comments

It has been a recurring feature of consumer audio gear since the first magic eye tube blinked into life, to have some kind of visualization of the sound being played. Most recently this has meant an LED array or an OLED screen, but [Thomas] has gone one better than this with a CRT television converted to perform as a rudimentary oscilloscope.

The last generation of commonly available monochrome televisions were small 5″ CRT models made in China. They never received digital tuners, so as digital TV has become the norm they are now useless to most people. Thus they can often be found for pennies on the second-hand market.

[Thomas]’s hack involves gutting such a TV and retaining its circuitry, but disconnecting the line driver from the deflection yoke. This would normally leave a vertical line on the screen as it would then be moved only by the frame driver at 50 Hz for PAL or 60 Hz for NTSC. By connecting an audio loudspeaker amplifier to the line deflection yoke he gets that low quality oscilloscope. It would be of limited use as an instrument, but few others will have such a cool audio visualizer. He’s viewing the screen in a portrait orientation, we’d be tempted to rotate the yoke for a landscape view.

It’s worth pointing out as always that CRT TVs contain high voltages, so we’d suggest reading up on how to treat them with respect.

Continue reading “A CRT Audio Visualiser For When LEDs Just Won’t Do” →

This CRT-Style Pi Portable Gets All The Details Right

February 12, 2023 by 12 Comments

A quick glance at the “Pi Terminal” built by [Salim Benbouziyane], and you might think he pulled an old CRT monitor out of a video editing bay and gutted it. Which, of course, is the point. But what you’re actually looking at is a completely new construction, featuring a fully 3D printed enclosure, a clever PCB control panel, and some very slick internal engineering.

[Salim] started the design by recreating the principle components of the build, namely the 8 inch 4:3 IPS LCD panel and Raspberry Pi 4, digitally in CAD. This let him design the enclosure around the parts, rather than trying to cram everything in after the fact. After printing the case, which clearly took considerable inspiration from broadcast video monitors of the early 2000s, he then painstakingly post-processed the parts using tips and techniques picked up from prop builders. To really finish things off, he designed his control panel as a PCB so he could have it professionally fabricated, and used heat set inserts to hold everything tight. Continue reading “This CRT-Style Pi Portable Gets All The Details Right” →

Wii Turned Expansion Card For Broadcast Monitor

January 22, 2023 by 9 Comments

For the proper retro gaming aesthetic, plenty of gamers look to old CRT displays. Older games can look better on these displays because the original programmers took their visual characteristics into account. Finding a CRT from the 90s or early 2000s is one option, but an even better option is a broadcast video monitor (BVM) which were extremely high quality CRTs with some other features, like the ability to install a Wii straight to an expansion port on the monitor itself (Nitter).

These monitors were, as their name implies, made for broadcast TV productions. As such, they don’t have the typical video connections that might be found on a consumer unit. Instead, they used modular cards to interface with the monitor. Thanks to an open design for cards made for Sony monitors, [ShankMods] was able to make one for the Wii by “trimming” away the unnecessary parts of the console’s PCB and mapping its video and audio outputs to the slot connector.

While the Wii might not be everyone’s idea of retro, it was still a console that came out when plenty of people still had CRTs as their primary home television. It isn’t as necessary to have a CRT for a Wii as some of the older consoles, but it was very easily adaptable to this single-board design. If you don’t have a CRT and still want the CRT feel, there are ways of retrofitting a more modern display to get this effect, though.

Thanks to [Jonas] for the tip!

Fifteen Flat CRTs And A Bunch Of Magnets Make For Interactive Fun

January 6, 2023 by 46 Comments

If you were a curious child growing up when TVs were universally equipped with cathode ray tubes, chances are good that you discovered the effect a magnet can have on a beam of electrons. Watching the picture on the family TV warp and twist like a funhouse mirror was good clean fun, or at least it was right up to the point where you permanently damaged a color CRT by warping the shadow mask with a particularly powerful speaker magnet — ask us how we know.

To bring this experience to a generation who may never have seen a CRT display in their lives, [Niklas Roy] developed “Deflektron”, an interactive display for a science museum in Switzerland. The CRTs that [Niklas] chose for the exhibit were the flat-ish monochrome tubes that were used in video doorbell systems in the late 2000s, like the one [Bitluni] used for his CRT Game Boy. After locating fifteen of these things — probably the biggest hack here — they were stripped out of their cases and mounted into custom modules. The modules were then mounted into a console that looks a little like an 80s synthesizer.

In use, each monitor displays video from a camera mounted to the module. Users then get to use a selection of tethered neodymium magnets to warp and distort their faces on the screen. [Niklas] put a lot of thought into both the interactivity of the exhibit, plus the practical realities of a public installation, which will likely take quite a beating. He’s no stranger to such public displays, of course — you might remember his interactive public fountain, or this cyborg baby in a window.

Continue reading “Fifteen Flat CRTs And A Bunch Of Magnets Make For Interactive Fun” →

A tiny CRT showing an eye, inside a plexiglass enclosure

This Eye Is Watching You From Its Tiny CRT

October 9, 2022 by 25 Comments

The days of cathode ray tubes, or CRTs, are firmly behind us, and that’s generally a good thing. Display tubes were heavy, bulky and fragile, and needed complicated high-voltage electronics in order to work. But not all of them were actually large: miniature display tubes were also produced, for things like camcorder viewfinders, and [Tavis] from Sideburn Studios decided to turn one of those into a slightly creepy art project.

The heart of this build is a one-inch CRT that was salvaged from an RCA video camera. [Tavis] mounted the tiny tube inside an acrylic box on a 3D printed base. Inside that base sits a Raspberry Pi along with a high-voltage driver and a power management board. The Pi continuously plays a video that shows a human eye blinking and looking in various directions. Just an eye, floating in space, looking at the world around it.

The magic is briefly lost when the Pi starts up, because it then shows a microscopic version of the Pi’s standard bootup sequence, but once the thing is running it adds a weird vibe to a room. It actually looks like something you’d find in an avant-garde art exhibition — in the video (embedded below) it’s accompanied by eerie music that gives it an even more unsettling feel. Electronic eyes are always a bit scary, especially when they’re actually looking at you.

Continue reading “This Eye Is Watching You From Its Tiny CRT” →

A CRT Monitor From An Obsolete Logic Analyzer

October 7, 2022 by 15 Comments

The designers of older equipment that contained a CRT monitor rarely made the effort to design their own driver and deflection circuitry. Instead they were more likely to buy an off  the shelf assembly from a monitor manufacturer, and simply supply it with their video. [TomV] has an old HP 16500A logic analyzer, and in it he found a Sony monitor chassis. With a quest for a microfiche service manual and a bit of reverse engineering, he was able to hook it up to a VGA port and use it as an extension monitor for his laptop.

The monitor chassis is a Sony CHM-9001-00, which sports their 10″ Trinitron tube. These were among the very best CRT tubes of the day, making it the type of module 1990s hacker would have been very pleased to get their hands on. Here in 2022 a look at the monitor’s 40-pin connector reveals a standard RGB interface which the service manual confirms is within the voltage range to be driven from a VGA output. A Thinkpad X220 is pressed into service, with a 576 by 360 pixel at 60 Hz video mode defined, and there we have it, a modern desktop on an obsolete piece of test equipment.

The intended destination for this monitor is a small arcade cabinet, so it needed to be independent of the HP chassis. The required 120 VDC supply comes from an inverter designed for solar battery charging, which balked at the inrush current from the monitor when fed with 12 V. Increasing the supply voltage on the low voltage side solved that, leading to a very serviceable monitor. We have no use for one, but we’d be lying if we said we didn’t want one.

Perhaps you may have wondered, what made Trinitrons so good?