Bringing An ADM-3A Back To Life

[David] at Usagi Electric ended up with an old Lear Siegler ADM-3A terminal in a trade a couple of years ago. But the CRT face was plagued with so-called cataracts, and the condition of the insides was unknown. The video ( below the break ) shows the restoration process, which went quite smoothly. [David] was relieved that the CRT repair in particular was easy, a fact he attributes to the Texas weather —

ADM-3A Under the Hood

The temperature was 110 F / 43 C when he set the CRT outside to bake in the sun for a few hours. Afterwards, removing the “integral implosion protection” plastic screen went better than expected. Everything cleaned up nicely and the screen reinstalled. Introduced in 1976, the main electronics board is chock full of TTL chips with nary a microprocessor in sight. Fortunately the board was substantially intact, and a single missing chip was found hidden underneath the board. [David] gets the terminal up and running in short order, and is confronted with an annoyance familiar to gray-haired programmers who grew up in this era. Most terminals had different sets of commands to control features such as cursor control and clearing parts or all of the screen. Programs often assumed a certain type of terminal. Some terminals could be configured to behave in different ways, and some programs offered the user a choice of terminals. Today your terminal emulator probably still has a few choices of which kind of terminal to emulate, VT-100 being the most common. And eventually some operating systems provided a terminal abstraction, like Unix’s termcap for example.

If you were around in the era where terminals like the ADM-3A were scattered everywhere, what was your favorite terminal and/or terminal feature? And today, do you have any favorite terminal emulator to recommend? Let us know in the comments below.

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New Motherboard Improves Old CRT Television

While browsing AliExpress from his digital basement, [Adrian Black] stumbled upon what seemed like a brand-new mainboard for a CRT television set. He decided to take a gamble and ordered one. It finally arrived, and was indeed a brand new product from 2023.

DIGITAL MAIN BOARD OF TV, Work ath [sic] HONGXUN products with the care and precision of a sculptor in each step, wonderful have no limits

CRT Mainboard Transplant in Progress

Dubious marketing descriptions like “High Definition Digital Color TV Driver Board” aside, this turned out to be a fairly well-designed analog TV board. [Adrian] pulls a 20-year-old Magnavox ( Philips ) color television set from storage and begins the transplant operation. One interesting observation is the Magnavox board has almost the same layout as the new board, except for the orientation of the sections. The new CRT neck board had a different connector than the Magnavox set, but was designed to accept multiple sized sockets. [Adrian] just removed the new socket and replaced it with one from the old set. The mechanical issues were a bit more complicated, but nothing that a Dremel tool and a bit of hot glue can’t fix. The 220 VAC power supply was eventually modified to accept 110 VAC, which also enabled him to reconnect the degaussing coil.

[Adrian] has collected some relevant documentation in this GitHub repository, including schematics. Why bother with this at all? Well, until now, he didn’t have any way to test / view PAL RF signals in his lab. He was gambling on the new mainboard having a PAL tuner. It does, but as an unadvertised bonus, it supports NTSC and SECAM as well — but still not “HD digital color TV”, as far as we know. If you want a multi-standard TV in your lab, this solution may be worth considering. It appears there is still a market somewhere for new CRT televisions. If you have any background on this, please let us know down below in the comments.

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A man next to a robot with animatronic eyes and a CRT display showing an audio waveform

Animatronic Alexa Gives Amazon’s Echo A Face

Today, we’re surrounded by talking computers and clever AI systems that a few decades ago only existed in science fiction. But they definitely looked different back then: instead of a disembodied voice like ChatGPT, classic sci-fi movies typically featured robots that had something resembling a human body, with an actual face you could talk to. [Thomas] over at Workshop Nation thought this human touch was missing from his Amazon Echo, and therefore set out to give Alexa a face in a project he christened Alexatron.

The basic idea was to design a device that would somehow make the Echo’s voice visible and, at the same time, provide a pair of eyes that move in a lifelike manner. For the voice, [Thomas] decided to use the CRT from a small black-and-white TV. By hooking up the Echo’s audio signal to the TV’s vertical deflection circuitry, he turned it into a rudimentary oscilloscope that shows Alexa’s waveform in real time. An acrylic enclosure shields the CRT’s high voltage while keeping everything inside clearly visible.

To complete the face, [Thomas] made a pair of animatronic eyes according to a design by [Will Cogley]. Consisting of just a handful of 3D-printed parts and six servos, it forms a pair of eyes that can move in all directions and blink just like a real person. Thanks to a “person sensor,” which is basically a smart camera that detects faces, the eyes will automatically follow anyone standing in front of the system. The eyes are closed when the system is dormant, but they will open and start looking for faces nearby when the Echo hears its wake word, just like a human or animal responds to its name.

The end result absolutely looks the part: we especially like the eye tracking feature, which gives it that human-like appearance that [Thomas] was aiming for. He isn’t the first person trying to give Alexa a face, though: there are already cute Furbys and creepy bunnies powered by Amazon’s AI, and we’ve even seen Alexa hooked up to an animatronic fish.

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Old TV To RGB

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.

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

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.

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This CRT-Style Pi Portable Gets All The Details Right

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

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!