Turning A Tiny CRT Into A Monitor

TV

[GK] picked up a few tiny 2″ CRTs a while back and for the longest time they’ve been sitting in a box somewhere in the lab. The itch to build something with these old tubes has finally been scratched, with a beautiful circuit with Manhattan style construction.

[GK] has a bit of a fetish for old oscilloscopes, and since he’s using an old ‘scope tube, the design was rather simple for him; there aren’t any schematics here, just what he could put together off the top of his head.

Still, some of [GK]‘s earlier projects helped him along the way in turning this CRT into a monitor. The high voltage came from a variable output PSU he had originally designed for photomultiplier tubes. Since this is a monochrome display, the chrominance was discarded with an old Sony Y/C module found in a part drawer.

It’s a great piece of work that, in the words of someone we highly respect is, “worth more than a gazillion lame Hackaday posts where someone connected an Arduino to something, or left a breadboard in a supposedly “finished” project.” Love ya, [Mike].

 

We Salute the Television Tube Flag

tvflag

From [Gijs] comes Beeldbuis Vlag Tijsdlijn, or television tube flag (Translated). We’re not up on our Dutch, but it appears that [Gijs] and friends have created a television tube which waves much like a flag in response to airflow from a fan.  The effect is pretty darn amazing, and that’s putting it mildly. To create this hack, [Gijs] built a modified Wobbulator. The Wobbulator is an early video synthesizer which used added steering coils to modify the operation of a standard TV tube. When excited, the coils would deflect the tube’s electron beam, causing some rather trippy images to appear on-screen. (Yes, here at Hackaday “trippy” is a scientific term).

[Gijs] wanted his screen to be “waved” by a fan, just like a flag would wave. To do this he used an anemometer made of ping-pong ball halves. The anemometer spins up a DC motor from a CD-ROM drive. In this application, the motor acts as a generator, creating a DC voltage. An ATmega328 running the Arduino code reads the voltage from the motor. If the anemometer is spinning, the Arduino then outputs a sinusoidal value. The Arduino’s output is amplified and applied to the coil on the CRT. A network of power resistors ensures the amplifier is correctly loaded. The results speak for themselves. In the video after the break, the tube flag is displaying a slide show of photographs of its construction. As an added hack, [Gijs] used an Arduino Leonardo as a USB keyboard. When the anemometer spins, the primary ATmega328 sends a signal to the Leonardo, which then emulates a push of the arrow keys on the host computer. This lets the tube flag advance its own images. Very cool work indeed!

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The 30th Anniversary Macintosh

SE

It’s been just over thirty years since the original Macintosh was released, and [hudson] over at NYC Resistor thought it would be a good time to put some old hardware to use. He had found an all-in-one Mac SE “on the side of a road” a while ago (where exactly are these roads, we wonder), and the recent diamond anniversary for the original mac platform convinced him to do some major hardware hacking.

Inspired by a six-year-old project from a NYC Resistor founder aptly named the 24th anniversary Mac, [hudson] decided to replace the old hardware with more powerful components – in this case, a BeagleBone Black. Unlike the earlier build, though, the original CRT would be salvaged; the analog board on the Mac SE has pins for video, hsync, vsync, and power.

To get a picture on the old CRT, [hudson] needed to write a software video card that used the BeagleBone’s PRU. The CRT isn’t exactly “modern” tech, and everything must be clocked at exactly 60.1 Hz lest the CRT emit a terrible buzzing sound.

With a software video card written for the old CRT, the BeagleBone becomes the new brains of this beige box. It runs all the classic Linux GUI apps including XEyes and XScreenSaver, although flying toasters might be out of the question. He also managed to load up the Hackaday retro site with xterm, making this one of the best ways to make an old Mac SE useful.

Retrotechtacular: Cathode Ray Tube (CRT) Manufacturing

retrotechtacular-crt-manufacturing

This week we return to the grainy and un-color-corrected goodness that is synonymous with ancient video reels. [CNK] sent in a tip to a set of videos showing how Cathode Ray Tubes are manufactured on a massive scale. You’ll want to watch the pair of clips embedded below which total about 18 minutes. But there’s also some background to be found at this post from the Obsolete Technology Telley Web Museum.

The video presentation starts off with a brief overview of the way a color CRT works. It then moves to a factory tour, carefully showing each step in the process. The footage was shot in the 1960′s and because of that we catch a glimpse of some vintage equipment, like that used to measure the curvature of the CRT glass. You may be thinking that the world of CRT is in the past, but not so. We think there may even been a coming fad of producing them in your home lab.

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The Tiniest Video Game

stamp

As we read [Adam]‘s writeup for an extremely tiny video game system through coke bottle glasses, we’re reminded of the countless times we were told that sitting, ‘too close to the Nintendo’ would ruin our eyes. We’ll happily dismiss any article from a medical journal that says there was any truth to that statement, but [Adam]‘s tiny video game system will most certainly hurt your eyes.

A few years ago, Atari sold keychain-sized joysticks that contained classics such as PongBreakout, Centipede, and Asteroids. [Adam] apparently ran into a cache of these cool classic baubles and immediately thought of turning them into a stand-alone video game system.

For the display, [Adam] used a CRT module from an old Sony Handicam. These modules had the right connections – power, ground, and composite video input – to connect directly to the Atari keychain games. The result is a video game that’s even smaller than a postage stamp. The picture above shows the tiny CRT next to a 25mm postage stamp; it’s small by any measure.

A Retro, Not Steampunk, Media Center

turn

[toddfx] wanted to put his Raspberry Pi to work and set about creating one of the best stereos we’ve ever seen: It’s called the Audio Infuser 4700, and turns a conglomeration of old disused stereo equipment into a functional piece of art.

[toddfx] used a Raspberry Pi to stream music over WiFi, but also wanted to play some classic vinyl. He took apart an old Yamaha YP-D4 turntable. stripped it to the bone, and created a fantastic oak enclosure around it. To this, he added a seven-band graphic EQ, aux jacks (both in and out), and a tiny 5″ CRT from an old portable TV.

Where this build really gets great is the fabrication. The front panels have all their graphics and lettering engraved via a toner-transfer like method using copper sulphate and salt. [todd] got the idea from this thread and we have to say the results are unbelievable.

Even though this awesome device only used for music, [toddfx] used the tiny color CRT to its fullest. Flick one switch, and it’s an oscilloscope-like display. Flick another switch, and it’s the output of the Raspberry Pi loaded up with a few MAME games including Pacman, Asteroids, and Space Invaders.

[toddfx] put up a build page for his Audio Infuser and an awesome video for his project, available below.

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Bench equipment tip: Screenshot of old oscilloscopes

oscillocam-oscilloscope-camera-accessory

Here’s a quick tip on capturing the output of oscilloscopes that don’t have that native feature. [Paulo Renato] used a cookie tin as a camera cowl for capturing CRT oscilloscope screenshots.

We figure if you’ve got any kind of functioning oscilloscope you’re lucky. And although it’s nice to pull down the measurements to your PC on the newer models, the results [Paul] gets with this rig are still satisfactory. The plastic cookie box he used blocks out ambient light while holding the camera at a consistent focal length. He used some flat black spray paint to make sure the obnoxious yellow plastic didn’t interfere with the image, then drilled a hole which fits tightly around his camera lens.

You’ll need to monkey with the exposure settings to get the best image. But once you’ve got it dialed in it should be the same every time you want to take a picture of the screen.