Author: Jenny List

3059 Articles

The Future We Never Got, Running A Future We Got

March 6, 2025 by 39 Comments

If you’re familiar with Java here in 2025, the programming language you know is a world away from what Sun Microsystems planned for it in the mid-1990s. Back then it was key to a bright coffee-themed future of write-once-run-anywhere software, and aside from your web browser using it to run applications, your computer would be a diskless workstation running Java bytecode natively on the silicon.

What we got was slow and disappointing Java applets in web pages, and a line of cut-down SPARC-based JavaStations which did nothing to change the world. [FatSquirrel] has one of these machines, and a quarter century later, has it running NetBSD. It’s an interesting journey both into 1990s tech, and some modern-day networking tricks to make it happen.

These machines suffer as might be expected, from exhausted memory backup batteries. Fortunately once the serial port has been figured out they drop you into an OpenBoot prompt, which, in common with Apple machines in the ’90s, gives you a Forth interpreter. There’s enough info online to load the NVRAM with a config, and the machine stuttered into life. To do anything useful takes a network with RARP and NFS to serve an IP address and disk image respectively, which a modern Linux machine is quite happy to do. The resulting NetBSD machine maybe isn’t as useful as it could be, but at risk of angering any Java enthusiasts, perhaps it’s more useful than the original JavaOS.

We remember the promise of a Java-based future too, and tasted the bitter disappointment of stuttering Java applets in our web pages. However, given that so much of what we use now quietly runs Java in the background without our noticing it, perhaps the shade of Sun Microsystems had the last laugh after all. This isn’t the first ’90s machine that’s been taught new tricks here, some of them have received Java for the first time.

A TV With Contrast You Haven’t Seen For Years

March 5, 2025 by 42 Comments

It’s something of a surprise, should you own a CRT TV to go with your retrocomputers, when you use it to view a film or a TV show. The resolution may be old-fashioned, but the colors jump out at you, in a way you’d forgotten CRTs could do. You’re seeing black levels that LCD screens can’t match, and which you’ll only find comparable on a modern OLED TVs. Can an LCD screen achieve decent black levels? [DIY Perks] is here with a modified screen that does just that.

LCD screens work by placing a set of electronic polarizing filters in front of a bright light. Bright pixels let through the light, while black pixels, well, they do their best, but a bit of light gets through. As a result, they have washed-out blacks, and their images aren’t as crisp and high contrast as they should be. More modern LCDs use an array of LEDs as the backlight which they illuminate as a low resolution version of the image, an approach which improves matters but leaves a “halo” round bright spots.

The TV in the video below the break is an older LCD set, from which he removes the backlight and places the electronics in a stand. He can show an image on it by placing a lamp behind it, but he does something much cleverer. An old DLP projector with its color wheel removed projects a high-res luminance map onto the back of the screen, resulting in the coveted high contrast image. The final result uses a somewhat unwieldy mirror arrangement to shorten the distance for the projector, but we love this hack. It’s not the first backlight hack we’ve seen, but perhaps it give the best result.

Continue reading “A TV With Contrast You Haven’t Seen For Years” →

Is This The Oldest HD Video Online?

March 5, 2025 by 35 Comments

Take a look at this video from [Reely Interesting], showing scenes from traditional Japanese festivals. It’s well filmed, and as with any HD video, you can see real detail. But as you watch, you may see something a little out of the ordinary. It’s got noise, a little bit of distortion, and looking closely at the surroundings, it’s clearly from the 1980s. Something doesn’t add up, as surely we’d expect a video like this to be shot in glorious 525 line NTSC. In fact, what we’re seeing is a very rare demo reel from 1985, and it’s showing off the first commercial HDTV system. This is analogue video in 1035i, and its background as listed below the video makes for a very interesting story.

Most of us think of HDTV arriving some time in the 2000s when Blu-ray and digital broadcasting supplanted the NTSC or PAL systems. But in fact the Japanese companies had been experimenting since the 1960s, and these recordings are their first fruits. It’s been digitized from a very rare still-working Sony HDV-1000 reel-to-reel video recorder, and is thus possibly the oldest HD video viewable online. They’re looking for any HDV-1000 parts, should you happen to have one lying around. Meanwhile, the tape represents a fascinating window into a broadcast history very few of us had a chance to see back in the day.

This isn’t the first time we’ve touched on vintage reel-to-reel video.

Continue reading “Is This The Oldest HD Video Online?” →

Build A Parametric Speaker Of Your Own

March 4, 2025 by 16 Comments

The loudspeaker on your home entertainment equipment is designed to project audio around the space in which it operates, if it’s not omnidirectional as such it can feel that way as the surroundings reflect the sound to you wherever you are. Making a directional speaker to project sound over a long distance is considerably more difficult than making one similar to your home speaker, and [Orange_Murker] is here with a solution. At the recent Hacker Hotel conference in the Netherlands, she presented an ultrasonic parametric speaker. It projects an extremely narrow beam of sound over a significant distance, but it’s not an audio frequency speaker at all.

Those of you familiar with radio will recognize its operation; an ultrasonic carrier is modulated with the audio to be projected, and the speaker transfers that to the air. Just like the diode detector in an old AM radio, air is a nonlinear medium, and it performs a demodulation of the ultrasound to produce an audio frequency that can be heard. She spends a while going into modulation schemes, before revealing that she drove her speaker with a 40 kHz PWM via an H bridge. The speaker itself is an array of in-phase ultrasonic transducers, and she demonstrates the result on her audience.

This project is surprisingly simple, should you wish to have a go yourself. There’s a video below the break, and she’s put all the files in a GitHub repository. Meanwhile this isn’t the first time we’ve seen a project like this.

Continue reading “Build A Parametric Speaker Of Your Own” →

It’s 2025, And Here’s A New Film Format

March 4, 2025 by 8 Comments

We love camera hacking here at Hackaday, and it’s always fascinating to see new things being done in photography. Something rather special has come our way from [Camerdactyl], who hasn’t merely made a camera, instead he’s created an entirely new analogue film format. Move over 35mm and 120, here’s the RA-4 cartridge!

RA-4 is the colour print chemistry many of you will be familiar with from your holiday snaps back in the day. Normally a negative image is projected onto it from the negative your camera took, and the positive image is developed on the paper as the reverse of that.  It can also be developed as a reversal process similar to slide film, in which the negative image is developed and bleached away leaving an unexposed positive image, which can then be exposed to light and developed to reveal a picture. This means that with carefully chosen colour correction filters it can be shot in a camera to make normal colour prints with this reversal process.

The new film format is a 3D printed cartridge system holding a long roll of RA-4 paper, which slots into a back for standard 5 by 4 inch cameras. He’s also made a modular developing machine for the process, and can get over 100 shots on a roll. A portion of the video below deals with how he wants to release it; since it has taken a huge amount of development resources he intends to release the files to the public in stages as he reaches sales milestones with his work. It’s an unusual strategy that we hope works for him, though we suspect that many camera hackers would be prepared to pay him directly for the files.

Either way, it’s a reminder that there’s still plenty of fun to be had with analogue film, and also that reversal development of RA-4 is possible. Some of us here at Hackaday have been known to hack a few cameras, we guess it’s another one to add to the “one day” list.

Continue reading “It’s 2025, And Here’s A New Film Format” →

It’s SSB, But Maybe Not Quite As You Know It

March 3, 2025 by 17 Comments

Single Sideband, or SSB, has been the predominant amateur radio voice mode for many decades now. It has bee traditionally generated by analogue means, generating a double sideband and filtering away the unwanted side, or generating 90 degree phase shifted quadrature signals and mixing them. More recent software-defined radios have taken this into the CPU, but here’s [Georg DG6RS] with another method. It uses SDR techniques and a combination of AM and FM to achieve polar modulation and generate SSB. He’s provided a fascinating in-depth technical explanation to help understand how it works.

The hardware is relatively straightforward; an SI5351 clock generator provides the reference for an ADF4351 PLL and VCO, which in turn feeds a PE4302 digital attenuator. It’s all driven from an STM32F103 microcontroller which handles the signal processing. Internally this means conventionally creating I and Q streams from the incoming audio, then an algorithm to generate the phase and amplitude for polar modulation. These are fed to the PLL and attenuator in turn for FM and AM modulation, and the result is SSB. It’s only suitable for narrow bandwidths, but it’s a novel and surprisingly simple deign.

We like being presented with new (to us at least) techniques, as it never pays to stand still. Meanwhile for more conventional designs, we’ve got you covered.

Bringing A Current Dumping Amplifier Back To Life

February 27, 2025 by 9 Comments

Over the years there have been many different audio amplifier designs which have found favour for a while and then been supplanted by newer ideas. One of them has crossed the bench of [Jazzy Jane], it’s a current dumping amplifier from the mid-1980s. A nicely-done home-made project on stripboard mounted on a wooden base board, it sports a power supply, RIAA pre-amp board, and the amplifier itself.

The current dumping amplifier is one that combines a small class A amplifier with a hefty class B one, and through feedback trickery uses the combination to remove the crossover distortion of the class B stage. It’s a simple yet elegant circuit with fewer parts than an equivalent class AB amplifier, and there was a time back in the day when it was all the rage. This one has an op-amp providing the class A part and a complimentary pair of Darlington pairs as the class B.

The video below the break shows the process of bringing the amp back to life, a process mostly concerned with the power supply. There are a set of tantalum capacitors which have failed, and the replacements she’s using turn out to have problems too. They’re a period part for a project of this age, but we might have been tempted to go for another capacitor type here.

The result is an unusual amplifier, brought back to life. You may have seen [Jane] feature here before, with her 1950s signal generator.

Continue reading “Bringing A Current Dumping Amplifier Back To Life” →