If you’re a photography enthusiast, you probably own quite a few cameras, but the chances are your “good” one will have interchangeable lenses. Once you’ve exhausted the possibilities of the kit lens, you can try different focal lengths and effects, but you’ll soon find out that good glass isn’t cheap. Can you solve this problem by making your own lenses? [Billt] has done just that.

Given some CAD skills, it’s possible to replicate the mount on an existing lens, but he takes a shortcut by using a readily available camera cap project. There are two lenses detailed in the video below the break; the first is a plastic lens from a disposable camera, while the second takes one from a Holga toy camera. The plastic lens is inserted mid-print, giving the colour aberrations and soft focus you’d expect, while the Holga lens is mounted on a slide for focusing. There may be some room for improvement there, but the result is a pair of fun lenses for experimentation for not much outlay. Given the number of broken older cameras out there, it should be relatively easy for anyone wanting to try this for themselves to have a go.

The video is below the break, but while you’re on this path, take a look at a previous project using disposable camera lenses. Or, consider printing an entire camera.

As consumers worldwide slowly make the switch from internal combustion vehicles to lower-carbon equivalents, a few concerns have appeared about electric vehicles. Range anxiety is ebbing away as batteries become bigger and chargers become more frequent, but a few well-publicized incidents have raised worries over fire safety.

Lithium-ion batteries can ignite in the wrong circumstances, and when they do so they are extremely difficult to extinguish. Renault has a solution, and in a rare moment for the car industry, they are sharing it freely for all manufacturers to use.

The innovation in question is their Fireman Access Port, a standardized means for a fire crew to connect up their hoses directly to the battery pack and attack the fire at its source. An opening is covered by an adhesive disk designed to protect the cells, but breaks under a jet of high-pressure water. Thermal runaway can then be halted much more easily.

The licensing terms not only allow use of the access port itself, but also require any enhancements be shared with the rest of the community of automakers using the system. This was the part which caught our interest, because even if it doesn’t come from the same place as the licences we’re used to, it sounds a lot like open source to us.

Oddly, this is not the first time Renault have open-sourced their technology, in the past they’ve shared an entire car.

Many of us use touch pads daily on our laptops, but rarely do we give much thought about what they really do. In fact they are a PCB matrix of conductive pads, with a controller chip addressing it and sensing the area of contact. Such a complex and repetitive pattern can be annoying to create by hand in an EDA package, so [Timonsku] has written a script to take away the work.

It starts with an OpenSCAD script (originally written by Texas Instruments, and released as open source) that creates a diamond grid, which can be edited to the required dimensions and resolution. This is then exported as a DXF file, and the magic begins in a Python script. After adjustment of variables to suit, it finishes with an Eagle-compatible board file which should be importable into other EDA packages.

We’ve never made a touchpad ourselves, but having dome other such repetitive PCB tasks we feel the pain of anyone who has. Looking at this project we’re struck by the thought that its approach could be adapted for other uses, so it’s one to file away for later.

This isn’t the first home-made touchpad project we’ve brought you.

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.

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.

Thanks [Keith Olson] for the tip!

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.

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.

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.

QR codes have been with us for a long time now, and after passing through their Gardenesque hype cycle of inappropriate usage, have now settled down to be an important and ubiquitous part of life. If you have ever made a QR code you’ll know all about trying to generate the most compact and easily-scannable one you can, and for that [Terence Eden] is here with an interesting quirk. Upper-case text produces smaller codes than lower-case.

His post takes us on a journey into the encoding of QR codes, not in terms of their optical pattern generation, but instead the bit stream they contain. There are different modes to denote different types of payload, and in his two examples of the same URL in upper- and lower- cases, the modes are different. Upper-case is encoded as alphanumeric, while lower-case, seemingly though also containing alphanumeric information, is encoded as bytes.

To understand why, it’s necessary to consider the QR codes’ need for efficiency, which led its designers to reduce their character set as far as possible and only define uppercase letters in their alphanumeric set. The upper-case payload is thus encoded using less bits per character than the lower-case one, which is encoded as 8-bit bytes. A satisfying explanation for a puzzle in plain sight.

Hungry for more QR hackery? This one contains more than one payload!

Making a multi-band amateur radio transceiver has always been a somewhat challenging project, and making one that also supported different modes would for many years have been of almost impossible complexity best reserved for expensive commercial projects. [Bob W7PUA] has tackled both in the form of a portable 10-band multi-mode unit, and we can honestly say he’s done a very good job indeed.

As you might expect in 2025 it’s a software defined radio (SDR), but to show how powerful the silicon available today is, it’s all implemented on a microcontroller. There’s a Teensy 4 with an audio codec board that does all the signal processing heavy lifting, and an RF board that takes care of the I/Q mixing and the analogue stuff.

Band switching is handled using a technique from the past; interchangeable plug-in coil and filter units, that do an effective job. The result is a modestly-powered but extremely portable rig that doesn’t look to have broken the bank, and since the write-up goes into detail on the software side we hope it might inform other SDR projects too. We might have gone for old-school embossed Dymo labels on that brushed aluminium case just for retro appeal, but we can’t fault it.

It’s not the first time we’ve looked at a small multi-band SDR here, but we think this one ups the game somewhat.

Thanks [Pete] for the tip!

In the decade or more since small inexpensive Linux-capable single board computers such as the Raspberry Pi came to the mainstream, many a hardware hacker has turned their attention to making a portable computer using one. With such a plethora of devices having been made one might think that the Pi handheld was a done deal, but every so often along comes a new one of such quality to re-ignite the genre. So it is with [Taylor Hay]’s BlackberryPi Handheld. As you might guess from the name, it uses a BlackBerry keyboard along with a square LCD screen to create a beautifully executed Pi handheld in an almost GameBoy-like form factor.

It starts with a beautifully designed and executed case that holds a Pi and a Pimoroni HyperPixel screen. Unexpectedly this is a full-size Pi, we think a Pi 4. The keyboard is a USB enhanced Blackberry module which also has the famous trackpad, and there’s a bezel on the front to protect the screen. The power meanwhile comes from three 18650 cells inside the back of the case, with a power bank PCB. The surprise here is how simple he’s made it by careful choice of modules, the usual rats-nest of wires is missing.

The files are available so you can make your own, and he’s actively encouraging people to remix and improve it. We like this project, a lot, and after you’ve seen the video below the break, we think you will too. Oddly, this isn’t the first time we’ve seen someone try this combination.

Instant photography occupies a niche in film photography that has endured despite its relatively high cost and the ease of newer digital technologies. There are two main manufacturers, Polaroid and Fujifilm, as well as a few smaller boutique camera makers. Into this comes [Toast], with an entirely 3D printed instant camera, not a Polaroid as he calls it, but one for Fuji Instax Mini film.

Currently available instant film comes in cartridges in which each picture is a layered design with a sachet of developing chemicals at the end. Once the film part has been exposed it is developed by passing through a set of rollers which squeeze the chemicals evenly over the film, allowing it to develop. The camera in the video below the break is simple enough, a pinhole box camera design, but the huge challenge and the interesting part of the video comes in the developer attachment which has those rollers. It’s considerably more challenging than it might at first appear, and he goes through many iterations before getting it right with some steel rollers.

The 3D print files are available but only at a price, and despite that we think there’s enough in the video below for anyone who wants to experiment for themselves. For the rest of us it’s an insight into a technology we all know about, but maybe have never looked closely at.

Instax has appeared here before, usually as an instant back for older cameras, but sometimes for far tastier projects.

Turning surplus LCD panels into stand-alone monitors with the help of a driver board is an established hack, and a search of eBay or AliExpress will turn up boards for almost any widely available panel. [Drygol] has a couple of old iPad screens, and has done exactly this with them. What makes these two projects stand aside from the crowd is their attention to detail, instead of creating a hacky monitor this is almost something you might buy as a product.

For a start, both screens sit in very smart 3D printed cases. Behind them is the LCD driver, and perhaps this is where many people might leave it. But the point of an iPad is portability, so the first one receives a suitably large lithium polymer battery and its associated electronics. As such a thing is of limited use without a battery level monitor, so one is mounted flush with the case on the outside. The final touch is a Bluetooth audio board and speaker, making an all-in-one peripheral we’d be happy to carry with us.

The second screen is a slimmer version of the first case, with a different board that has an onboard audio channel. It’s mounted in a stand with a MiSter FPGA emulator, for a very neat and compact desktop set-up.

This project shows what can be done with these screens, and raises the bar. All the files are included, so it should be possible to make your own. We expect someone might stick a Raspberry Pi in there, to make… something like an iPad.

This isn’t the first time we’ve seen an iPad screen mod.

In 1997 a set of DEC tapes were provided by Dennis Ritchie, as historical artifacts for those interested in the gestation of the UNIX operating system. The resulting archive files have recently been analysed by [Yfeng Gao], who has succeeded in recovering a working UNIX version from 1972. What makes it particularly interesting is that this is not a released version, instead it’s a work in progress sitting somewhere between versions 1 and 2. He’s therefore taken the liberty of naming it “V2 Beta”.

If you happen to have a PDP-11/20 you should be able to run this operating system for yourself, and for those of us without he’s provided information on which emulator will work. The interesting information for us comes in the README accompanying the tapes themselves, and in those accompanying the analysis. Aside from file fragments left over from previous users of the same tape, we learn about the state of UNIX time in 1972. This dates from the period when increments were in sixtieths of a second due to the ease of using the mains power frequency in a PDP, so with a 32-bit counter they were facing imminent roll-over. The 1970-01-01 epoch and one second increments would be adopted later in the year, but meanwhile this is an unusual curio.

If you manage to run this OS, and especially if you find anything further in the files, we’d love to hear. Meanwhile, this is not the oldest UNIX out there.

PDP-11/20 image: Don DeBold, CC BY 2.0.

Vacuum forming is perhaps one of the less popular tools in the modern maker arsenal, something which surprises us a bit because it offers many possibilities. We’ve created our own vacuum forms on 3D printed moulds for ages, so it’s interesting to see [Pisces Printing ] following the same path. But what you might not realize at first is that the vacuum forming sheets themselves are also 3D printed.

The full video is below the break, and in it he details making a mould from PETG, and in particular designing it for easy release. The part he’s making is a belt guard for a table top lathe, and the PETG sheet he’s forming it from is also 3D printed. He makes the point that it’s by no means perfect, for example he shows us a bit of layer separation, but it seems promising enough for further experimentation.  His vacuum forming setup seems particularly small, which looks as though it makes the job of making a sheet somewhat simpler.

The cost of a vacuum forming sheet of whichever polymer is hardly high, so we can’t see this technique making sense for everyday use. But as we’ve seen in previous experiments, the printed sheets so make it easy to add color and texture to the final product, which obviously adds some value to the technique.

Thanks [Tomas Harvie Mudrunka] for the tip.

Rev up your browsers, package managers, or whatever other tool you use to avail yourself of new software releases, because the KiCAD team have announced that barring any major bugs being found in the next few hours, tomorrow should see the release of version 9 of the open source EDA suite. Who knows, depending on where you are in the world that could have already happened when you read this.

Skimming through the long list of enhancements brought into this version there’s one thing that strikes us; how this is now a list of upgrades and tweaks to a stable piece of software rather than essential features bringing a rough and ready package towards usability. There was a time when using KiCAD was a frustrating experience of many quirks and interface annoyances, but successive versions have improved it beyond measure. We would pass comment that we wished all open source software was as polished, but the fact is that much of the commercial software in this arena is not as good as this.

So head on over and kick the tires on this new KiCAD release, assuming that it passes those final checks. We look forward to the community’s verdict on it.

[Michael Wessel] found some of his old DOS 3D graphics software and tried to run it on an 8088 PC. The tale of adding an 8087 co-processor to speed up the rendering was anything but straightforward, resulting in a useful little project.

There was a point around the end of the 1980s when the world of PCs had moved on to the 386, but the humble 8086 and 8088 hung around at the consumer end of the market. For Europeans that meant a variety of non-standard machines with brand names such as Amstrad and Schneider, and even surprisingly, later on Sinclair and Commodore too.

Of these the Schneider Euro PC was an all-in-one design reminiscent of an Amiga or Atari ST, packing a serviceable 8088 PC with a single 3.5″ floppy drive. A cheap machine like this was never thought to need an 8087, and lacked the usual socket on the motherboard, so he made a small PCB daughter board for the 8088 socket with space for both chips.

It’s a surprisingly simple circuit, as obviously the two chips were meant to exist together. It certainly had the desired effect on his frame rate, though we’re not sure how many other Euro PC users will need it. It does make us curious though, as to how quickly a modern microcontroller could emulate an 8087 for an even faster render time. Meanwhile if you’re curious about the 8087, of course [Ken Shirriff] has taken a look at it.

The world of computer enthusiasts has over time generated many subcultures and fandoms, each of which has in turn spawned its own media. [Intric8] has shared the tale of his falling down a rabbit hole as he traced one of them, a particularly esoteric disk magazine for the Commodore 64. The disks are bright yellow, and come with intricate home-made jackets and labels. Sticking them into a 1541 drive does nothing, because these aren’t standard fare, instead they require GEOS and a particularly upgraded machine. They appear at times in Commodore swap meets, and since they formed a periodical there are several years’ worth to collect that extend into the 2000s, long after the heyday of the 64.

Picking up nuggets of information over time, he traces them to Oregon, and the Astoria Commodore User Group, and to [Lord Ronin], otherwise known as David Mohr. Sadly the magazine ended with his death in 2009, but until then he produced an esoteric selection of stories, adventure games, and other software for surely one of the most exclusive computer clubs in existence. It’s a fascinating look into computer culture from before the Internet, even though by 2009 the Internet had well and truly eclipsed it, when disks like these were treasured for the information they contained. So if you find any of these yellow Penny Farthing disks, make sure that they or at least their contents are preserved.

Surprisingly, this isn’t the only odd format disk magazine we’ve seen.

Typography enthusiasts reach a point at which they can recognise a font after seeing only a few letters in the wild, and usually identify its close family if not the font itself. It’s unusual then for a font to leave them completely stumped, but that’s where [Marcin Wichary] found himself. He noticed a font which many of you will also have seen, on typewriter and older terminal keys. It has a few unusual features that run contrary to normal font design such as slightly odd-shaped letters and a constant width line, and once he started looking, it appeared everywhere. Finding its origin led back well over a century, and led him to places as diverse as New York street furniture and NASA elevators.

The font in question is called Gorton, and it came from the Gorton Machine Co, a Wisconsin manufacturer. It’s a font designed for a mechanical router, which is why it appears on so much custom signage and utilitarian components such as keyboard keys. Surprisingly its history leads back into the 19th century, predating many of the much more well-know sans serif fonts. So keep an eye out for it on your retro tech, and you’ll find that you’ve seen a lot more of it than you ever knew. If you are a fellow font-head, you might also know the Hershey Font, and we just ran a piece on the magnetic check fonts last week.

Thanks [Martina] for the tip!