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The box of the Busch Electronic Digital-Technik 2075

The Busch Electronic Digital-Technik 2075 Digital Lab From The 1970s

November 26, 2025 by 2 Comments

In a recent video, [Jason Jacques] demos the Busch Electronic Digital-Technik 2075 which was released in West Germany in the 1970s.

The Digital-Technik 2075 comes with a few components including a battery holder and 9 V battery, a push button, two 1 K resistors, a red LED, a 100 nF ceramic capacitor, a 100 µF electrolytic capacitor, a quad NAND gate IC, and a counter module which includes an IC and a 7-segment display. The kit also comes with wires, plugs, a breadboard, and a tool for extracting modules.

The Digital-Technik 2075 doesn’t use the spring terminals we see in other project labs of the time, such as the Science Fair kits from Radio Shack, and it doesn’t use modular Denshi blocks, such as we saw from the Gakken EX-150, but rather uses wire in conjunction with yellow plastic plugs. This seems to work well enough.

In the video, after showing us how to do switch debouncing, [Jason] runs us through making a counter with the digital components and then getting the counter to reset after it counts to five. This is done using NAND gates. Before he gets stuck into doing a project he takes a close look at the manual (which is in German) including some of the advertisements for other project labs from Busch which were available at the time. As he doesn’t speak German [Jason] prints out an English translation of the manual before working through it.

We’ve heard from [Jason] at Hackaday in recent history when we saw his Microtronic Phoenix Computer System which referenced the 2090 Microtronic Computer System which was also made by Busch.

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DIY Test Gear From 1981

November 25, 2025 by 2 Comments

We can’t get enough of [Bettina Neumryn’s] videos. If you haven’t seen her, she takes old electronics magazines, finds interesting projects, and builds them. If you remember these old projects, it is nostalgic, and if you don’t remember them, you can learn a lot about basic electronics and construction techniques. This installment (see below) is an Elektor digital voltmeter and frequency counter from late 1981.

As was common in those days, you could find the PCB layouts in the magazine. In this case, there were two boards. The schematic shows that a counter and display driver chip — a 74C928 — does most of the heavy lifting for the display and the counter.

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Build Yourself A Medium-Format Camera

November 24, 2025 by 4 Comments

Medium format cameras have always been a step up from those built in the 35 mm format. By virtue of using a much larger film, they offer improved resolution and performance. If you want a medium format film camera, you can always hunt for some nice vintage gear. Or, you could build one from scratch — like the MRF2 from [IDENTIDEM.design.]

The MRF2 might be a film camera, but in every other way, it’s a thoroughly modern machine. It’s a rangefinder design, relying on a DTS6012M LIDAR time-of-flight sensor to help ensure your shots are always in sharp focus. An ESP32 is responsible for running the show, and it’s hooked up to OLED displays in the viewfinder and on the body to show status info. The lens is coupled with a linear position sensor for capturing accurate shots, there’s a horizon indicator in the viewfinder, and there’s also a nice little frame counter using a rotary encoder to track the film.

Shots from a prototype on Instagram show that this camera can certainly pull off some beautiful shots. We love a good camera build around these parts. You can even make one out of a mouse if you’re so inclined.

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Pong Gets The Boot

November 20, 2025 by 5 Comments

You might be surprised to find out that [Akshat Joshi’s] Pong game that fits in a 512-byte boot sector isn’t the first of its kind. But that doesn’t mean it isn’t an accomplishment to shoehorn useful code in that little bitty space.

As you might expect, a game like this uses assembly language. It also can’t use any libraries or operating system functions because there aren’t any at that particular time of the computer startup sequence. Once you remember that the bootloader has to end with two magic bytes (0x55 0xAA), you know you have to get it all done in 510 bytes or less.

This version of Pong uses 80×25 text mode and writes straight into video memory. You can find the code in a single file on GitHub. In the old days, getting something like this working was painful because you had little choice but reboot your computer to test it and hope it went well. Now you can run it in a virtual machine like QEMU and even use that to debug problems in ways that would have made a developer from the 1990s offer up their life savings.

We’ve seen this before, but we still appreciate the challenge. We wonder if you could write Pong in BootBasic?

Screen-Accurate Lightsaber As A Practical Effect

November 7, 2025 by 18 Comments

The lightsaber was one of the coolest and most iconic visual effects from the original Star Wars, and people have been trying to get that particular piece of movie magic off the silver screen for about 40 years now. [HeroTech] seems to have cracked the code with their “Impossible Lightsaber”— it’s fully retractable, fully lit, and able to hit things (lightly), all while fitting into a replica prop handle.

The secret is… well, there’s more than one secret, here. The blade itself is made out of a “magician’s cane”, which is a coil of plastic that can spring outwards on demand for magic tricks. Hidden inside of it is a strip of LED lights. Of course one strip of LEDs would not be omnidirectional, and the magician’s cane is pretty floppy, but both of those problems are solved by the same idea: “I’ll try spinning. That’s a good trick.”

The spin-stabilized blade holds up to being waved around much better, and apparently the gyroscopic forces it induces are actually lore-accurate. (Who knew?) Of course fitting a motor to spin the “blade”, and another to winch it back in, along with the circuitry and batteries to drive them was no mean feat. It’s impressive they fit it all inside the replica handle; even more impressive that they fit a speaker so this prop even makes the iconic sound effects. We always wanted to see a stage production of William Shakespeare’s Star Wars, and this gives us verily, a new hope.

[HeroTech] isn’t done yet– while seemingly impossible, this lightsaber isn’t perfect, as it’s not rugged enough for full dueling. It’s also not easy to put together, and apparently can’t handle the delicate attentions of airline baggage handlers. So ruggedization and a bit of design-for-assembly are on the table for the next version. Sadly the project is not open source; they are releasing the build files to subscribers only. Given how much work must have gone into iterating to get to this point, that is disappointing, but understandable. Everybody needs to make a living, after all.

If this project seems familiar, it’s because we featured a much-bulkier previous iteration last year.

You may prefer your lightsabers to match the movie version in effects instead of visuals; if that’s the case, check out this saber that uses HHO to cut through a steel door.

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Pi-Powered Camera Turns Heads And Lenses In Equal Measure

November 7, 2025 by 11 Comments

Have you ever seen photos of retro movie sets where the cameras seem to be bedazzled with lenses? Of course you can only film via one lens at a time, but mounting multiple lenses on a turret as was done in those days has certain advantages –particularly when working with tiny M12 lenses, like our own [Jenny List] recently did with this three-lens, Pi-zero based camera.

Given that it’s [Jenny], the hardware is truly open source, with not just the Python code to drive the Pi but the OpenSCAD code used to generate the STLs for the turret and the camera body all available via GitHub under a generous CC-BY-SA-4.0 license. Even using a cheap sensor and lenses from AliExpress, [Jenny] gets good results, as you can see from the demo video embedded below. (Jump to 1:20 if you just want to see images from the camera.)

The lenses are mounted to a 3D printed ring with detents to lock each quickly in place, held in place by a self-tapping screw, proving we at Hackaday practice what we preach. (Or that [Jenny] does, at least when it comes to fasteners.) Swapping lenses becomes a moment’s twist, as opposed to fiddling with tiny lenses hoping you don’t drop one. We imagine the same convenience is what drove turret cameras to be used in the movie industry, once upon a time.

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Volumetric Display Takes A Straight Forward (and Backward) Approach

November 1, 2025 by 11 Comments

There’s something delightfully sci-fi about any kind of volumetric display. Sure, you know it’s not really a hologram, and Princess Leia isn’t about to pop out and tell you you’re her only hope, but nothing says “this is the future” like an image floating before you in 3D. [Matthew Lim] has put together an interesting one, using persistence-of-vision and linear motion.

The basic concept is so simple we’re kind of surprised we don’t see it more often. Usually, POV displays use rotary motion: on a fan, a globe, a disk, or even a drone, we’ve seen all sorts of spinning LEDs tricking the brain into thinking there’s an image to be seen. [Matthew’s] is apparently the kind of guy who sticks to the straight-and-narrow, on the other hand, because his POV display uses linear motion.

An ESP32-equipped LED matrix module is bounced up by an ordinary N20 motor that’s equipped with an encoder and driven by a DRV8388. Using an encoder and the motor driver makes sure that the pixels on the LED matrix are synced perfectly to the up-and-down motion, allowing for volumetric effects. This seems like a great technique, since it eliminates the need for slip rings you might have with rotary POV displays. It does of course introduce its own challenges, given that inertia is a thing, but I think we can agree the result speaks for itself.

One interesting design choice is that the display is moved by a simple rack-and-pinion, requiring the motor to reverse 16 times per second. We wonder if a crank wouldn’t be easier on the hardware. Software too, since [matthew] has to calibrate for backlash in the gear train. In any case, the stroke length of 20 mm creates a cubical display since the matrix is itself 20 mm x 20 mm. (That’s just over 3/4″, or about twice the with of a french fry.) In that 20 mm, he can fit eight layers, so not a great resolution on the Z-axis but enough for us to call it “volumetric” for sure. A faster stroke is possible, but it both reduces the height of the display and increases wear on the components, which are mostly 3D printed, after all.

It’s certainly an interesting technique, and the speechless (all subtitles) video is worth watching– at least the first 10 seconds so you can see this thing in action.

Thanks to [carl] for the tip. If a cool project persists in your vision, do please let us know. Continue reading “Volumetric Display Takes A Straight Forward (and Backward) Approach” →