6502 based laptop

Retro Rover: LT6502 Laptop Packs 8-Bit Power On The Go

February 17, 2026 by 4 Comments

Making your own laptop can be a challenging project, but a doable one, especially given the large number of options available today for computing. Of course nothing says you need to use a modern component in your build, and in the LT6502 project by [TechPaula] they didn’t go with a modern RPi or the like, nope went right back to about 50 years ago to use a 6502 at the heart of this DIY laptop build.

The 6502 is an 8-bit microprocessor from the 1970s, found in the Commodore 64 and Apple II. This wasn’t their first venture into 8 MHz world of the 6502, prior to this laptop build there was a desktop build the PC6502 bringing this chip of old into a PC/104 form factor. The LT6502 adds in the things you’d expect with a laptop, a 9-inch foldable screen, a 10,000 mAh battery, several external ports for things such as serial console and USB-C charging. A custom keyboard adds in low-profile switches as well as including a HDSP-style 8-character display, a great addition for a modern take on this vintage chip. Onboard there is 46 KB of RAM and with the addition of the CompactFlash for storage the LT6502 runs EhBASIC which we’ve seen before in some other great projects.

The case is mainly 3D-printed safely enclosing the custom PCBs for both the keyboard and motherboard, and providing a satisfying glow with the built-in LEDs within. All of the files are up on the project’s site so be sure to swing by and check out both this and the desktop PC/104 predecessor to it. Great job [TechPaula], looking forward to seeing the future installments on the LT6502 such as implementing the included internal expansion slot.

Bruteforcing Accidental Antenna Designs

February 17, 2026 by 13 Comments

Antenna design is often referred to as a black art or witchcraft, even by those experienced in the space. To that end, [Janne] wondered—could years of honed skill be replaced by bruteforcing the problem with the aid of some GPUs? Iterative experiments ensued.

[Janne]’s experience in antenna design was virtually non-existent prior to starting, having a VNA on hand but no other knowledge of the craft. Formerly, this was worked around by simply copying vendor reference designs when putting antennas on PCBs. However, knowing that sometimes a need for something specific arises, they wanted a tool that could help in these regards.

The root of the project came from a research paper using an FDTD tool running on GPUs to inversely design photonic nanostructures. Since light is just another form of radio frequency energy, [Janne] realized this could be tweaked into service as an RF antenna design tool. The core simulation engine of the FDTD tool, along with its gradient solver, were hammered into working as an antenna simulator, with [Janne] using LLMs to also tack on a validation system using openEMS, an open-source electromagnetic field solver. The aim was to ensure the results had some validity to real-world physics, particularly important given [Janne] left most of the coding up to large language models. A reward function development system was then implemented to create antenna designs, rank them on fitness, and then iterate further.

The designs produced by this arcane system are… a little odd, and perhaps not what a human might have created. They also didn’t particularly impress in the performance stakes when [Janne] produced a few on real PCBs. However, they do more-or-less line up with their predicted modelled performance, which was promising. Code is on Github if you want to dive into experimenting yourself. Experienced hands may like to explore the nitty gritty details to see if the LLMs got the basics right.

We’ve featured similar “evolutionary” techniques before, including one project that aimed to develop a radio. If you’ve found ways to creatively generate functional hardware from boatloads of mathematics, be sure to let us know on the tipsline!

Custom VR Headset Uses Unconventional Displays

February 17, 2026 by 13 Comments

Cathode ray tubes (CRTs) are a fascinating display technology that has been largely abandoned outside of retro gaming and a few other niche uses. They use magnets to steer a beam of electrons rapidly across a screen, and while a marvel of engineering for their time, their expense, complexity, and weight all led to them being largely replaced by other displays like LCDs and LEDs. They were also difficult to miniaturize, but there were a few companies who tried. [dooglehead] located a few of the smallest CRT displays he could find and got to work putting them in the most unlikely of situations: a virtual reality headset.

The two displays for his headset come from Sony Watchmans, compact over-the-air black-and-white handheld televisions from the late 1900s. [dooglehead] had to create a method for sending video to these units which originally had no input connections, and then also used an FPGA to split a video signal into two parts, with one for each display. The two displays are placed side by side and attached to a Google Cardboard headset, with an off-the-shelf location tracker attached at the top. An IMU tracks head rotation while this location tracker tracks the motion of the unit through 3D space.

With everything assembled and ready to go, the CRT VR headset only weighs in a few grams heavier than [dooglehead]’s modern HTC headset, although it’s lacking a case (which is sorely needed to cover up the exposed high voltage of the CRTs). He reports surprisingly good performance, with notable interlacing and focus issues. He doesn’t plan to use it to replace any of his modern VR displays anytime soon, but it was an interesting project nonetheless. There are some rumors that CRTs are experiencing a bit of a revival, so we’d advise anyone looking to toss out an old CRT to at least put it on an online market place before sending it to a landfill.

Continue reading “Custom VR Headset Uses Unconventional Displays” →

3D Printed Jack Mixes Two Filaments For Great Performance

February 17, 2026 by 9 Comments

If you’re looking to jack up your car and you don’t have anything on hand, your 3D printer might not be the first tool you look towards. With that said, [Alan Reiner] had great success with a simple idea to create a surprisingly capable scissor jack with a multi-material print.

The design will look familiar if you’ve ever pulled the standard jack out of the back of your car. However, this one isn’t made fully out of steel. It relies on an M6 bolt and a rivet nut, but everything else is pure plastic. In this scissor jack design, rigid PETG arms are held in a scissor jack shape with a flexible TPU outer layer. Combined with the screw mechanism, it’s capable of delivering up to 400 pounds of force without failing. It’s an impressive figure for something made out of 80 grams of plastic. The idea came about because of [Alan’s] recent build of a RatRig VCore4 printer, which has independent dual extruders. This allowed the creation of single prints with both rigid and flexible filaments included.

[Alan] did test the jack by lifting up his vehicle, which it kind of achieved. The biggest problem was the short stroke length, which meant it could only raise the back of the car by a couple inches. Printing a larger version could make it a lot more practical for actual use… if you’re willing to trust a 3D-printed device in such use.

Files are on Printables if you wish to make your own. It’s worth paying attention to the warning upfront that [Alan] provides—”THIS CAN CREATE A LOT OF FORCE (400+ lbs!), WHICH MEANS IT CAN STORE A LOT OF ENERGY THAT MIGHT BE RELEASED SUDDENLY.  Please be cautious using 3d-printed objects for high loads and wear appropriate safety equipment!”

Funnily enough, we’ve featured 3D printed jacks before, all the way back in 2015! Video after the break.

Continue reading “3D Printed Jack Mixes Two Filaments For Great Performance” →

LEGO Orrery Gets A Real-Time Drive Upgrade

February 17, 2026 by 3 Comments

An orrery is a beautiful type of mechanical contrivance, built to demonstrate the motion of heavenly objects. LEGO happens to offer just such a device, built using its Technic line of blocks, shafts, and gears. Only, it has a serious limitation—it has to be cranked manually to make it spin the Earth around the sun. [Görkem] set out to fix this glaring oversight with some good old-fashioned hardware.

The setup removes just five LEGO pieces from the original design, eliminating the hand crank from the mechanism. In its place, [Görkem] installed a NEMA 17 stepper motor, paired with a custom PCB mounted on the back. That carries an ESP32 microcontroller and a TMC2208 stepper motor driver set up for silent drive. Rigged up like so, the orrery can simulate the motion of the Earth and Moon around the Sun in real time. There’s also a knob to track back and forth in time, and a button to reset the system to the correct real-time position.

The final build looks great, combining the LEGO Technic parts with some chunky electronics and 7-segment displays that make it a wonderful techy desk decoration. Down the line, [Görkem] hopes to offer a plug-and-play kit to others who wish to duly animate their own LEGO orrery sets (set #42179).

We love a good LEGO build around these parts. We’ve featured everything from parts sorters to functional typewriters in the past.

Continue reading “LEGO Orrery Gets A Real-Time Drive Upgrade” →

An animated set of circles and lines are drawn on a black screen. Meanwhile, in a smaller window in the lower right corner, the boot screen of a Game Boy is displayed.

Running Pokémon With A Compass And Straightedge

February 17, 2026 by 5 Comments

The ancient question of whether or not it’s possible to construct a circle with the same area as a given square using only a drawing compass and straightedge was finally answered in 1882, where it was proved that pi is a transcendental number, meaning it cannot be accurately represented in a compass-and-straightedge system. This inability to accurately represent pi is just one of the ways in which these systems resemble a computer, a similarity that [0x0mer] explored in CasNum.

The core of the program represents operations with a drawing compass and unmarked straightedge. There are only a few operations that can be used for calculation: constructing a line through two points, constructing a circle centered at one point and intersecting another point, and constructing the intersection(s) of two lines, a line and a circle, or two circles. An optional viewer visualizes these operations. Another class builds on top of this basic environment to perform arithmetic and logical operations, representing numbers as points in the Cartesian plane. To add two numbers, for example, it constructs the midpoint between them, then doubles the distance from the origin.

There are some examples available, including the RSA algorithm. [0x0mer] also altered a Game Boy emulator to implement the ALU instructions using compass and straightedge operations. In testing, it took about fifteen minutes to boot, and runs at a “totally almost playable” speed, near one FPS. This is after extensive caching has been applied to minimize computation time; the performance here is impressive, but in a more qualitative than quantitative sense.

Being virtual, this system is discrete, but a physical compass and straightedge form a simple analog computer capable of dealing with continuous values.

The Complicated Legacy Of Mind Controlled Toys

February 17, 2026 by 13 Comments

Imagine a line of affordable toys controlled by the player’s brainwaves. By interpreting biosignals picked up by the dry electroencephalogram (EEG) electrodes in an included headset, the game could infer the wearer’s level of concentration, through which it would be possible to move physical objects or interact with virtual characters. You might naturally assume such devices would be on the cutting-edge of modern technology, perhaps even a spin-off from one of the startups currently investigating brain-computer interfaces (BCIs).

But the toys in question weren’t the talk of 2025’s Consumer Electronics Show, nor 2024, or even 2020. In actual fact, the earliest model is now nearly as old as the original iPhone. Such is the fascinating story of a line of high-tech toys based on the neural sensor technology developed by a company called Neurosky, the first of which was released all the way back in 2009.

Yet despite considerable interest leading up to their release — fueled at least in part by the fact that one of the models featured Star Wars branding and gave players the illusion of Force powers — the devices failed to make any lasting impact, and have today largely fallen into obscurity. The last toy based on Neurosky’s technology was released in 2015, and disappeared from the market only a few years later.

I had all but forgotten about them myself, until I recently came across a complete Mattel Mindflex at a thrift store for $8.99. It seemed a perfect opportunity to not only examine the nearly 20 year old toy, but to take a look at the origins of the product, and find out what ultimately became of Neurosky’s EEG technology. Was the concept simply ahead of its time? In an era when most people still had flip phones, perhaps consumers simply weren’t ready for this type of BCI. Or was the real problem that the technology simply didn’t work as advertised?

Continue reading “The Complicated Legacy Of Mind Controlled Toys” →