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MNT’s tiny PC has a mechanical keyboard and old-school trackball

MNT’s Reform Pocket is a 7-inch computer with open-source software and hardware.

Open-source PC hardware is coming to a new frontier: your pocket.

MNT, a small German company “driven by the idea of a digital future that is open-source, accessible and modular,” will soon release the MNT Pocket Reform, a pint-size alternative to the full-size Reform laptop introduced in 2019. The pocketable spin-off combines a 7-inch, 1080p display with a miniature physical keyboard and fully modular internals packing your choice of several Arm-based processors.

The result is a bizarre PC like nothing else sold today. It’s not for everyone—but hardware enthusiasts and hard-core DIY tinkerers will find a lot to like.

My initial fear that MNT’s diminutive PC might feel fragile was quickly dispelled. Though small, the Pocket Reform has a hefty, machined aluminum chassis tied together by rigid metal hinges. Most surfaces, including the exterior display lid, are user-replaceable plastic panels. The device’s weight remains to be announced, but it feels dense, and its materials have no hint of flex. Its heft and size are arguably downsides, though, as the Pocket Reform is too large to be truly pocketable in pants that go with business attire (though I hear cargo pants are back in style).

Opening the Pocket Reform reveals a pleasant surprise: a mechanical keyboard with Kailh Choc White low-profile switches and custom keycaps. The result is bafflingly good. It easily tops the laptops I’ve tested in recent years (I’ve tried hundreds) and bests many full-size mechanical keyboards. It’s crisp and clicky, yet not loud enough to distract the person seated next to you on a flight. The keyboard is LED-backlit, and the lighting’s color can be customized—an eye-catching addition I didn’t expect.

The Pocket Reform’s LED backlit keyboard includes color customization.Matthew S. Smith

The Pocket Reform’s keyboard layout is unusual, as keys are arranged in an evenly distributed grid. The twin space-bar keys double as mouse inputs. Holding the left-most space-bar key allows scrolling when combined with the Pocket Reform’s smooth trackball. My typing speed slowed to a crawl as I struggled to understand the layout’s quirks, but I think the odd layout is smart move. It retains full keyboard and mouse functionality and allows for larger keycaps. Just expect to deal with a learning curve.

MNT’s first batch of Pocket Reforms will be powered by NXP’s iMX8MPlus, a quad-core Arm processor with Cortex A53 cores clocked at up to 1.8 gigahertz. The system also has 8 gigabytes of RAM, supports both eMMC and NVMe storage, and comes with onboard Wi-Fi and Bluetooth. Additional modules will arrive later. An optional cellular modem is planned, too.

It’s not a powerhouse, to be sure, but MNT expects performance roughly on par with the Raspberry Pi 4. The Web browsing experience felt smooth while scrolling through Web pages and flipping through multiple tabs, even over a cellular data connection provided by an iPhone. However, the device stumbled when attempting high-resolution streaming video in Firefox; I’m told Chrome performs better.

Perhaps what I’ve described sounds exciting—but what if doesn’t? Don’t dismiss the Pocket Reform just yet. It’s not just a device, but a canvas upon which open-source ideals have been applied to put users in control.

“For us that is a combination of open hardware and open software along with community contributions to create something that we’re calling open-computing autonomy,” an international PR representative said while demoing the device. MNT wants to encourage an open-source “feedback loop” that lets users take the lead on customizing and improving their Pocket Reform.

If you’re curious what that looks like in practice, just look toward the Reform, MNT’s full-size laptop. Inspiration from owners has led to numerous improvements, such as a new ball-bearing design for the trackball. Other users have swapped in alternative keyboard layouts, such as an ergonomic split-key keyboard—something you won’t find on any other laptop sold today. MNT provides extensive technical details including renderings of 3D models of device components plus schematics of the motherboard. Owners can also swap in different hardware modules to fit their needs.

A rigid aluminum chassis gives the Pocket Reform plenty of rigidity. Matthew S. Smith

“Probably the most complex, nerdy option, is the FPGA [field-programmable gate array] based board, which is now shipping. It’s really expensive, because they’re made by hand. It’s like €1,600,” says MNT’s representative.

The hand-crafted board can emulate other devices at the hardware level, providing accuracy and performance not possible through software emulation. Crafty users might use it to transform the Pocket Reform into a pocketable RadioShack TRS-80 or Amiga 1200 (FPGA-based devices like the Analog Pocket and MiSTer already do this, though the community around them is most focused on emulating game systems).

Those seeking the ultimate in open source will appreciate a new module with an NXP Layerscape LS1028A processor and a rare open-source memory controller. The embedded DisplayPort controller is the only closed firmware remaining, though MNT says users could bypass it if desired. Owners of a Pocket Reform (or standard Reform) with this module could in theory change or modify anything their technical skills allow.

MNT will offer an optional vegan leather case for the Pocket Reform.Matthew S. Smith

Clearly, the Pocket Reform isn’t an alluring alternative to an iPad, or even a Windows laptop. But that’s not the point. It’s a clever, customizable device built for people who want the ultimate in control over their PC. In that regard, the Pocket Reform has no peer, and I suspect its unique form factor will give it lasting appeal.

MNT is finalizing the Pocket Reform’s design, but preorders are expected to hit Crowdsupply within the next few weeks. Expect a starting price of roughly US $900.

Matthew S. Smith is a freelance consumer-tech journalist. An avid gamer, he is a former staff editor at Digital Trends and is particularly fond of wearables, e-bikes, all things smartphone, and CES, which he has attended every year since 2009.

Open Circuits showcases the surprising complexity of passive components

Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.” From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor. High-Stability Film Resistor All photos by Eric Schlaepfer & Windell H. Oskay This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film. Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy. 15-Turn Trimmer Potentiometer It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety. The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers. Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film. Ceramic Disc Capacitor Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator. A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage. Film Capacitor Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene. The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value. Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film. Dipped Tantalum Capacitor At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid. Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use. The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet. Axial Inductor Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics. Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor. This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value. Power Supply Transformer This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet. The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape. The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current. All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.”

From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor.

All photos by Eric Schlaepfer & Windell H. Oskay

This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film.

Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy.

It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety.

The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers.

Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film.

Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator.

A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage.

Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene.

The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value.

Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film.

At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid.

Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use.

The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet.

Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics.

Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor.

This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value.

This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet.

The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape.

The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current.

All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

This article appears in the February 2023 print issue.