Wire Photo Fax Teardown

August 24, 2025 by 14 Comments

Fax machines had a moment in the sun, but they are actually much older than you might expect. Before the consumer-grade fax machines arrived, there was a thriving market for “wire photos” used by, for example, news organizations and the weather service. In the United States, the WEFax from Western Electric was fairly common and shows up on the surplus market. [Thomas] has an English unit, a Muirhead K-570B, that is very clearly not a consumer-oriented machine. His unit dates back to 1983, but it reminds us of many older designs. Check out his teardown in the video below.

The phone line connection on this device is a pair of banana jacks! There are even jacks for an external meter. Inside, the device is about what you’d expect for a 1983 build. PCBs with bare tinned conductors and lots of through-hole parts.

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A golden robotic hand is shown in the main picture performing the sign for the letter "g": pointing to the left, with all fingers except for the index finger curled. In the top left of the image, a human hand is shown imitating this position.

Ambidextrous Robot Hand Speaks In Signs

August 24, 2025 by 5 Comments

As difficult as it is for a human to learn ambidexterity, it’s quite easy to program into a humanoid robot. After all, a robot doesn’t need to overcome years of muscle memory. Giving a one-handed robot ambidexterity, however, takes some more creativity. [Kelvin Gonzales Amador] managed to do this with his ambidextrous robot hand, capable of signing in either left- or right-handed American Sign Language (ASL).

The essential ingredient is a separate servo motor for each joint in the hand, which allows each joint to bend equally well backward and forward. Nothing physically marks one side as the palm or the back of the hand. To change between left and right-handedness, a servo in the wrist simply turns the hand 180 degrees, the fingers flex in the other direction, and the transformation is complete. [Kelvin] demonstrates this in the video below by having the hand sign out the full ASL alphabet in both the right and left-handed configurations.

The tradeoff of a fully direct drive is that this takes 23 servo motors in the hand itself, plus a much larger servo for the wrist joint. Twenty small servo motors articulate the fingers, and three larger servos control joints within the hand. An Arduino Mega controls the hand with the aid of two PCA9685 PWM drivers. The physical hand itself is made out of 3D-printed PLA and nylon, painted gold for a more striking appearance.

This isn’t the first language-signing robot hand we’ve seen, though it does forgo the second hand. To make this perhaps one of the least efficient machine-to-machine communication protocols, you could also equip it with a sign language translation glove.

Pong Cloned By Neural Network

August 24, 2025 by 9 Comments

Although not the first video game ever produced, Pong was the first to achieve commercial success and has had a tremendous influence on our culture as a whole. In Pong’s time, its popularity ushered in the arcade era that would last for more than two decades. Today, it retains a similar popularity partially for approachability: gameplay is relatively simple, has hardwired logic, and provides insights about the state of computer science at the time. For these reasons, [Nick Bild] has decided to recreate this arcade classic, but not in a traditional way. He’s trained a neural network to become the game instead.

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The 32 Bit 6502 You Never Had

August 24, 2025 by 43 Comments

In the beginning was the MOS6502, an 8-bit microprocessor that found its way into many famous machines. Some of you will know that a CMOS 6502 was created by the Western Design Center, and in turn, WDC produced the 65C816, a 16-bit version that was used in the Apple IIgs as well as the Super Nintendo. It was news to us that they had a 32-bit version in their sights, but after producing a datasheet, they never brought it to market. Last October, [Mike Kohn] produced a Verilog version of this W65C832 processor, so it can be experienced via an FPGA.

The description dives into the differences between the 32, 16, and 8-bit variants of the 6502, and we can see some of the same hurdles that must have faced designers of other chips in that era as they moved their architectures with the times while maintaining backwards compatibility. From our (admittedly basic) understanding it appears to retain that 6502 simplicity in the way that Intel architectures did not, so it’s tempting to imagine what future might have happened had this chip made it to market. We’re guessing that you would still be reading through an Intel or ARM, but perhaps we might have seen a different path taken by 1990s game consoles.

If you’d like to dive deeper into 6502 history, the chip recently turned 50.

Thanks [Liam Proven] for the tip.

The Oscilloscope From 1943

August 23, 2025 by 5 Comments

[Thomas] comes up with some unusual gear. In his latest teardown and repair video, he has a vintage 1943 Danish oscilloscope,  a Radiometer OSG32 on the bench. It isn’t lightweight, and it certainly looks its age with a vintage cracked finish on the case. You can check out the tubes and high-voltage circuitry in the video below.

If you’ve only seen the inside of a modern scope, you’ll want to check this out with giant condensers (capacitors) and a slew of tubes. We love seeing the workmanship on these old chassis.

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Dealing With The 1970s EPROM Chaos In 2025

August 23, 2025 by 15 Comments

It could be argued that erasable programmable ROMs (EPROMs) with their quaint UV-transparent windows are firmly obsolete today in an era of various flavors of EEPROMs. Yet many of these EPROMs are still around, and people want to program them. Unfortunately, the earliest EPROMs were made during a time when JEDEC standardization hadn’t taken root yet, leading to unique pinouts, programming voltages, and programming sequences, as [Anders Nielsen] explains in a recent video.

[Anders]’s Relatively Universal-ROM-Programmer project recently gained the ability to program even the oldest types of EPROMs, something which required modifying the hardware design to accommodate EPROMs like Ti’s TMS2716 and the similar-but-completely-different TMS2516. Although not the hardest thing to support – requiring just a diode and resistor added to the BOM along with a firmware update – it’s just one of those pre-standardization traps.

As [Anders] put it, it’s sometimes good to be unencumbered by the burden of future knowledge. Who would have willingly subjected themselves to the chaos of incompatible pinouts, voltages, etc., if they had known beforehand that in a few years EEPROMs and JEDEC standardization would make life so much easier? Maybe that’s why messing with retro hardware like this is fun, as afterwards you can go back to the future.

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Picking An Old Operating System

August 23, 2025 by 50 Comments

We usually at least recognize old computer hardware and software names. But [Asianometry] taught us a new one: Pick OS. This 1960s-era system was sort of a database and sort of an operating system for big iron used by the Army. The request was for an English-like query language, and TRW assigned two guys, Don Nelson and Dick Pick, to the job.

The planned query language would allow for things like “list the title, author, and abstract of every transportation system reference with the principal city ‘Los Angeles’.” This was GIM or generalized information management, and, in a forward-looking choice, it ran in a virtual machine.

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