Author: Al Williams

4378 Articles

Tearing Down A Vintage Word Processor

March 7, 2025 by 3 Comments

There was a time when the line between typewriters and word processing software was a bit fuzzy. [Poking Technology] found a Xerox 6040 which can’t decide what it is. It looks like a typewriter but has a monitor and a floppy drive, along with some extra buttons. You can watch him tear it down in the video below.

The old device uses a daisywheel type element, which, back then, was state of the art. A wheel had many spokes with letters and the printer would spin the wheel and then strike the plastic spoke.

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Repairing A 1955 Classic Radio

March 6, 2025 by 8 Comments

We used to say that fixing something was easier than bringing up a design for the first time. After all, the thing you are fixing, presumably, worked at one time or another. These days, that’s not always true as fixing modern gear can be quite a challenge. Watching [Ken’s] repair of an old 1955 Silvertone radio reminded us of a simpler time. You can watch the action on the video below.

If you’ve never had the pleasure of working on an AM radio, you should definitely try it. Some people would use an amplifier to find where the signal dies out. Others will inject a signal into the radio to find where it stops. A good strategy is to start at the volume control and decide if it is before or after that. Then split the apparently bad section roughly in half and test that portion—sort of a hardware binary search. Of course, your first step should probably be to verify power, but after that, the hunt is on.

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Combined Crypto, Anglo-American Style

March 6, 2025 by 8 Comments

If you think about military crypto machines, you probably think about the infamous Enigma machine. However, as [Christos T.] reminds us, there were many others and, in particular, the production of a “combined cipher” machine for the US and the UK to use for a variety of purposes.

The story opens in 1941 when ships from the United States and the United Kingdom were crossing the Atlantic together in convoys. The US wanted to use the M-138A and M-209 machines, but the British were unimpressed. They were interested in the M-134C, but it was too secret to share, so they reached a compromise.

Starting with a British Typex, a US Navy officer developed an attachment with additional rotors and converted the Typex into a CCM or Combined Cipher Machine. Two earlier verisons of the attachment worked with the M-134C. However the CSP 1800 (or CCM Mark III) was essentially the same unit made to attach to the Typex. Development cost about $6 million — a huge sum for the middle of last century.

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Plastic Gear Repair

March 6, 2025 by 33 Comments

We’ve seen several methods of repairing plastic gears. After all, a gear is usually the same all the way around, so it is very tempting to duplicate a good part to replace a damaged part. That’s exactly what [repairman 101] does in the video below. He uses hot glue to form a temporary mold and casts a resin replacement in place with a part of a common staple as a metal reinforcement.

The process starts with using a hobby tool to remove even more of the damaged gear, making a V-shaped slot to accept the repair. The next step is to create a mold. To do that, he takes a piece of plastic and uses hot glue to secure it near a good part of the gear. Then, he fills the area with more hot glue and carefully removes it.

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Ptychography For High Resolution Microscopy

March 5, 2025 by 7 Comments

Nowadays, if you have a microscope, you probably have a camera of some sort attached. [Applied Science] shows how you can add an array of tiny LEDs and some compute power to produce high-resolution images — higher than you can get with the microscope on its own. The idea is to illuminate each LED in the array individually and take a picture. Then, an algorithm constructs a higher-resolution image from the collected images. You can see the results and an explanation in the video below.

You’d think you could use this to enhance a cheap microscope, but the truth is you need a high-quality microscope to start with. In addition, color cameras may not be usable, so you may have to find or create a monochrome camera.

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Speaking Computers From The 1970s

March 5, 2025 by 24 Comments

Talking computers are nothing these days. But in the old days, a computer that could speak was quite the novelty. Many computers from the 1970s and 1980s used an AY-3-8910 chip and [InazumaDenki] has been playing with one of these venerable chips. You can see (and hear) the results in the video below.

The chip uses PCM, and there are different ways to store and play sounds. The video shows how different they are and even looks at the output on the oscilloscope. The chip has three voices and was produced by General Instruments, the company that initially made PIC microcontrollers. It found its way into many classic arcade games, home computers, and games like Intellivision, Vectrex, the MSX, and ZX Spectrum. Soundcards for the TRS-80 Color Computer and the Apple II used these chips. The Atari ST used a variant from Yamaha, the YM2149F.

There’s some code for an ATmega, and the video says it is part one, so we expect to see more videos on this chip soon.

General instruments had other speech chips, and some of them are still around in emulated form. In fact, you can emulate the AY-3-8910 with little more than a Raspberry Pi.

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Inexpensive Powder Coating

March 4, 2025 by 17 Comments

[Pete] had a friend who would powder coat metal parts for him, but when he needed 16 metal parts coated, he decided he needed to develop a way to do it himself. Some research turned up the fluid bed method and he decided to go that route. He 3D printed a holder and you can see how it all turned out in the video below.

A coffee filter holds the powder in place. The powder is “fluidized” by airflow, which, in this case, comes from an aquarium pump. The first few designs didn’t work out well. Eventually, though, he had a successful fluid bed. You preheat the part so the powder will stick and then, as usual, bake the part in an oven to cure the powder. You can expect to spend some time getting everything just right. [Pete] had to divert airflow and adjust the flow rate to get everything to work right.

With conventional powder coating, you usually charge the piece you want to coat, but that’s not necessary here. You could try a few other things as suggested in the video comments: some suggested ditching the coffee filter, while others think agitating the powder would make a difference. Let us know what you find out.

This seems neater than the powder coating guns we’ve seen. Of course, these wheels had a great shape for powder coating, but sometimes it is more challenging.

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