Author: Al Williams

4370 Articles

The History Of Tandem Computers

January 26, 2026 by 3 Comments

If you are interested in historical big computers, you probably think of IBM, with maybe a little thought of Sperry Rand or, if you go smaller, HP, DEC, and companies like Data General. But you may not have heard of Tandem Computers unless you have dealt with systems where downtime was unacceptable. Printing bills or payroll checks can afford some downtime while you reboot or replace a bad board. But if your computer services ATM machines, cash registers, or a factory, that’s another type of operation altogether. That was where Tandem computers made their mark, and [Asianometry] recounts their history in a recent video that you can watch below.

When IBM was king, your best bet for having a computer running nonstop was to have more than one computer. But that’s pricey. Computers might have some redundancy, but it is difficult to avoid single points of failure. For example, if you have two computers with a single network connection and a single disk drive. Then failures in the network connection or the disk drive will take the system down.

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Ancient Egyptian Flatness

January 24, 2026 by 37 Comments

Making a truly flat surface is a modern engineering feat, and not a small one. Even making something straight without reference tools that are already straight is a challenge. However, the ancient Egyptians apparently made very straight, very flat stone work. How did they do it? Probably not alien-supplied CNC machines. [IntoTheMap] explains why it is important and how they may have done it in a recent video you can see below.

The first step is to define flatness, and modern mechanical engineers have taken care of that. If you use 3D printers, you know how hard it is to even get your bed and nozzle “flat” with respect to each other. You’ll almost always have at least a 100 micron variation in the bed distances. The video shows how different levels of flatness require different measurement techniques.

The Great Pyramid’s casing stones have joints measuring 0.5 mm, which is incredible to achieve on such large stones with no modern tools. A stone box in the Pyramid of Seostris II is especially well done and extremely flat, although we can make things flatter today.

The main problem with creating a flat surface is that to do a good job, you need some flat things to start with. However, there is a method from the 19th century that uses three plates and multiple lapping steps to create three very flat plates. In modern times, we use a blue material to indicate raised areas, much as a dentist makes you chomp on a piece of paper to place a crown. There are traces of red ochre on Egyptian stonework that probably served the same purpose.

Lapping large pieces is still a challenge, but moving giant stones at scale appears to have been a solved problem for the Egyptians. Was this the method they used? We don’t know, of course. But it certainly makes sense.

It would be a long time before modern people could make things as flat. While we can do even better now, we also have better measuring tools.

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Environmental Monitoring On The Cheap

January 24, 2026 by 5 Comments

If there is one thing we took from [azwankhairul345’s] environmental monitor project, it is this: sensors and computing power for such a project are a solved problem. What’s left is how to package it. The solution, in this case, was using recycled plastic containers, and it looks surprisingly effective.

A Raspberry Pi Pico W has the processing capability and connectivity for a project like this. A large power bank battery provides the power. Off-the-shelf sensors for magnetic field (to measure anemometer spins), air quality, temperature, and humidity are easy to acquire. The plastic tub that protects everything also has PVC pipe and plastic covers for the sensors. Those covers look suspiciously like the tops of drink bottles.

We noted that the battery bank inside the instrument doesn’t have a provision for recharging. That means the device will go about two days before needing some sort of maintenance. Depending on your needs, this could be workable, or you might have to come up with an alternative power supply.

This probably won’t perform as well as a Hoffman box-style container, and we’ve seen those crop up, too. There are a number of ways of sealing things against the elements.

Hackaday Podcast Episode 354: Firearms, Sky Driving, And Dumpster Diving

January 23, 2026 by 1 Comment

Hackaday Editors Elliot Williams and Al Williams took a break to talk about their favorite hacks last week. You can drop in to hear about articulated mirrors, triacs, and even continuous 3D-printing modifications.

Flying on an airplane this weekend? Maybe wait until you get back to read about how the air traffic control works. Back home, you can order a pizza on a Wii or run classic Basic games on a calculator.

For the can’t miss articles, the guys talked about very low Earth orbit satellites and talked about readers who dumpster dive.

Check out the links below if you want to follow along, and don’t be shy. Tell us what you think about this episode in the comments!

As always, this episode is available in DRM-free MP3.

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

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Size (and Units) Really Do Matter

January 23, 2026 by 88 Comments

We miss the slide rule. It isn’t so much that we liked getting an inexact answer using a physical moving object. But to successfully use a slide rule, you need to be able to roughly estimate the order of magnitude of your result. The slide rule’s computation of 2.2 divided by 8 is the same as it is for 22/8 or 220/0.08. You have to interpret the answer based on your sense of where the true answer lies. If you’ve ever had some kid at a fast food place enter the wrong numbers into a register and then hand you a ridiculous amount of change, you know what we mean.

Recent press reports highlighted a paper from Nvidia that claimed a data center consuming a gigawatt of power could require half a million tons of copper. If you aren’t an expert on datacenter power distribution and copper, you could take that number at face value. But as [Adam Button] reports, you should probably be suspicious of this number. It is almost certainly a typo. We wouldn’t be surprised if you click on the link and find it fixed, but it caused a big news splash before anyone noticed.

Thought Process

Best estimates of the total copper on the entire planet are about 6.3 billion metric tons. We’ve actually only found a fraction of that and mined even less. Of the 700 million metric tons of copper we actually have in circulation, there is a demand for about 28 million tons a year (some of which is met with recycling, so even less new copper is produced annually).

Simple math tells us that a single data center could, in a year, consume 1.7% of the global copper output. While that could be true, it seems suspicious on its face.

Digging further in, you’ll find the paper mentions 200kg per megawatt. So a gigawatt should be 200,000kg, which is, actually, only 200 metric tons. That’s a far cry from 500,000 tons. We suspect they were rounding up from the 440,000 pounds in 200 metric tons to “up to a half a million pounds,” and then flipped pounds to tons.

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Embedded TPM: Watch Out!

January 23, 2026 by 62 Comments

Today’s PCs are locked up with Trusted Platform Module (TPM) devices so much so that modern Windows versions insist on having a recent TPM to even install. These have become so prevalent that even larger embedded boards now have TPM and, of course, if you are repurposing consumer hardware, you’ll have to deal with it, too. [Sigma Star] has just the primer for you. It explains what TPM does, how it applies to embedded devices, and where the pitfalls are.

The TPM is sometimes a chip or sometimes secure firmware that is difficult to tamper with. They provide secret storage and can store boot signatures to detect if something has changed how a computer starts up. The TPM can also “sign off” that the system configuration is the same to a remote entity. This allows, for example, a network to prevent a hacked or rogue computer from communicating with other computers.

Embedded systems, usually, aren’t like PCs. A weather station at a remote location may have strangers poking at it without anyone noticing. Also, that remote computer might be expected to be working for many more years than a typical laptop or desktop computer.

This leads to a variety of security concerns that TPM 2.0 attempts to mitigate. For example, it is unreasonable to think a typical attacker might connect a logic analyzer to your PC, but for an embedded system, it is easier to imagine. There is a session-based encryption to protect against someone simply snooping traffic off the communication bus. According to the post, not all implementations use this encryption, however.

Motherboard has a slot for TPM, but no board? We’ve seen people build their own TPM boards.

Title image by [Raimond Spekking] CC BY-SA-4.0

A 1970s Electronic Game

January 22, 2026 by 2 Comments

What happens when a traditional board game company decides to break into electronic gaming? Well, if it were a UK gaming company in 1978, the result would be a Waddingtons 2001 The Game Machine that you can see in the video from [Re:Enthused] below.

The “deluxe console model” had four complete games: a shooting gallery, blackjack, Code Hunter, and Grand Prix. But when you were done having fun, no worries. The machine was also a basic calculator with a very strange keyboard. We couldn’t find an original retail price on these, but we’ve read it probably sold for £20 to £40, which, in 1978, was more than it sounds like today.

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