Misc Hacks

4028 Articles

Geothermal Cooling For New York’s Subways

September 29, 2026 by 25 Comments

You might think that if you dug some tunnels down into the ground where you could be out of the sunshine, that you might find them to be relatively cool and comfortable inside. Yet, fill those tunnels with trains and supporting equipment and millions of commuters, and you’ll instead find yourself sweltering in the heat.

New York’s subways are too hot for comfort, and have been for some time. Unfortunately, unlike any old regular building, you can’t just air condition a subway and call it done. Instead, authorities are looking for other solutions to beat the heat on the famous underground transit network.

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Pi Pico Recreates The Heathkit Pocket Packet

September 25, 2026 by 9 Comments

Packet radio is a particularly fun part of the ham radio hobby. Once upon a time, you might have squirted data about the airwaves using something like the Heathkit HK-21 Pocket Packet. Heathkit stopped being a going concern some time ago, but [btech] has now recreated the device with modern hardware.

[btech] has called the project the Pocket Pico, and like the hardware that inspired it, it acts as a terminal node controller for amateur packet radio. It literally runs the same firmware as the real HK-21. It achieves this by using the Raspberry Pi Pico to run a Z80 processor emulator that can run the same code, while also using the microcontroller to do the work of modulating and demodulating Bell 202 audio tones at 1200 baud to avoid the need for a dedicated modem chip.

Thanks to running the same firmware as the HK-21, you can use the Pocket Pico with lots of old packet radio software. It’s fully capable of doing APRS as well as AX.25 Level 2, and has a built in Personal Bulletin Board System for other stations to leave messages.

If you’re looking to get into packet radio, you might just find this project to be useful. Alternatively, you might like taking a look at some other projects we’ve featured in this space, like the capable OpenModem project. Video after the break.

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Death Of The Cheque: Australia Moves On

August 20, 2025 by 109 Comments

Check (or cheques) have long been a standard way for moving money from one bank account to another. They’re essentially little more than a codified document that puts the necessary information in a standard format to ease processing by all parties involved in a given transaction.

The check was once a routine, if tedious, way for the average person to pay for things like bills, rent, or even groceries. As their relevance continues to wane in the face of newer technology, though, the Australian government is making a plan to phase them out for good.

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How Laser Headlights Died In The US

August 18, 2025 by 143 Comments

Automotive headlights started out burning acetylene, before regular electric lightbulbs made them obsolete. In due time, halogen bulbs took over, before the industry began to explore even newer technologies like HID lamps for greater brightness. Laser headlights stood as the next leap forward, promising greater visibility and better light distribution.

Only, the fairytale didn’t last. Just over a decade after laser headlights hit the market, they’re already being abandoned by the manufacturers that brought them to fruition. Laser headlights would end up fighting with one hand behind their back, and ultimately became irrelevant before they ever became the norm.

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The Rise And The Fall Of The Mail Chute

June 25, 2025 by 18 Comments

As the Industrial Age took the world by storm, city centers became burgeoning hubs of commerce and activity. New offices and apartments were built higher and higher as density increased and skylines grew ever upwards. One could live and work at height, but this created a simple inconvenience—if you wanted to send any mail, you had to go all the way down to ground level.

In true American fashion, this minor inconvenience would not be allowed to stand. A simple invention would solve the problem, only to later fall out of vogue as technology and safety standards moved on. Today, we explore the rise and fall of the humble mail chute.

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A map of the United States showing a series of interconnected lines in white, red, orange, yellow, and green to denote fiber optic and electrical transmission lines. Dots of white, orange, and yellow denote the location of the data centers relative to nearby metropolitan centers.

NREL Maps Out US Data Infrastructure

June 24, 2025 by 14 Comments

Spending time as wee hackers perusing the family atlas taught us an appreciation for a good map, and [Billy Roberts], a cartographer at NREL, has served up a doozy with a map of the data center infrastructure in the United States. [via LinkedIn]

Fiber optic lines, electrical transmission capacity, and the data centers themselves are all here. Each data center is a dot with its size indicating how power hungry it is and its approximate location relative to nearby metropolitan areas. Color coding of these dots also helps us understand if the data center is already in operation (yellow), under construction (orange), or proposed (white).

Also of interest to renewable energy nerds would be the presence of some high voltage DC transmission lines on the map which may be the future of electrical transmission. As the exact location of fiber optic lines and other data making up the map are either proprietary, sensitive, or both, the map is only available as a static image.

If you’re itching to learn more about maps, how about exploring why they don’t quite match reality, how to bring OpenStreetMap data into Minecraft, or see how the live map in a 1960s airliner worked.

Wood bent into a spiral

Make Magical-Looking Furniture With Kerf Bend Wizard

June 14, 2025 by 26 Comments

The intersection between “woodworkers” and “programmers” is not a densely populated part of the Venn diagram, but [Michael Schiebler] is there with his Kerf Bend Wizard to help us make wood twist and bend like magic.

Kerf bending is a fine technique we have covered before: by cutting away material on the inside face of a piece of wood, you create an area weak enough to allow for bending. The question becomes: how much wood do I remove? And where? That’s where Kerf Bend Wizard comes to the rescue.

More after the break…

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