Candle Powered Lantern Isn’t As Silly As You Think

July 6, 2024 by Adam Fabio 30 Comments

[Gilles Messier] at the Our Own Devices YouTube channel recently took a look at an interesting device — an electric lantern powered by a candle. At first glance, this sounds completely absurd. Why use a candle to power LEDs when you can use the light from the candle itself? This gadget has a trick up its sleeve, though. It lets candle light out and uses the heat from the candle flame to generate power for the LEDs.

The small Peltier “solid-state heat pump” module in the lantern acts as a thermoelectric generator, converting heat from the candle into electricity for the LEDs. The genius of the device is how it handles the candle “exhaust”. A bimetallic disk in the chimney of the lantern closes when the air inside the device is hot. The Peltier device converts the heat differential to electricity, causing the air inside the lantern to cool. Meanwhile, the candle is beginning to starve for oxygen. Once the air cools down a bit, the disk bends, allowing stale smoke out, and fresh air in, allowing the candle to burn brightly again. Then the cycle repeats.

[Gilles] does a deep dive into the efficiency of the lantern, which is worth the price of admission alone. These lanterns are pretty expensive — but Peltier modules are well-known by hackers. We’re sure it won’t be too hard to knock together a cheap version at home.

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Target Lifting Mechanism Goes Wireless

February 11, 2024 by Adam Fabio 6 Comments

“WARNING: DO NOT Hammer on this mechanism” sounds like the start of a side quest. A quest is exactly what [CelGenStudios] started when he came upon a strange box with this message.

The military identification tag was printed “Target Holding Mechanism, M31A1”, along with some other information. It also informed the reader that the device weighed 70lbs (31.75kg). Something carrying that much mass just had to be good.

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[Usagi] Whips A Chain Printer Into Shape

February 8, 2024 by Adam Fabio 7 Comments

What does it take to get a 47-year-old printer working? [Usagi Electric] shows us it’s not too hard, even if you don’t exactly know what you’re doing. When we last left this project, he’d tested and verified his power supply was working. This week, after a bit of cleaning, it was time to dig into the mechanics.

If you haven’t seen a chain printer in action before, definitely check one out. They’re big, loud, and sound a bit like a turbine when they spool up. The type chains on these printers never stops moving. This means the printer has to know exactly where a particular letter is before launching one of 66 hammers at it. If the timing is off, parts will fly. To the average computer user, they’re quite intimidating.

Thankfully [Usagi’s] printer was in pretty good shape. When he flipped the big power switch, there was plenty of strange noises, culminating in the test pattern of dollar signs. Probably an early reminder to customers that they needed to order more print supplies.

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Beating Bitlocker In 43 Seconds

February 6, 2024 by Adam Fabio 69 Comments

How long does it take to steal your Bitlocker keys? Try 43 seconds, using less than $10 in hardware. Encrypting your hard drive is good security. If you’re running Windows, the most popular system is BitLocker, which has come with Windows since Vista. We’ve known for some time that Bitlocker could be defeated with direct access to the hardware. Microsoft claims that the process requires an attacker with skill and lengthy access to the hardware. [Stacksmashing] wanted to define lengthy, so he gave it a try. The result is a shockingly fast attack.

Anyone who uses Windows has probably run into Bitlocker. Your hard drive is encrypted, and Bitlocker runs silently in the background, decrypting data on demand. The problem is key storage. In a simplified sense, encryption keys are stored in the Trusted Platform Module (TPM). When your computer boots, it reads the key from the TPM over the LPC (low pin count) bus, which is one of the last remnants of the original ISA bus.

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Crusty: The Story Of The Mac SE That Could

January 23, 2024 by Adam Fabio 25 Comments

Retrocomputing often involves careful restorations, rare components, and white gloves. This story involves none of those. This is the story of two people who sought to answer one of the greatest questions in the universe: What does it take to kill a Mac SE?

The star of the show here is Crusty, a Mac SE that was found on the loading dock of a scrap company. It sat out in the weather for at least 6 months, complete with the original leaking lithium battery.

Enter [RadRacer203], who is friends with the owner of this particular scrap company. [RadRacer203] and picked up Crusty, along with a few other classic Macs. He brought these machines to VCF East 2021, where our other hero comes in. [CJ] is something of a magician with CRTs and analog electronics. Trained under [Sark] himself, [CJ] has mastered the 5-finger exploding capacitor technique.

The battery had eaten through the mainboard and even into the chassis. But after a thorough cleaning, the damn thing booted up. Crusty was born.

This Mac was a survivor. Much like Top Gear and their plucky Toyota Hilux, [RadRacer203] and [CJ] devised a plan to put Crusty to the test.

Click through the break for more!

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Bringing A Chain Printer Back To Life: The Power Supply

January 8, 2024 by Adam Fabio 25 Comments

[Usagi Electric] has his Centurion minicomputer (and a few others) running like a top. One feature that’s missing, though, is the ability to produce a hard copy. Now, a serious machine like the Centurion demands a serious printer. The answer to that is an ODEC-manufactured printer dressed in proper Centurion blue. This is no ordinary desktop printer, though. It’s a roughly 175lb (80 Kg) beast capable of printing 100 lines per minute. Each line is 132 characters wide, printed on the tractor-feed green bar paper we all associate with old computer systems.

This sort of printer was commonly known as a chain printer, as the letters are on a chain that rides over a series of 66 hammers. Logic on this printer is 74 series logic chips – no custom silicon or LSI (Large Scale Integration) parts on this 47-year-old monster.

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Mini Meters Monitor Microprocessor Maximization

December 4, 2023 by Adam Fabio 11 Comments

[Lex] over at Computing: The Details loves to make fun projects. Recently, they have created a hardware CPU monitor that displays how PCs are parallelizing compile tasks at a glance. The monitor is built from 14 analog meters, along with some WS2812 RGB LEDs.

Each meter represents a core on [Lex]’s CPU, while the final two meters show memory and swap usage. The meters themselves are low-cost 5 mA devices. Of course, the original milliamps legends wouldn’t do much good, so [Lex] designed and printed graduations that glue over the top. The RGB LED strip is positioned so two LEDs fit under each meter. The LEDs allow a splash of color to draw attention to the current state of the machine. The whole bank going red would sure get our attention!

The system is controlled by an Arduino Mega, with the meters driven using the PWM pins. The only extra part is a 1 kΩ resistor. The Arduino wrangles the LEDs as well. Sadly [Lex] did not include the software. They did describe it though. Basically they are using a Rust program to call systemstat, obtaining the current CPU utilization data in Linux. A bit of math converts this into pointer values and LED colors. The data is then sent via USB-serial to the Arduino Mega. The software savvy will say it’s pretty easy to replicate, but the hardware-only hackers among us might need a bit of help.

This isn’t the first custom meter we’ve seen on Hackaday. Your author’s first project covered by Hackaday was for a meter created using an automotive gauge stepper motor. I didn’t include source code either – but only because [Guy Carpenter]’s Switec X25 library had me covered.

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