Inexpensive Repairable Laptops, With Apple Style

Despite a general lack of real-world experience, many teenagers are overly confident in their opinions, often to the point of brashness and arrogance. In the late 90s and early 00s I was no different, firmly entrenched in a clichéd belief that Apple computers weren’t worth the silicon they were etched onto—even though I’d never actually used one. Eventually, thanks to a very good friend in college, a bit of Linux knowledge, and Apple’s switch to Intel processors, I finally abandoned this one irrational belief. Now, I maintain an array of Apple laptops for my own personal use that are not only surprisingly repairable and hacker-friendly but also serve as excellent, inexpensive Linux machines.

Of course, I will have ruffled a few feathers suggesting Apple laptops are repairable and inexpensive. This is certainly not true of their phones or their newer computers, but there was a time before 2016 when Apple built some impressively high quality, robust laptops that use standard parts, have removable batteries, and, thanks to Apple dropping support for these older machines in their latest operating systems, can also be found for sale for next to nothing. In a way that’s similar to buying a luxury car that’s only a few years old and letting someone else eat the bulk of the depreciation, a high quality laptop from this era is only one Linux install away from being a usable and relatively powerful machine at an excellent bargain. Continue reading “Inexpensive Repairable Laptops, With Apple Style”

You Are Already Traveling At The Speed Of Light

Science fiction authors and readers dream of travelling at the speed of light, but Einstein tells us we can’t. You might think that’s an arbitrary rule, but [FloatHeadPhysics] shows a different way to think about it. Based on a book he’s been reading, “Relativity Visualized,” he provides a graphic argument for relativity that you can see in the video below.

The argument starts off by explaining how a three-dimensional object might appear in a two-dimensional world. In this world, everything is climbing in the hidden height dimension at the exact same speed.

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Soviet ZX Spectrum clone on a table

ZX Spectrum, Soviet Style: A 44-IC Clone You Can Build

If you’ve ever fancied building a ZX Spectrum clone without hunting down ancient ULAs or soldering your way through 60+ chips, [Alex J. Lowry] has just dropped an exciting build. He has recreated the Leningrad-1, a Soviet-built Spectrum clone from 1988, with a refreshingly low component count: 44 off-the-shelf ICs, as he wrote us. That’s less than many modern clones like the Superfo Harlequin, yet without resorting to programmable logic. All schematics, Gerbers, and KiCad files are open-source, listed at the bottom of [Alex]’ build log.

The original Leningrad-1 was designed by Sergey Zonov during the late Soviet era, when cloning Western tech was less about piracy and more about survival. Zonov’s design nailed a sweet spot between affordability and usability, with enough compatibility to run 90-95% of Spectrum software. [Alex]’ replica preserves that spirit, with a few 21st-century tweaks for builders: silkscreened component values, clever PCB stacking with nylon standoffs, and a DIY-friendly mechanical keyboard hack using transparent keycaps.

While Revision 0 still has some quirks – no SCART color output yet, occasional flickering borders with AY sound – [Alex] is planning for further improvements. Inspired to build your own? Read [Alex]’ full project log here.

IPV4, IPV6… Hey! What Happened To IPV5?

If you’ve ever been configuring a router or other network device and noticed that you can set up IPv4 and IPv6, you might have wondered what happened to IPv5. Well, thanks to [Navek], you don’t have to wonder anymore. Just watch the video below.

We will warn you of two things. First, the video takes a long time to get around to what IPv5 was. In addition, if you keep reading, there will be spoilers.

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Clock Mechanism Goes Crazy For Arduino

You’ve doubtless seen those ubiquitous clock modules, especially when setting clocks for daylight savings time. You know the ones: a single AA battery, a wheel to set the time, and two or three hands to show the time. They are cheap and work well enough. But [Playful Technology] wanted to control the hands with an Arduino directly and, in the process, he shows us how these modules work.

If you’ve never studied the inside of these clock modules, you may be surprised about how they actually work. A crystal oscillator pulses a relatively large electromagnet. A small plastic gear has a magnetic ring and sits near the electromagnet.

Each time the polarity of the electromagnet flips, the ring turns 180 degrees to face the opposite magnetic pole to the electromagnet. This turns the attached gear which is meshed with other gears to divide the rotation rate down to once per 24 hours, once per hour, and once per minute. Pretty clever.

That makes it easy to control the hands. You simply detach the electromagnet from the rest of the circuit and control it yourself. The module he used had a mechanical limitation that prevents the hands from moving well at more than about 100 times normal speed.

We wondered how he made the hands reverse and, apparently, there is a way to get the drive gear to move in reverse, but it isn’t always reliable. Of course, you could also replace the drive mechanism with something like an RC servo or other motor and it sounds like he has done this and plans to show it off in another video.

We’ve seen the opposite trick before, too. If you really want an easy-to-control analog clock, try this one Continue reading “Clock Mechanism Goes Crazy For Arduino”

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Hackaday Links: March 9, 2025

It’s been a busy week in space news, and very little of it was good. We’ll start with the one winner of the week, Firefly’s Blue Ghost Mission 1, which landed successfully on the Moon’s surface on March 2. The lander is part of NASA’s Commercial Lunar Payload Services program and carries ten scientific payloads, including a GPS/GNSS receiver that successfully tracked signals from Earth-orbiting satellites. All of the scientific payloads have completed their missions, which is good because the lander isn’t designed to withstand the long, cold lunar night only a few days away. The landing makes Firefly the first commercial outfit to successfully soft-land something on the Moon, and being the first at anything is always a big deal.

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Deep Drawing With Ultrasonics

Small cylindrical parts are often formed through deep drawing — a process by which a punch forms the finished piece from a flat sheet of metal using a forming die. If it sounds like that stresses the metal, it does. But researchers at Fraunhofer have found a way to reduce friction protecting both the material and the tools that do the forming. The process — known as VibroDraw — uses ultrasonic vibrations at around 500 Hz.

Researchers claim a 20% reduction in friction now, and it may be possible to go even further. With less friction, it is possible to do a deeper draw in a single stage. It also creates less heat which is good for tool life and prevents overheating lubricant. The process has a patent if you want more details. You might need to brush up on your German, though. Unsurprisingly, the vibrations are from a piezoelectric transducer.

Copper is soft enough to use 3D printed dies. We don’t know if this technique would help with that or not. Then there’s hydroforming. If you have any results using ultrasonics with these or any other techniques, be sure to let us know.