Day: January 23, 2024

Crusty: The Story Of The Mac SE That Could

January 23, 2024 by 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?

Crusty’s mainboard as found

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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Cockpit of a Hawker Siddeley Trident with the moving map display

A Live Map Display In A 1960s Airliner

January 23, 2024 by 4 Comments

We tend take GPS navigation for granted these days, so it’s easy to forget that it became only available in the last few decades. Aviation navigation used to be significantly more challenging, so how was the Hawker Siddeley Trident, a 1960s airliner, fitted with a live updating map display? In a fascinating dive into aviation history the British Airliner Collection has spun up an insightful article on the magic behind these moving map displays.

Without access to satellite navigation or advanced electronics, engineers had to get creative. Enter the Trident’s moving map display, a marvel of ingenuity that predated the GPS systems. Using a combination of Doppler radar and some clever mechanics, pilots could accurately determine their position without relying on any external signals.

The system makes use of four Doppler radar beams, arranged in what was known as the Janus array. This configuration corrected for errors caused by changes in altitude or wind drift, ensuring accurate ground speed readings. The movable antennas mounted under the cabin floor could adjust its orientation to maintain alignment with the actual direction of travel, calculating drift angle precisely. Combined with compass information and flight time from a known start point to to indicate the current position with a pointer on a rolled paper map. The system was well ahead of it’s time, and significantly easier to use and more accurate than the Decca radio navigation system in use at the time.

It’s mind boggling to see the solutions engineers came up with without much of the digital technology we take for granted today. Gyroscopes for inertial navigation, the cavity magnetron for radar and radial engines were all building blocks for modern aviation.

Thanks for the tip [poiuyt]!

Reverse Engineering The Apple Touch Bar Screen

January 23, 2024 by 10 Comments

The Apple Touch Bar was an oddity on a fairly small number of Apple laptops which replaced the function key row with a touch display. Yet what is special about this display other than its odd form factor when you consider it as a generic touch display? As [Wenting Zhang] describes in a recent reverse-engineering video, this 2,170 x 60 pixel display is somewhat limited in that it doesn’t support the MIPI DSI video mode, only command mode, along with a special instruction (0x3C) for automatic address offsets. The results of this project can be found on the GitLab account.

In a way these limitations make sense when you consider Apple’s use case for these special MIPI-DSI displays. As a touch screen with dynamic controls being displayed on it, features such as video playback never were a goal, and thus Apple likely decided to save a few bucks, possibly also due to MIPI licensing costs. What this means is that if you had dreamed of snapping up an extremely long and narrow OLED display for a video project you’re in for somewhat of a bad time. Although animated content is possible – as [Wenting] demonstrates – this comes with all the limitations of command mode, meaning slower updates, higher power usage and a lot more overhead.

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Autofeeding CNC Lathe Cranks Out Parts All By Itself

January 23, 2024 by 18 Comments

The trouble with building a business around selling low-margin widgets is that you have to find a way to make a lot of them to make it worth your while. And if the widget in question is labor-intensive to make, you’ve got to find ways to reduce your inputs. That sounds like a job for industrial automation, a solution that’s often out of reach of small shops, for all the obvious reasons. Not if you’re clever about things, though, as this fully automated CNC lathe work cell shows.

This build comes to us from the woodshop of [Maher Lagha], where he’s making wooden honey dippers. Wooden dowel blanks are dispensed from an infeed rack and chucked between centers on the headstock and pneumatic tailstock. A two-axis stage in front of the workpiece moves a tool against the spinning stock, carving out the honey dipper in just a few minutes. When the lathe work is done, the spindle stops, the tailstock pulls the honey dipper back off the headstock, and a pneumatic piston unceremoniously whacks the almost-finished part — it looks like it still needs a little manual post-processing — into a bin. Lather, rinse, repeat, profit.

[Maher] doesn’t provide many details, but just looking at the work cell shows a veritable feast of industrial automation equipment. The spindle and tailstock of the lathe sit on a bed made from a massive slab of aluminum extrusion, and the X- and Y-axes use linear rails and ballscrews. And mindful of the effects of wood chips on delicate mechanisms, [Maher] did a good job of containing the mess with a host of acrylic guards.

As we said when we saw [Maher]’s wooden coaster work cell a while back, the wood widget business must be pretty good to justify automation like this. What’s nice with both these rigs is that they look like they could be quickly reprogrammed and retooled to create other products. Pretty impressive.

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Testing Your C Knowledge With This One Simple Quiz

January 23, 2024 by 53 Comments

One of the most exciting aspects of the C programming language — as effectively high-level assembly — is that although it’s a bit friendlier for the developer, it also adds a lot of required know-how on account of its portability across platforms and architectures. This know-how is what [Oleksandr Kaleniuk] manages to wonderfully illustrate with a simple 5-question, multiple-choice quiz on what the return value is of the provided function snippets of C code. How well do you know C?

For those who have had their run-ins with C directly (or indirectly via the support for it in languages like C++) the words ‘undefined behavior‘ (UB) are likely to induce a nervous twitch or two, along with a suspicious glance at whichever parts of reality are about to evaporate and destabilize the Universe this time. Although it is said that a proper C program is written with zero UB cases in it, in practice this can be rather tough, even before considering the other exciting ways in which a piece of code can fail to do the expected thing.

For languages other than C this is of course also a challenge, which is the reason why certification programs for e.g. avionics go out of their way to weed out such preventable issues, and only few programming languages like Ada (anything avionics, medical, etc.) and C++ (F-35 and other US DoD projects) make it into devices where failure is literally not an option.

Could Solar-Powered Airships Offer Cleaner Travel?

January 23, 2024 by 93 Comments

The blimp, the airship, the dirigible. Whatever you call them, you probably don’t find yourself thinking about them too often. They were an easy way to get airborne, predating the invention of the airplane by decades. And yet, they suffered—they were too slow, too cumbersome, and often too dangerous to compete once conventional planes hit the scene.

And yet! Here you are reading about airships once more, because some people aren’t giving up on this most hilarious manner of air travel. Yes, it’s 2024, and airship projects continue apace even in the face of the overwhelming superiority of the airplane.

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Is This The World’s Smallest N-Scale Train Layout?

January 23, 2024 by 7 Comments

There’s just something about miniature worlds — they’re just so relaxing to look at and ponder. Think you don’t have ample room for a model train layout at your place? You may not be thinking small enough. [Peter Waldraff] knows a thing or two about hiding train layouts inside of furniture (that’s one solution), but this time, he’s built a track in plain sight that’s meant to sit on the bookshelf. The whole thing is just 5.5″ x 12″.

This N-scale layout was three years in the making, mostly because [Peter] was waiting for just the right little powered chassis to come along. For the layout, [Peter] started by creating custom flexible track by removing pieces with a sharp knife. He glued down the track to pink foam and used nails to hold it in place while the glue dried. He also built a wood frame around the base to stabilize it and hold some of the electronic components, including a switch made from an old ballpoint pen.

Then it was time to start decorating the thing, beginning with a couple of buildings made from more pink foam that are both lit up with LEDs. Eventually, [Peter] added a bunch of details like streetlights, animals, and garbage cans that really make the layout pop. As far as the engine goes, [Peter] picked up a Tomytec TM-TR02 on eBay and built a trolley out of two broken cars. [Peter]’s build is something you just have to see for yourself — fortunately for you, the build and demo video is after the break.

Like we said, [Peter]’s usual territory is hiding train layouts in end tables and coffee tables and the like, so it’s nice to see what he can do given different constraints.

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