RepRap was the origin of pushing hobby 3D printing boundaries, and here we see a RepRap scaled down to the smallest detail. [Vik Olliver] over at the RepRap blog has been working on getting a printer working printing down to the level of micron accuracy.

The printer is constructed using 3D printed flexures similar to the OpenFlecture microscope. Two flexures create the XYZ movement required for the tiny movements needed for micron level printing. While still in the stages of printing simple objects, the microscopic scale of printing is incredible. [Vik] managed to print a triangular pattern in resin at a total size of 300 µm. For comparison SLA 3D printers struggle at many times that scale. Other interesting possibilities from this technology could be printing small scale circuits from conductive resins, though this might require some customization in the resin department.

In addition to printing with resin, µRepRap can be seen making designs in marker ink such as our own Jolly Wrencher! At only 1.5 mm the detail is impressive especially when considering the nature of scratching away ink.

If you want to make your own µRepRap head over to [Vik Olliver]’s GitHub. The µRepRap project has been a long going project. From the time it started the design has changed quite a bit. Check out an older version of the µRepRap project based around OpenFlexture!

hackaday.com/2025/04/21/jolly-…

A recent project over on Hackaday.io from [Michael Gardi] is Trekulator – Where No Maker Has Gone Before.

This is a fun build and [Michael] has done a very good job of emulating the original device. [Michael] used the Hackaday.io logging feature to log his progress. Starting in September 2024 he modeled the case, got his original hardware working, got the 7-segment display working, added support for sound, got the keypad working and mounted it, added the TFT display and mounted it, wired up the breadboard implementation, designed and implemented the PCBs, added some finishing touches, installed improved keys, and added a power socket back in March.

It is perhaps funny that where the original device used four red LEDs, [Michael] has used an entire TFT display. This would have been pure decadence by the standards of 1977. The software for the ESP32 microcontroller was fairly involved. It had to support audio, graphics, animations, keyboard input, the 7-segment display, and the actual calculations.

The calculations are done using double-precision floating-point values and eight positions on the display so this code will do weird things in some edge cases. For instance if you ask it to sum two eight digit numbers as 90,000,000 and 80,000,000, which would ordinarily sum to the nine digit value 170,000,000, the display will show you a different value instead, such as maybe 17,000,000 or 70,000,000. Why don’t you put one together and let us know what it actually does! Also, can you find any floating-point precision bugs?

This was a really fun project, thanks to [Michael] for writing it up and letting us know via the tips line!

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hackaday.com/2025/04/21/trekul…

Long before the Java Virtual Machine (JVM) was said to take the world by storm, the p-System (pseudo-system, or virtual machine) developed at the University of California, San Diego (UCSD) provided a cross-platform environment for the UCSD’s Pascal dialect. Later on, additional languages would also be made available for the UCSD p-System, such as Fortran (by Apple Computer) and Ada (by TeleSoft), not unlike the various languages targeting the JVM today in addition to Java. The p-System could be run on an existing OS or as its own OS directly on the hardware. This was extremely attractive in the fragmented home computer market of the 1980s.

After the final release of version IV of UCSD p-System (IV.2.2 R1.1) in 1987, the software died a slow death, but this doesn’t mean it is forgotten. People like [Hans Otten] have documented the history and technical details of the UCSD p-System, and the UCSD Pascal dialect went on to inspire Borland Pascal.

Recently [Mark Bessey] also reminisced about using the p-System in High School with computer programming classes back in 1986. This inspired him to look at re-experiencing Apple Pascal as well as UCSD Pascal on the UCSD p-System, possibly writing a p-System machine. Even if it’s just for nostalgia’s sake, it’s pretty cool to tinker with what is effectively the Java Virtual Machine or Common Language Runtime of the 1970s, decades before either of those were a twinkle in a software developer’s eyes.

Another common virtual runtime of the era was CHIP-8. It is also gone, but not quite forgotten.

hackaday.com/2025/04/21/rememb…

If you do a lot of 3D computer work, I hear a Spacemouse is indispensable. So why not build a keyboard around it and make it a mouse-cropad?

Image by [DethKlawMiniatures] via redditThat’s exactly what [DethKlawMiniatures] did with theirs. This baby is built with mild steel for the frame, along with some 3D-printed spacers and a pocket for the Spacemouse itself to live in.

Those switches are Kailh speed coppers, and they’re all wired up to a Seeed Xiao RP2040. [DethKlawMiniatures] says that making that lovely PCB by hand was a huge hassle, but impatience took over.

After a bit of use, [DethKlawMiniatures] says that the radial curve of the macro pad is nice, and the learning curve was okay. I think this baby looks fantastic, and I hope [DethKlawMiniatures] gets a lot of productivity out of it.

Kinesis Rides Again After 15 Years

Fifteen years ago, [mrmarbury] did a lot of ergo keyboard research and longed for a DataHand II. Once the sticker shock wore off, he settled on a Kinesis Advantage with MX browns just like your girl is typing on right now.

Image by [mrmarbury] via redditNot only did [mrmarbury] love the Kinesis to death, he learned Dvorak on it and can do 140 WPM today. And, much like my own experience, the Kinesis basically saved his career.

Anyway, things were going gangbusters for over a decade until [mrmarbury] spilled coffee on the thing. The main board shorted out, as did a thumb cluster trace. He did the Stapelberg mod to replace the main board, but that only lasted a little while until one of the key-wells’ flex boards came up defective. Yadda yadda yadda, he moved on and eventually got a Svalboard, which is pretty darn close to having a DataHand II.

But then a couple of months ago, the Kinesis fell on [mrmarbury]’s head while cleaning out a closet and he knew he had to fix it once and for all. He ripped out the flex boards and hand-wired it up to work with the Stapelberg mod. While the thumb clusters still have their browns and boards intact, the rest were replaced with Akko V3 Creme Blue Pros, which sound like they’re probably pretty amazing to type on. So far, so good, and it has quickly become [mrmarbury]’s favorite keyboard again. I can’t say I’m too surprised!

The Centerfold: Swingin’ Bachelor Pad

Image by [weetek] via redditIsn’t this whole thing just nice? Yeah it is. I really like the lighting and the monster monstera. The register is cool, and I like the way it the panels on the left wall mimic its lines. And apparently that is a good Herman Miller chair, and I dig all the weird plastic on the back, but I can’t help but think this setup would look even cleaner with an Aeron there instead. (Worth every penny!)

Do you rock a sweet set of peripherals on a screamin’ desk pad? Send me a picture along with your handle and all the gory details, and you could be featured here!

Historical Clackers: the IBM Selectric Composer

And what do we have here? This beauty is not a typewriter, exactly. It’s a typesetter. What this means is that, if used as directed, this machine can churn out text that looks like it was typeset on a printing press. You know, with the right margin justified.

Image by [saxifrageous] via redditYou may be wondering how this is achieved at all. It has to do with messing with the kerning of the type — that’s the space between each letter. The dial on the left sets the language of the type element, while the one one the right changes the spacing. There’s a lever around back that lets you change the pitch, or size of the type. The best part? It’s completely mechanical.

To actually use the thing, you had to type your text twice. The first time, the machine measured the length of the line automatically and then report a color and number combination (like red-5) which was to be noted in the right margin.

The IBM Selectric Composer came out in 1966 and was a particularly expensive machine. Like, $35,000 in 2025 money expensive. IBM typically rented them out to companies and then trashed them when they came back, which, if you’re younger than a certain vintage, is why you’ve probably never seen one before.

If you just want to hear one clack, check out the short video below of a 1972 Selectric Composer where you can get a closer look at the dials. In 1975, the first Electronic Selectric Composer came out. I can’t even imagine how much those must have cost.

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Finally, a Keyboard Part Picker

Can’t decide what kind of keyboard to build? Not even sure what all there is to consider? Then you can’t go wrong with Curatle, a keyboard part picker built by [Careless-Pay9337] to help separate you from your hard-earned money in itemized fashion.

The start screen for Curatle made by [Careless-Pay9337].So this is basically PCPartPicker, but for keyboards, and those are [Careless-Pay9337]’s words. Essentially, [Careless-Pay9337] scraped a boatload of keyboard products from various vendors, so there is a lot to choose from already. But if that’s not enough, you can also import products from any store.

The only trouble is that currently, there’s no compatibility checking built in. It’ll be a long road, but it’s something that [Careless-Pay9337] does plan to implement in the future.

What else would you like to see? Be sure to let [Careless-Pay9337] know over in the reddit thread.

Got a hot tip that has like, anything to do with keyboards? Help me out by sending in a link or two. Don’t want all the Hackaday scribes to see it? Feel free to email me directly.

hackaday.com/2025/04/21/keebin…

Although the video game crash of the mid-80s caused a major decline in arcades from their peak popularity, the industry didn’t completely die off. In fact, there was a revival that lasted until the 90s with plenty of companies like Capcom, Midway, SEGA, and Konami all competing to get quarters, francs, loonies, yen, and other coins from around the world. During this time, Namco — another game company — built a colossal 28-player prototype shooter game. Eventually, they cut it down to a (still titanic) six-player game that was actually released to the world. [PhilWIP] and his associates are currently restoring one of the few remaining room-sized games that are still surviving.

The game is called Galaxian 3, with this particular one having been upgraded to a version called “Attack of the Zolgear”. Even though it’s “only” a six-person shooter, it’s still enormous in scale. The six players sit side-by-side in an enclosed room, each with their own controller. Two projectors handle the display, which is large even by modern standards, and a gauntlet of early-90s technology, including LaserDisc players, is responsible for all of the gameplay. When [PhilWIP] first arrived, the game actually powered on, but there were several problems to solve before it was playable. They also wanted to preserve the game, which meant imaging the LaserDiscs to copy their data onto modern storage. Some of the player input PCBs needed repairs, and there were several issues with the projectors. Eventually the team got the system working well enough to play.

[PhilWIP] and the others haven’t gotten all the issues ironed out yet. The hope is that subsequent trips will restore this 90s novelty to working order shortly. It turns out there were all kinds of unique hardware from this wild-west era that’s in need of restoring, as we saw a few years ago with this early 3D cabinet from the same era.

hackaday.com/2025/04/21/restor…

E buona Pasqua, riempiamoci la bocca di Pace.

Gli Usa avvertono, 'senza una svolta su Kiev ci sfiliamo'

Fonte: ANSA
search.app/dRKGm

Nella loro eleganza, i mici sono diventati discreti guardiani del parco, custodi ideali di un passato che ancora parla.

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#gatti

A rendere la questione piuttosto complicata è il fatto che la terapia familiare è una pratica continuamente in cambiamento, la teoria sistemica applicata alla psicoterapia è da sempre costantemente in cerca di un modo per superarsi. Dalla sua alba questa pratica si è presentata come inquieta e instabile. Diversamente da quanto accade per altri approcci terapeutici, un sistemico che passasse qualche anno su un’isola deserta, al ritorno difficilmente troverebbe tutto come prima.
O almeno è stato così per una fetta importante della sua storia. Questo si deve, credo, a due ragioni soprattutto...

Dal mio blog di psicoterapia:
massimogiuliani.it/blog/2025/0…

Cosa si insegna e, soprattutto, cosa no (nuove note su integrazioni ed eclettismi) - Corpi che parlano, il blog

"La terapia familiare ha senza dubbio cambiato notevolmente le pratiche di salute mentale, ma in qualche modo ha perso per strada gran parte dell'antica eccitazione (...) Che ne è stato di quell'idea straordinariamente nuova, di quell'audace salto

^{massimo giuliani (Corpi che parlano, il blog)}