Usagi’s PDP-11 Supercomputer And Appeal For Floating Point Systems Info

January 12, 2025 by 22 Comments

With an exciting new year of retrocomputing ahead for [David Lovett] over at the Usagi Electric YouTube channel, recently some new hardware arrived at the farm. Specifically hardware from a company called Floating Point Systems (FPS), whose systems provide computing features to assist e.g. a minicomputer like [David]’s PDP-11/44 system with floating point operations. The goal here is to use a stack of 1980s-era FPS hardware to give the PDP-11/44 MIMD (multiple instructions, multiple data) computing features, which is a characteristic associated with supercomputers.

The FPS hardware is unfortunately both somewhat rare and not too much documentation, including schematics, has been found so far. This is where [David] would love some help from the community on finding more FPS hardware, documentation and any related information so that it can all be preserved.

FPS itself was acquired by Cray in 1991, before SGI took over Cray Research in 1996. As is usual with such acquisitions, a lot of older information tends to get lost, along with the hardware as it gets tossed out over the years by companies and others. So far [David] has acquired an FPS-100 array processor, an interface card for the PDP-11 and an FPS-3000, the latter of which appears to be a MIMD unit akin to the FPS-5000.

Without schematics, let alone significant documentation, it’s going to be an uphill battle to make it all work again, but with a bit of help from us retrocomputer enthusiasts, perhaps this might not be as impossible after all.

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Second CNC Machine Is Twice As Nice

January 12, 2025 by 10 Comments

[Cody Lammer] built a sweet CNC router. But as always, when you build a “thing”, you inevitably figure out how to build a better “thing” in the process, so here we are with Cody’s CNC machine v2.0. And it looks like CNC v1.0 was no slouch, so there’s no shortage of custom milled aluminum here.

The standout detail of this build is that almost all of the drive electronics and logic are hidden inside the gantry itself, making cabling a lot less of a nightmare than it usually is. While doing this was impossible in the past, because everything was just so bulky, he manages to get an ESP32 and the stepper drivers onto a small enough board that it can move along with the parts that it controls. FluidNC handles the G-Code interpretation side of things, along with providing a handy WiFi interface. This also allows him to implement a nice jog wheel and a very handy separate position and status indicator LCD on the gantry itself.

When you’re making your second CNC, you have not only the benefit of hindsight, but once you’ve cut all the parts you need, you also have a z-axis to steal and just bolt on. [Cody] mentions wanting a new z-axis with more travel – don’t we all! – but getting the machine up and running is the first priority. It’s cool to have that flexibility.

All in all, this is a very clean build, and it looks like a great improvement over the old machine. Of course, that’s the beauty of machine tools: they are the tools that you need to make the next tool you need. Want more on that subject? [Give Quinn Dunki’s machining series a read].

Fraens’ New Loom And The Limits Of 3D Printing

January 12, 2025 by 8 Comments

[Fraens] has been re-making industrial machines in fantastic 3D-printable versions for a few years now, and we’ve loved watching his creations get progressively more intricate. But with this nearly completely 3D-printable needle loom, he’s pushing right up against the edge of the possible.

The needle loom is a lot like the flying shuttle loom that started the Industrial Revolution, except for making belts or ribbons. It’s certainly among the most complex 3D-printed machines that we’ve ever seen, and [Fraens] himself says that it is pushing the limits of what’s doable in plastic — for more consistent webbing, he’d make some parts out of metal. But that’s quibbling; this thing is amazing.

There are mechanical details galore here. For instance, check out the cam-chain that raises, holds, and lowers arms to make the pattern. Equally important are the adjustable friction brakes on the rollers that hold the warp, that create a controlled constant tension on the strings.  (Don’t ask us, we had to Wikipedia it!) We can see that design coming in handy in some of our own projects.

On the aesthetic front, the simple but consistent choice of three colors for gears, arms, and frame make the build look super tidy. And the accents of two-color printing on the end caps is just the cherry on the top.

This is no small project, with eight-beds-worth of printed parts, plus all the screws, bearings, washers, etc. The models are for pay, but if you’re going to actually make this, that’s just a tiny fraction of the investment, and we think it’s going to a good home.

We are still thinking of making [Fraens]’s vibratory rock tumbler design, but check out all of his work if you’re interested in nice 3D-printed mechanical designs.

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It’s A Bench, But It’s Not Benchy

January 12, 2025 by 27 Comments

Whatever the nuances are surrounding the reported taking down of remixes derived from the famous Benchy 3D printer stress test, it was inevitable that in its aftermath there would be competing stress tests appear under more permissive licensing. And so it has come to pass, in the form of [Depep1]’s Boaty, a model that’s not a boat, but a bench. Sadly this is being written away from a 3D printer so we can’t try it, but we can immediately see that its low bed contact area from having spindly legs would be a significant test for many printers’ bed adhesion, and it has overhangs and bridges aplenty.

It’s always interesting to see new takes on a printer stress test, after all we can all use something to check the health of our machines. But the Benchy saga isn’t something we think should drive you away from the little boat we know and love, as it remains an open-source model as it always has been. We don’t know the exact reasons why the derivatives were removed, but we understand from Internet scuttlebut that the waters may be a little more cloudy than at first supposed. If there’s any moral at all to the story, it lies in reading and understanding open source licences, rather than just assuming they all allow us to do anything we want.

Meanwhile it’s likely this model will be joined by others, and we welcome that. After all, innovation should be part of what open source does.

Missed the Benchy takedown story? Catch up here.

Thanks [Jeremy G] for the tip.

Bad Apple But It’s 6,500 Regex Searches In Vim

January 11, 2025 by 7 Comments

In the world of showing off, there is alongside ‘Does it play Doom?’ that other classic of ‘Does it play Bad Apple?’. Whereas either would be quaint in the context of the Vim editor, this didn’t deter [Nolen Royalty] from making Vim play the Bad Apple video. As this is a purely black and white video, this means that it’s possible to convert each frame into a collection of pixels, with regular expression based search and custom highlighting allowing each frame to be rendered in the Vim window.

The fun part about this hack is that it doesn’t require any hacking or patching of Vim, but leans on its insane levels of built-in search features by line and column, adjusting the default highlight features and using a square font to get proper pixels rather than rectangles. The font is (unsurprisingly) called Square and targets roguelike games with a specific aesthetic.

First 6,500 frames are fed through ffmpeg to get PNGs, which are converted these into pixel arrays using scripts on the GitHub project. Then the regex search combined with Vim macros allowed the video to be played at real-time speed, albeit at 120 x 90 resolution to give the PC a fighting chance. The highlighting provides the contrast with the unlit pixels, creating a rather nice result as can be seen in the embedded video.

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Retrotechtacular: The 1951 Telephone Selector

January 11, 2025 by 20 Comments

Telephone systems predate the use of cheap computers and electronic switches. Yesterday’s phone system used lots of stepping relays in a box known as a “selector.” If you worked for the phone company around 1951, you might have seen the Bell System training film shown below that covers 197 selectors.

The relays are not all the normal ones we think of today. There are slow release relays and vertical shafts that are held by a “dog.” The shaft moves to match the customer’s rotary dial input.

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IFixit Releases Command Line Docs For FixHub Iron

January 11, 2025 by 16 Comments

When we reviewed the iFixit FixHub back in September, one of the most interesting features of the portable soldering station was the command line interface that both the iron and the base station offered up once you connected to them via USB. While this feature wasn’t documented anywhere, it made a degree of a sense, as the devices used WebSerial to communicate with the browser. What was less clear at the time was whether or not the user was supposed to be fiddling with this interface, or if iFixit intended to lock it up in a future firmware update.

Thanks to a recent info dump on GitHub, it seems like we have our answer. In the repo, iFixit has provided documentation for each individual command on both the iron and base, including some background information and application notes for a few of the more esoteric functions. A handful of the commands are apparently disabled in the production version of the firmware, but there’s still plenty to poke around with.

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