Shipping Your Illicit Software On Launch Hardware

June 13, 2024 by 17 Comments

In the course of a career, you may run up against projects that get cancelled, especially those that are interesting, but deemed unprofitable in the eyes of the corporate overlords. Most people would move, but [Ron Avitzur] just couldn’t let it go.

In 1993, in the midst of the transition to PowerPC, [Avitzur]’s employer let him go as the project they were contracted to perform for Apple was canceled. He had been working on a graphing calculator to show off the capabilities of the new system. Finding his badge still allowed him access to the building, he “just kept showing up.”

[Avitzur] continued working until Apple Facilities caught onto his use of an abandoned office with another former contractor, [Greg Robbins], and their badges were removed from the system. Not the type to give up, they tailgated other engineers into the building to a different empty office to continue their work. (If you’ve read Kevin Mitnick‘s Ghost in the Wires, you’ll remember this is one of the most effective ways to gain unauthorized access to a building.)

We’ll let [Avitzur] tell you the rest, but suffice it to say, this story has a number of twists and turns to it. We suspect it certainly isn’t the typical way a piece of software gets included on the device from the factory.

Looking for more computing history? How about a short documentary on the Aiken computers, or a Hack Chat on how to preserve that history?

[Thanks to Stephen for the tip via the Retrocomputing Forum!]

Marimbatron: A Digital Marimba Prototyping Project

June 13, 2024 by 6 Comments

The Marimbatron is [Leo Kuipers] ‘s final project as part of the Fab Academy program supervised by [Prof. Neil Gershenfeld] of MIT’s Center for Bits and Atoms. The course aims to teach students how to leverage all the fab lab skills to create unique prototypes using the materials at hand.

The final polyurethane/PET/Flex PCB stack-up for the sensor pad

Fortunately, one of the main topics covered in the course is documentation, and [Leo] has provided ample material for review. The marimba consists of a horizontal series of wooden bars, each mounted over a metal resonator tube. It is played similarly to the xylophone, with a piano-type note arrangement, covering about five octaves but with a lower range than the xylophone. [Leo] converted this piano-type layout into a more logical grid arrangement. The individual pads are 3D printed in PETG and attached to a DIY piezoresistive pressure sensor made from a graphite-sprayed PET sheet laid upon a DIY flexible PCB. A central addressable LED was also included for indication purposes. The base layer is made of cast polyurethane, formed inside a 3D-printed rigid mould. This absorbs impact and prevents crosstalk to nearby sensors. The sensor PCB was initially prototyped by adhering a layer of copper tape to a layer of Kapton tape and cutting it out using a desktop vinyl cutter. While this method worked for the proof of concept, [Leo] ultimately outsourced the final version to a PCB manufacturer. The description of prototyping the sensor and dealing with over-moulding was particularly fascinating.

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A 1940s Car Radio Receives Some Love

June 13, 2024 by 9 Comments

The entertainment systems in modern vehicles is akin to a small in-dash computer, and handles all manner of digital content. It probably also incorporates a radio, but increasingly that’s treated as something of an afterthought. There was a time though when any radio in a car was a big deal, and if you own a car from that era it’s possible that you’ve had to coax an aged radio into life. [The Radio Mechanic] is working on a radio from a 1946 Packard, which provides a feast for anyone with a penchant for 1940s electronics.

The unit, manufactured by Philco, is an all-in-one, with a bulky speaker in the chassis alongside the tubes and other components. It would have sat behind the dash in the original car, so some external cosmetic damage is not critical. Less easy to pass off is the cone rubbing on the magnet, probably due to water damage over the last eight decades. Particularly interesting are the controls, as we’re rather enamored with the multicolored filter attached to the tone control. A laser cutter makes short work of recreating the original felt gasket here.

The video below is the first of a series on this radio, so we don’t see it working. Ahead will be a lot more cleaning up and testing of components, and we’d expect a lot of those paper capacitors to need replacement. We can almost smell that warm phenolic smell.

If tube radio work is your thing, we’ve been there before.

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TDS 744A Scope Teardown Fixes Dodgy Channel

June 13, 2024 by 1 Comment

There are a lot of oscilloscopes from around the 1990s which are still very much desirable today, such as the Tektronix TDS 744A which [DiodesGoneWild] got his grubby mitts on. This is a 500 MHz, 4-channel scope, with a capture rate of 500 MS/s (4 channels) to 2 GS/s (1 channel). It also has a color display and even comes with a high-density (1.44 MB) floppy drive. Unfortunately this particular unit was having trouble with its fourth channel, and its NuColor display had degraded, something that’s all too common with this type of hybrid CRT/LCD (LCCS) technology.

Starting with a teardown of the unit to inspect the guts, there was no obvious damage on the PCBs, nor on the acquisition board which would explain the weird DC offset on the fourth channel. After cleaning and inspecting the capture module and putting the unit back together, the bias seen on channel four seemed to disappear. A reminder that the best problems are the ones that solve themselves. As for the NuColor display, this uses a monochrome CRT (which works fine) and an LCD with color filters. It’s the latter which seems degraded on this unit, with a repair still being planned.

We covered NuColor-based devices before, which offer super-sharp details that are hard to capture even with modern-day LCDs, never mind the ones of the 90s. Fixing these NuColor displays can be easy-ish sometimes, as [JVG] found when tearing apart a very similar Tektronix TDX-524A which required a power supply fix and the removal of goopy gel between the CRT and LCD to restore it.

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PCB Design Review: A 5V UPS With LTC4040

June 13, 2024 by 23 Comments

Do you have a 5 V device you want to run 24/7, no matter whether you have electricity? Not to worry – Linear Technology has made a perfect IC for you, the LTC4040; with the perfect assortment of features, except perhaps for the hefty price tag.

[Lukilukeskywalker] has shared a PCB for us to review – a LTC4040-based stamp you can drop onto your PCB whenever you want a LTC4040 design. It’s a really nice module to see designed – things like LiFePO4 support make this IC a perfect solution for many hacker usecases. For instance, are you designing a custom Pi HAT? Drop this module to give your HAT the UPS capability for barely any PCB effort. if your Pi or any other single-board computer needs just a little bit of custom sauce, this module spices it up alright!

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Long-Awaited SLS4All 3D Printer Now Shipping

June 13, 2024 by 35 Comments

We touched on the open source SLS4All DIY SLS 3D printer a year or two ago when the project was in the early stages. Finally, version one is complete, with a parts kit ready to ship and all design data ready for download if a DIY build or derivative is your style. As some already mentioned, this is not going to be cheap: with the full parts kit running at an eye-watering $7K before tax. But it’s possible to build or source almost all of it a bit at a time for those on a budget.

Try printing THIS benchy on an FDM machine!

It’s important to note that to access the detailed information, you’ll need to create an account, which is a bit inconvenient for an open source design. However, all the essential components seem to be available, so it’s forgivable. In terms of electronics, there are two custom PCBs: the GATE1 (GAlvo and Temperature Control) and the ZERO1 (Zero-crossing dimming) controller. Other than that, all the electronics seem to be standard off-the-shelf components. Both of these PCBs are designed using EasyEDA.

Unfortunately we couldn’t find access to the PCB Gerbers, nor does there appear to be a link to their respective EasyEDA projects, just the reference schematics. This is a bit of a drawback, but it’s something that could easily be reproduced with enough motivation. Control is courtesy of a Radxa Rock Pi, as there were ‘problems’ with a Raspberry Pi. This is paired with a 7-inch touchscreen to complete the UI. This is running a highly modified version of the Klipper together with their own control software, which is still undergoing testing before release.

The laser head is built around a 10 W 450 nm laser module from China and a high-end galvanometer set. Two 200 W halogen tube heaters heat the print bed, and 200 W silicone heating pads heat both the powder bed and the print bed.

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Raspberry Pi Saves Printer From Junk Pile

June 13, 2024 by 53 Comments

Around here, printers have a life expectancy of about two years if we are lucky. But [techtipsy] has a family member who has milked a long life from an old Canon PIXMA printer. That is, until Microsoft or Canon decided it was too old to print anymore. With Windows 10, it took some hacking to get it to work, but Windows 11 was the death knell. Well, it would have been if not for [techtipsy’s] ingenuity with a Raspberry Pi.

The Pi uses Linux, and, of course, Linux will happily continue to print without difficulty. If you are Linux savvy, you can probably see where this is going.

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