Restoring A Dead Commodore 128DCR

Another day, another retro computer lovingly restored to like-new condition by [Drygol]. This time, the subject of his attention is a Commodore 128DCR that earned every bit of the “For Parts, Not Working” condition it was listed under. From a spider infestation to a cracked power supply PCB, this computer was in quite a state. But in the end he got the three decade old machine back in working condition and even managed to teach it a few new tricks along the way.

Obviously the shattered PSU was the most pressing issue with the Commodore. Interestingly, the machine still had its warranty seal in place on the back, so whatever happened to this PSU seems to have occurred without human intervention.

Rather than just replacing the PSU, [Drygol] first pieced the board back together with the help of cyanoacrylate glue, and then coated the top with an epoxy resin to give it some mechanical strength. On the back side the traces were either repaired or replaced entirely with jumper wires where the damage was too severe.

With the PSU repaired and tested, he moved on to cleaning the computer’s main board and whitening all the plastic external components. Even the individual keycaps took a bath to get them looking like new again. This put the computer in about as close to like-new condition as it could get.

But why stop there? He next installed the JiffyDOS modification to improve system performance, and wired in an adapter that lets the computer output a crisp 80 columns over S-Video. It’s safe to say this particular Commodore is in better shape now than it was when it rolled off the assembly line.

While an impressive enough final result, this is still fairly tame for [Drygol]. If you want to see a real challenge, take a look at the insane amount of work that went into recreating this smashed Atari 800XL case.

ATX2AT Makes Retrocomputing Safer, Heads To Kickstarter

It’s easy to take power supplies for granted in modern computing, but powering vintage hardware is not always so simple or worry-free. The power supplies for old electronics are themselves vintage, and the hardware being powered can be quite precious. A power problem can easily cause fried components and burned traces on a board. As [Doc TB] observes, by the time you hear crackling, it’s already far too late.

To address this, [Doc TB] designed the ATX2AT Smart Converter as an open source project and recently decided to make it available through a Kickstarter campaign. ATX2AT is a way to safely and securely replace some vintage power supplies with a standard PC ATX power supply, and adds a large number of protection features such as current monitoring and programmable reaction time for overcurrent protection. All of this can help prevent a retrocomputer enthusiast’s precious vintage hardware from being damaged in the event of a problem. It’s not just for powering known-good hardware; it can be invaluable when testing or repairing hardware that might be in an unknown state.

When we first came across [Doc TB]’s ATX2AT project we recognized it as a well-made device to address a specific niche, and to do it well. Assessing risk takes into account not only the probability of a problem occurring, but also just how bad things would be if it did happen. If your old hardware is precious enough to warrant the extra protection, or you are into repairing or assessing old hardware, then an ATX2AT might be just what you need. You can see it in action in the video embedded below.

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USB Power Delivery For All The Things

The promise of USB Power Delivery (USB-PD) is that we’ll eventually be able to power all our gadgets, at least the ones that draw less than 100 watts anyway, with just one adapter. Considering most of us are the proud owners of a box filled with assorted AC/DC adapters in all shapes and sizes, it’s certainly a very appealing prospect. But [Mansour Behabadi] hasn’t exactly been thrilled with the rate at which his sundry electronic devices have been jumping on the USB-PD bandwagon, so he decided to do something about it.

[Mansour] wanted a simple way to charge his laptop (and anything else he could think of) with USB-PD over USB-C, but none of the existing options on the market was quite what he wanted. He looked around and eventually discovered the STUSB4500, a a USB power delivery controller chip that can be configured over I2C.

With a bit of nonvolatile memory onboard, it can retain its settings so he didn’t have to include a microcontroller in his design: just program it once and it can be used stand-alone to negotiate the appropriate voltage and current requirements when its plugged in.

The board that [Mansour] came up with is a handy way of powering your projects via USB-C without having to reinvent the wheel. Using the PC configuration tool and an Arduino to talk to the STUSB4500 over I2C, the board can be configured to deliver from 5 to 20 VDC to whatever device you connect to it. The chip is even capable of storing three seperate Power Delivery Output (PDO) configurations at once, so you can give it multiple voltage and current ranges to try and negotiate for.

In the past we’ve seen a somewhat similar project that used USB-PD to charge lithium polymer batteries. It certainly isn’t happening overnight, but it looks like we’re finally starting to see some real movement towards making USB-C the standard.

Hacking The IKEA TRÅDFRI LED Power Supply

Just because something is being actively documented and tampered with by enthusiastic hackers doesn’t mean the information is handily centralized. There can be a lot of value in gathering disparate resources in one place, and that’s exactly what [Trammell Hudson] has done with his resource page for hacking the IKEA TRÅDFRI LED power supply with wireless interface. Schematic teardown, custom firmware images, it’s all there in one convenient spot.

Back in 2017, the IKEA TRÅDFRI hacking scene was centered around the LED light bulbs but as the group of products expanded, the rest of the offerings have also gotten some attention.

Why bother tampering with these units? One reason is to add features, but another is to make them communicate over your own MQTT network. And MQTT is the reason you are only a Raspberry Pi and a trip to IKEA away from the beginnings of a smart home that is under no one’s control or influence but your own.

Atomic Pi Gets A 3D-Printed Mac Makeover

The Atomic Pi is a pretty impressive piece of kit for the price, but it’s not exactly a turn-key kind of product. Even to a greater extent than what you might normally expect with a “dev” board like this, the user is responsible for putting together the rest of the pieces required to actually utilize it. But with this design by [Renri Nakano], you can turn the Atomic Pi into something that’s dangerously close to being a practical computer, and a trendy one at that.

Inspired by the 2019 Apple Mac Pro “Cheese Grater”, this 3D printable enclosure for the Atomic Pi is equal parts form and function. It integrates the necessary power supply to get things up and running without the need for the official breakout board or power module, which is good, since at the time of this writing they don’t seem to be available anyway. Plus it has a cool looking power button, so that’s got to count for something.

There’s also an integrated USB hub to give the Atomic Pi a bit more expandability, and a short HDMI extension cable that puts a video port on the back of the case. [Renri] even thought to leave an opening so you could run the wires for your wireless antennas.

At this point, we’ve seen several projects that mimic the unique case design of the 2019 Mac Pro. The level commitment ranges from recreating the design in CAD and milling it out of aluminum to just sticking a Raspberry Pi inside of a literal cheese grater from the kitchen. Naturally we enjoy a well executed Internet meme as much as the next hacker, but all the same, we were glad to see [Renri] put in the effort to make sure this case was more than just a pretty face.

[Thanks to baldpower for the tip.]

Switching Over To SMPS For Efficiency

[Hesam Moshiri] has built a variable switch-mode power supply over on When prototyping a new circuit, often the goal is to get a proof-of-concept working as soon as possible to iron out all of the bugs it might have. The power supply can easily be an afterthought, and for smaller projects we might just reach for an adjustable LM317 voltage regulator to dial in the correct voltage and then move on with the meat of the project. These linear regulators are incredibly inefficient though, so if you find yourself prototyping with one of these often enough, it might be worthwhile to switch to something better.

While it’s easy to simply buy a switch-mode power supply (SMPS) that has everything you need, and rated for 90% or higher efficiency at the same time, getting one with an adjustable output isn’t as easy. This one is based on the relatively popular LM2576-Adj chip which handles the switching frequency part of the circuit automatically. You will also need some large capacitors, an inductor (one of the disadvantages of an SMPS circuit) and a small potentiometer to use as the feedback control for the LM2576. This special pin allows the output voltage of the SMPS to be precisely controlled.

Granted, this project might not be breaking any new grounds, but if you’ve never given serious thought to your small breadboard circuit power supplies, it’s definitely worth looking into. An improvement from a linear regulator’s 30% efficiency to 90% efficiency from an SMPS will not only save you a ton of energy but also solve a lot of heat dissipation problems. If you don’t want to build a switch-mode supply 100% from scratch, though, it might also be possible to modify an existing one to suit your needs as well.

Adding Bluetooth Control To A Benchtop Power Supply

In 2019, it’s possible to kit out a lab with all the essentials at an even cheaper price than it has ever been. The DPS3005 is one such example of low-cost equipment – a variable power supply available for less than $50 with a good set of features. [Markel Robregado] wanted a little more functionality, however, and got down to work.

The crux of [Markel]’s project is improved connectivity. A Texas Instruments CC2640R2F Launchpad is employed to run the show, with its Bluetooth Low Energy capability coming in handy. A custom smartphone app communicates with the Launchpad, which then communicates with the power supply over its Serial Modbus interface. Through the app, [Markel] can set the voltage and current limit on the power supply, as well as switch it on and off. This could prove useful, particularly for remote triggering in the case of working with dangerous projects. Sometimes it pays to take cover, after all.

We’ve seen power supplies modified before; this pot mod for higher precision is a particular treat. If you’ve hacked your bench hardware for better performance, let us know. Video after the break.

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