Computer Space Flies Again

November 10, 2022 by Jonathan Bennett 11 Comments

[Sean] from Classic Arcade Repairs fixes classic arcade machines, and he got a request to repair a very special machine. It’s Computer Space, the first commercial arcade cabinet ever made, and loosely based on Spacewar! This grand-daddy of coin-op was a literal barn find, and was in pretty bad shape after sitting for years. All the parts appeared to be original, making them 50 years old. As you can imagine, that combination didn’t bode well for the health of the components. There’s a couple hours of footage here, but it’s invaluable troubleshooting advice, and very cool to see such an old machine being worked on.

Part one is the intro, and [Sean] started with an HP logic analyzer, just probing the many TTL chips on the board looking for floating or otherwise suspicious outputs. Figure out the obviously faulty chips and replace each with a socket and new chip. Just about every diode in the machine needed replacing.

Part two of the repair starts with a broken trace repair, and the discovery that all the ceramic capacitors on the boards were leaky. The interesting thing is that a multimeter tested those caps as having the correct capacitance, but a dedicated leak tester discovered the problem.

Part 3 shows the process of running the remaining chips through a logic tester, which found more problematic ICs. In some cases, a chip would only sometimes test as working. And strangely, one of the new, replacement chips turned out to have a problem. Though as a commenter pointed out, it could be a falling edge vs rising edge variation of the logic chips to blame. Or maybe the new chips were counterfeit. Hard to nail down.

Part 4 starts with a gotcha moment, where one of the first repairs to the board was a misstep. What appeared to be a damaged trace, was actually a factory modification (a bodge cut?). Then a lucky break really helped out, where only half of one of the 7476 chips was in use, and one of the chips on hand was only half working. Put the dead bit into the unused slot, and the machine really started to behave.

Part 5 is the victory lap, where all the components finally arrived, and everything starts working on the bench. How cool to see the old machine bleeping and blooping again.

Photo of the back of a slingbox appliance, with ports shown and arrows going to them describing what each of the ports does.

Slingbox Getting Bricked – You Have Less Than 24 Hours

November 8, 2022 by Arya Voronova 41 Comments

The Slingbox devices used to let you catch up with the programming on your TV when you weren’t near it, using your Internet-connected mobile device. As cable TV became less popular, their business model faded away, and in 2020, they scheduled a service shutdown for November 9th, 2022. If you own a Slingbox, it’s getting bricked tomorrow – for those reading this in EU, that’ll be today, even. Do you have a Slingbox? You might still be able to repurpose it, let’s say, for local media streaming – but only if you waste no time.

[Gerry Dubois] has been developing the “Slinger” software for the past few months, a small app you run locally that proxies commands and video for your Slingbox, thanks to reverse-engineering communications with Slingbox servers. However, it needs a “hardware password” alphanumeric string, that you need to get from the Slingbox service web interface – which is to be promptly shut down. If you think you might have a use for what’s essentially a network-connected analog/digital video capture card with decent hardware, the GitHub repo has a lively discussion tab for any questions you might have.

One one hand, Slingbox shouldn’t be bricking the devices in a way that requires you act fast – perhaps, releasing a final update that makes the device hacker-friendly, like O2 did with their Joggler appliance back in the day, publishing the hardware documentation, or at least setting up a service up that lets anyone retrieve their hardware password indefinitely. On the other hand, at least they gave us two years’ notice, something less than usual – the amount of time between bricking and an announcement can even be a negative number. For those of us stuck with no operational device, a hardware exploration might be in order – for instance, we’ve torn down the Sling Adapter and even ran simple custom code on it!

Cheap Scope Troubleshoots Commodore

November 8, 2022 by Al Williams 17 Comments

[Adrian] had a Commodore computer to fix and decided to see how his latest tiny portable scope would work. He paid $57 for the tiny little test instrument although the current price seems higher. It claims to have 120MHz bandwidth along with 500 megasamples per second. There are several versions with different claimed specs, but we did find a similar device for under $60. You can see the unboxing and how it worked in the video below.

Of course, these kinds of instruments often overstate their specs, and [Adrian] was also suspicious. One odd feature of the device is it can echo its output to an NTSC video output so you can send the screen to an external monitor.

Continue reading “Cheap Scope Troubleshoots Commodore” →

The SSD described, a green board with a ZIP connector, a controller chip and two out of four NAND chips populated. There's traces of flux on the chip, as it hasn't been washed after soldering yet.

ZIF HDDs Dying Out? Here’s An Open-Source 1.8″ SSD

October 30, 2022 by Arya Voronova 14 Comments

A lot of old technology runs on parts no longer produced – HDDs happen to be one such part, with IDE drives specifically being long out of vogue, and going extinct to natural causes. There’s substitutes, but quite a few of them are either wonky or require expensive storage medium. Now, [dosdude1] has turned his attention to 1.8 ZIF IDE SSDs – FFC-connected hard drives that are particularly rare and therefore expensive to replace, found in laptops like the Macbook Air 1,1 2008 model. Unsatisfied with substitutes, he’s designed an entire SSD from the ground up around an IDE SSD controller and NAND chips. Then, he made the design open-source and filmed an assembly video so that we can build our own. Take a look, we’ve put it below the break!

For an open-source design, there’s a respectable amount of work shared with us. He’s reverse-engineered some IDE SSDs based on the SM2236 controller to design the schematic, and put the full KiCad files on GitHub. In the video, he shows us how to assemble this SSD using only a hot air station and a soldering iron, talks about NAND matching and programming software intricacies, and shows the SSD working in the aforementioned Macbook Air. Certainly, assembly would have been faster and easier with a stencil, but the tools used work great for what’s a self-assembly tutorial!

Continue reading “ZIF HDDs Dying Out? Here’s An Open-Source 1.8″ SSD” →

A solar inverter that asks for a password on its display

Decompiling Software To Fix An Old Solar Inverter

October 20, 2022 by Robin Kearey 16 Comments

It’s a fact of life that electronic devices become obsolete after a few years. Sometimes this is because technology has moved on, but it can also happen that a perfectly functional device becomes near-useless simply because the original manufacturer no longer supports it. When [Buy It Fix It] found a pair of second-hand Power-One Aurora solar inverters, he ran into an issue for which he needed access to the service menu, which happened to be password-protected. The original manufacturer had ceased to exist, and the current owner of the brand name was unable to help, so [Buy It Fix It] had to resort to reverse engineering to find the password.

Thanks to the Wayback Machine over at the Internet Archive, [Buy It Fix It] was able to download the PC software bundle that originally came with the inverters. But in order to access all features, a password was required that could only be obtained by registering the unit with the manufacturer. That wasn’t going to happen, so [Buy It Fix It] fired up dnSpy, a decompiler and debugger for .NET programs. After a bit of searching he found the section that checked the password, and by simply copying that section into a new program he was able to make his own key generator.

With the service password now available, [Buy It Fix It] was able to set the inverter to the correct voltage setting and hook it up to his solar panels. Interestingly, the program code also had references to “PONG”, “Tetris” and “tiramisu” at various places; these turned out to be Easter eggs in the code, containing simple versions of those two games as well as a photo of the Italian dessert.

Inside the software archive was also another program that enabled the programming of low-level functions within the inverter, things that few users would ever need to touch. This program was not written in .NET but in C or something similar, so it required the use of x32dbg to look at the machine code. Again, this program was password-protected, but the master password was simply stored as the unencrypted string “91951” — the last five digits of the manufacturer’s old phone number.

The inverter was not actually working when [Buy It Fix It] first got it, and his repair video (also embedded below) is also well worth watching if you’re into power electronics repair. Hacking solar inverters to enable more features is often possible, but of course it’s much easier if the entire design is open source.

Continue reading “Decompiling Software To Fix An Old Solar Inverter” →

Analog Tank Driving Simulator Patrols A Tiny Physical Landscape

October 18, 2022 by Danie Conradie 30 Comments

How do you build a practical tank-driving simulator in the 1970s, when 3D computer-generated graphics are still just a fantasy of the future? If you’re a European tanker school, the solution is to use a large CNC machine to drive a camera around a miniature terrain model (German, translated). In the video after the break, [Tom Scott] takes it for a test drive.

The old computer was replaced with a Raspberry Pi — The original computer was replaced with a Raspberry Pi

Developed in France, the simulator provided a safer and more cost-effective way for teaching new trainees the basics of driving Centurion, Leopard 2, or Panzer 68 tanks. The trainee sits in a realistic “cockpit” mounted on a hydraulically-operated motion platform, with a TV screen in front of his face, which is connected to a camera mounted on a large gantry-style CNC platform.

The camera’s lens is mounted just above a pivoting metal foot which slides across the 12 m-long terrain model and sends its angle to the hydraulic system. It will even alter the tank’s handling based on its current position on the model to simulate different surfaces like dirt, snow, or asphalt.

The last of these systems remained in use until 2004 at the military training center in Thun, Switzerland, before being saved by the Swiss Military Museum from being scrapped. The original 70s computer, electronics, and hydraulics finally gave out, so the museum undertook a complete refurbishment of the system to return it to working order for museum visitors. It was kept as original as possible, but parts for the original computer could not be found, so it was replaced with a Raspberry Pi and custom interface board.

Over three decades, these simulators probably trained a few thousand tank drivers, and even with limited technology did an excellent job of preparing trainees for the real thing. Besides providing training for operators, drivers and pilots, simulators are also just plain fun. We’ve seen some impressive home built simulator including a A-10 Warthog, an F-15 sim built from an actual wreckage, and even a starship’s bridge.

Continue reading “Analog Tank Driving Simulator Patrols A Tiny Physical Landscape” →

An exploded diagram of the spot welder. Shown are the capacitor bank, trigger, 12 V relay, DC power input, power out, step up converter, voltmeter, industrial SCR module, and capacitor bank.

Hackaday Prize 2022: A Not-So-Smart Spot Welder

October 17, 2022 by Navarre Bartz 5 Comments

DIY spot welders often use high-powered components that can be a bit frightening, given the potential for dangerous malfunctions. [Wojciech “Adalbert” J.] designed his capacitive discharge spot welder to be safe, easy to build, and forego the microcontroller.

Many projects work great with just a single Li-ion cell, but when you need more power, you’ve got to start connecting more cells together into a battery. [Wojciech]’s spot welder is designed to be just powerful enough to weld nickel tabs onto a cell without any overkill. The capacitor bank uses nineteen Nichicon UBY 7500uF/35V capacitors, all wired in parallel using solder wick saturated with solder. They sit atop on a perfboard with metallicized holes to carry the high current.

[Wojciech] has detailed every step of building the welder, including changes to the off-the-shelf relay board and adding a potentiometer to the step-up converter board. The level of detail makes this seem like a good starting place if you’re hoping to hop into the world of DIY spot welders. Safe is always a relative term when dealing with high powered devices, so be careful if you do attempt this build!

DIY spot welders have graced these digital pages many times, including this one built with safety in mind, and this other one that was decidedly not.