Emulating A Forgotten UNIX Box

December 20, 2017 by Brian Benchoff 24 Comments

The AT&T 3B2 series of computers are historically significant, being the main porting platform for System V Release 3 UNIX. Unfortunately, the documentation for these computers has been nearly lost to the sands of time. They are, however, architecturally interesting machines, and [Seth Morabito] has been working for some time on reverse engineering them. Now, [Seth] is calling it: his AT&T 3B2/400 emulator is almost complete, resurrecting an ancient machine from the dead by studying UNIX source code.

The architecture of this computer is unlike anything you’ve seen before, but well-suited to a UNIX machine. The chipset is built around the WE32100 manufactured by Western Electric, and includes a WE32101 MMU for all the fancy memory-mapped I/O. The implementation of this computer is fairly complex, with oodles of glue logic, over a dozen PALs, and various support chips for a PLL and DRAM controllers. This is computer architecture the way it was intended: inscrutable, baroque, and with a lot of fancy custom chips.

The emulator for this system is a bit simpler: you can just download and run it with simh. This emulator simulates 1, 2, or 4MB of system memory, one 720KB floppy diskette, and either one or two 30MB, 72MB, or 161MB MFM hard disk drives. Not everything is implemented so far — [Seth] is still working on an 8-port serial card and a network card — but this is a minimum viable system for developing and analyzing the history of UNIX.

16-Cylinder Stirling Engine Gets A Tune Up

December 20, 2017 by Dan Maloney 33 Comments

Tiny catapults, kinetic sculptures, a Newton’s Cradle — all kinds of nifty toys can adorn the desk of the executive in your life. On the high end of the scale, a 16-cylinder butane-powered Stirling engine makes a nice statement, but when it comes equipped with a propeller that looks ready for finger-chopping, some mods might be in order before bestowing the gift.

We don’t knock [JohnnyQ90] for buying a rotary Stirling engine from one of the usual sources rather than building, of course. With his micro Tesla turbine and various nitro-powered tools, he’s proven that he has the machining chops to scratch-build one of these engines. And it wasn’t just the digit dicing potential of the OEM engine that inspired him. There was a little too much slop in the bearings for his liking, so he machined a new bearing block and shaft extension. With a 3D-printed shroud, a small computer fan, and snappy brass nose cone, the engine started looking more like a small jet engine. And the addition of a pulley and a small generator gave the engine something interesting to do. What’s more, the increased airflow over the cold end of the engine boosted performance.

Need the basics of Stirling engines? Here’s a quick look at the 200-year history of these remarkable devices.

Continue reading “16-Cylinder Stirling Engine Gets A Tune Up” →

Stromberg Carlson Charactron Tube

December 19, 2017 by Al Williams 21 Comments

Flat panel TVs have spoiled us. It used to be that a big display took up a lot of room on your desk or living room because of the depth of the CRT’s electron gun. We wonder what the designers of the charactron would think if they could see our big flat screens today. Never heard of a charactron? Check out [uniservo’s] video of one of these old character display tubes.

You might think the device is just a simple small CRT. However, it is much stranger than that. Inside the tube was a stencil that contained all the characters the device could display. A deflection coil would move an electron beam to light up a particular character. Then another coil would deflect the patterned electron beam to the desired space on the screen. In some cases, the entire set of stencils would get the beam and the first deflection coil would pick which character made it through an aperture. Either way, the tube was not just a display, but a character generator.

Continue reading “Stromberg Carlson Charactron Tube” →

Cryptanalyse Your Air Con

December 17, 2017 by Lewin Day 19 Comments

Infrared remote controls are simple and ubiquitous. Emulating them with the aid of a microcontroller is a common project that hackers use to control equipment as diverse as televisions, cable boxes, and home stereos. Some air conditioners can be a little more complicated, however, but [Ken]’s here to help.

The root of the problem is that the air conditioner remote was using a non-obvious checksum to verify if commands received were valid. To determine the function generating the checksum, [Ken] decided to bust out the tools of differential cryptanalysis. This involves carefully varying the input to a cryptographic function and comparing it to the differences in the output.

With 35 signals collected from the remote, a program was written to find input data that varied by just one bit. The checksum outputs were then compared to eventually put together the checksum function.

[Ken] notes that the function may not be 100% accurate, as they’re only using a limited sample of data in which not all the bytes change significantly. However, it shows that a methodical approach is valuable when approaching such projects.

Thirsty for more checksum-busting action? Check out this hacked weather station.

Reverse Engineering The Nintendo Wavebird

December 14, 2017 by Tom Nardi 21 Comments

Readers who were firmly on Team Nintendo in the early 2000’s or so can tell you that there was no accessory cooler for the Nintendo GameCube than the WaveBird. Previous attempts at wireless game controllers had generally either been sketchy third-party accessories or based around IR, and in both cases the end result was that the thing barely worked. The WaveBird on the other hand was not only an official product by Nintendo, but used 2.4 GHz to communicate with the system. Some concessions had to be made with the WaveBird; it lacked rumble, was a bit heavier than the stock controllers, and required a receiver “dongle”, but on the whole the WaveBird represented the shape of things to come for game controllers.

Finding the center frequency for the WaveBird

Given the immense popularity of the WaveBird, [Sam Edwards] was somewhat surprised to find very little information on how the controller actually worked. Looking for a project he could use his HackRF on, [Sam] decided to see if he could figure out how his beloved WaveBird communicated with the GameCube. This moment of curiosity on his part spawned an awesome 8 part series of guides that show the step by step process he used to unlock the wireless protocol of this venerable controller.

Even if you’ve never seen a GameCube or its somewhat pudgy wireless controller, you’re going to want to read though the incredible amount of information [Sam] has compiled in his GitHub repository for this project.

Starting with defining what a signal is to begin with, [Sam] walks the reader though Fourier transforms, the different types of modulations, decoding packets, and making sense of error correction. In the end, [Sam] presents a final summation of the wireless protocol, as well as a simple Python tool that let’s the HackRF impersonate a WaveBird and send button presses and stick inputs to an unmodified GameCube.

This amount of work is usually reserved for those looking to create their own controllers from the ground up, so we appreciate the effort [Sam] has gone through to come up with something that can be used on stock hardware. His research could have very interesting applications in the world of “tool-assisted speedruns” or even automating mindless stat-grinding.

Old TV Lends Case To Retro Magic Mirror

December 12, 2017 by Dan Maloney 10 Comments

Remember the days when the television was the most important appliance in the house? On at dawn for the morning news and weather, and off when Johnny Carson said goodnight, it was the indispensable portal to the larger world. Broadcast TV may have relinquished its hold on the public mind in favor of smartphones, but an information portal built into an old TV might take you back to the old days.

It seems like [MisterM] has a little bit of a thing for the retro look. Witness the wallpaper in the video after the break for proof, as well as his Google-ized Radio Shack intercom project from a few months back. His current project should fit right in, based on an 8″ black-and-white TV from the 70s as it is. TVs were bulky back then to allow for the long neck of the CRT, so he decided to lop off the majority of the case and use just the bezel for his build. An 8″ Pimoroni display sits where the old tube once lived, and replicates the original 4:3 aspect ratio. With Chromium set up in kiosk mode, the family can quickly select from a variety of news and information “channels” using the original tuning knob, while parts from a salvaged mouse turns the volume control into a scroll wheel.

It’s a nice twist on the magic mirror concept, and a little different from the other retro-TV projects we’ve seen, like a retro gaming console or an old-time case for a smart TV.

Continue reading “Old TV Lends Case To Retro Magic Mirror” →

Driver Board Makes Nixie Projects Easier Than Ever

December 8, 2017 by Dan Maloney 13 Comments

We know, we know — yet another Nixie clock. But really, this one has a neat trick: an easy to use, feature packed driver for Nixies that makes good-looking projects a snap.

As cool as Nixies are — we’ll admit that to a certain degree, familiarity breeds contempt — they can be tricky to integrate. [dekuNukem] notes that aside from the high voltages, laying hands on vintage driver chips like the 7441 can be challenging and expensive. The problem was solved with about $3 worth of parts, including an STM32 microcontroller and some high-voltage transistors. The PCBs come in two flavors, one for the IN-12 and one for the IN-14, and connections for the SPI interface and both high- and low-voltage supplies are brought out to header pins. That makes the module easy to plug into a motherboard or riser card. The driver supports overdriving to accommodate poisoned cathodes, 127 brightness levels for smooth dimming, and a fully adjustable RBG backlight under the tube. See the boards in action in the video below, which features a nicely styled, high-accuracy clock.

From Nixie tachs to Nixie IoT clocks, [dekuNukem]’s boards should make creative Nixie projects even easier. But if you’re trying to drive a Nixie Darth Vader, you’re probably on your own.