Coffee Table Model Railroad With All The Bells And Whistles (and Lights And Sirens)

December 22, 2017 by Dan Maloney 14 Comments

For some, the allure of a real, physical world that you create and control is overwhelming. Combine that with a love of trains, and you get the model railroad. Some are incredibly detailed, and it seems like the larger the layout the better. Not everyone has the real-estate to devote to such a hobby, though, and moving down to N-gauge railroads is often the key to scratching the model railroad itch in a confined space.

But [Chris Plumley]’s complete N-gauge model railroad in a coffee table takes the concept to a new and tiny level. The superlatives to describe this layout are many and begin with the coffee table itself, a free-form sculptural design intended to evoke the natural contours of a landscape. Removing the lid reveals an intricately detailed world that rises up on a lift. The mainline train and a two-station trolley line ply the imaginary world under full computer control, complete with sound effects and animated lighting. An LCD screen stands in for a drive-in movie theater — remember drive-ins? — and a house fire rages on, never to be quenched by the arriving fire engines. And as a bonus, the locomotive has a dash cam to provide an engineer’s eye view of the layout. The attention to detail is wonderful, but the kicker is that this layout has existed in one form or another for sixty years. Talk about persistence!

If you’re intrigued by combining the world of microcontrollers and model railroads, you should really check out this tutorial to get started.

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Can This Commodore 64 Be Saved?

December 21, 2017 by Al Williams 29 Comments

If you are a certain age, there’s a fair chance your first computer was a Commodore 64. These machines are antiques now, and [RetroManCave] received one from a friend’s loft in unknown condition. He’s made two out of three videos covering the machine, its history, and its internals. Assisting is Commodore 64 expert [Jan Beta] who apparently owned one way back when. You can see the first two videos, below.

The machine isn’t as old as you might think — it is the “newer” case style (circa 1987). [Jan] gives a great overview of the different motherboards you might encounter if you are lucky enough to come across one of these in a dumpster somewhere.

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Building A Supersized Game Boy Advance

December 21, 2017 by Tom Nardi 5 Comments

Unless you really look closely at the image above, you might not realize you aren’t looking at a normal Game Boy Advance; which is sort of the point. Even though it retains the looks of the iconic Nintendo handheld, this version built by [Akira] is supersized for adult hands. How big is it? To give you an idea, that screen is 5 inches, compared to the 2.9 inch screen the original sported.

Unlike most of the portable gaming hacks we’ve covered recently, this big-boy GBA isn’t powered by a Raspberry Pi. Internally it’s packing a genuine GBA motherboard, which has been wired into a portable screen originally intended for the PlayStation.

Though that may be understating things a bit, as getting the round PCB of the original screen into the rectangular shape of the GBA meant it had to be cut down and the traces recreated with jumper wires. The original CCFL backlight of the screen had to go in the name of battery life, and in its place is the backlight system pulled from a Nintendo DSi XL.

But where did [Akira] get a giant GBA case to begin with? No, it isn’t 3D printed. It’s actually a hard carrying case that was sold for the GBA. The carrying case obviously didn’t have a cartridge slot or openings for buttons, so those sections were grafted from a donor GBA case. So despite the system overall being so much bigger than the original, the D-Pad, face buttons, and cartridge slot on the back are at normal GBA scale.

The GBA XL is really a labor of love; browsing through the build log you can see that [Akira] actually started the project back in 2014, but it kept getting shelved until more research could be done on how to pack all the desired features into the final device.

While this may be the most historically accurate attempt at making a bigger Game Boy, it certainly isn’t the first. There seems to be a fascination with turning the quintessential pocket game system into something that’s quite the opposite.

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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.

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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.

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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.