Vintage Aircraft Controls Turned USB Button Box

July 25, 2020 by Tom Nardi 4 Comments

The Gables Engineering G-2789 audio selector panels aren’t good for much outside of the aircraft they were installed in, that is, until [MelkorsGreatestHits] replaced most of the internals with a Teensy 3.2. Now they are multi-functional USB input devices for…well, whatever it is you’d do with a bunch of toggle switches and momentary push buttons hanging off your computer.

With the Teensy going its best impression of a USB game controller, the host operating system has access to seven momentary buttons, twelve toggles, and one rotary axis for the volume knob.

Right now [MelkorsGreatestHits] says the code is set up so the computer sees a button press on each state change; in other words, the button assigned to the toggle switch will get “pressed” once when it goes up and again when it’s flicked back down. But of course that could be modified depending on what sort of software you wanted to interface the device with.

As we’ve seen with other pieces of vintage aircraft instrumentation, lighting on the G-2789 was provided by a series of incandescent bulbs that shine through the opaque front panel material. [MelkorsGreatestHits] replaced those lamps with white LEDs, but unfortunately the resulting light was a bit too harsh. As a quick fix, the LEDs received a few coats of yellow and orange paint until the light was more of an amber color. Using RGB LEDs would have been a nice touch, but you work with what you’ve got.

This isn’t the first time that [MelkorsGreatestHits] has turned an old aircraft cockpit module into a USB input device, and we’re certainly interested in seeing what the next project will look like. Though we’re perhaps more interested in finding out where all all these old school airplane parts are coming from…

Finding A Secret Message From A Gaming Legend

July 4, 2020 by Tom Nardi 6 Comments

Satoru Iwata is perhaps best remembered for leading Nintendo through the development of the DS and Wii, two wildly successful systems which undeniably helped bring gaming to a wider and more mainstream audience. But decades before becoming the company’s President in 2002, he got his start in the industry as a developer working on many early console and computer games. [Robin Harbron] recently decided to dig into one of the Iwata’s earliest projects, Star Battle for the VIC-20.

Finding the message was easy, if you knew were to look.

It’s been known for some time that Iwata, then just 22 years old, had hidden his name and a message in the game’s source code. But [Robin] wondered if there was more to the story. Looking at the text in memory, he noticed the lines were actually null-terminated. Realizing the message was likely intended to get printed on the screen at one point during the game’s development, he started hunting for a way to trigger the nearly 40 year old Easter Egg.

As it turns out, it’s hidden behind a single flag in the code. Just change it from 0 to 1, and the game will display Iwata’s long-hidden credit screen. That proved the message was originally intended to be visible to players, but it still didn’t explain how they were supposed to trigger it during normal game play.

That’s where things really get interesting. As [Robin] gives us a guided tour through Star Battle’s inner workings, he explains that Iwata originally intended the player to hit a special combination of keys to tick over the Easter Egg’s enable flag. All of the code is still there in the commercial release of the game, but it’s been disabled. As Iwata’s life was tragically cut short in 2015 due to complications from cancer, we’ll perhaps never know the reason he commented out the code in question before the game was released. But at least we can now finally see this hidden message from one of gaming’s true luminaries.

Last time we heard from [Robin], he’d uncovered a secret C64 program hidden on a vinyl record. With his track record so far, we can’t wait to see what he digs into next. Continue reading “Finding A Secret Message From A Gaming Legend” →

Dissecting A Mechanical Voltage Regulator

April 20, 2020 by Tom Nardi 55 Comments

When the fuel gauge of his 1975 Triumph Spitfire started going off the scale, the collected knowledge of the Internet indicated that [smellsofbikes] needed to replace a faulty voltage regulator behind the dash. For most people, that would be the end of the story. But he, like everyone who’s reading this right now, really wanted to see what the inside of a 45 year old voltage regulator looked like.

After prying open the metal case, he discovered that not only is the regulator mechanical in nature, but there’s even a tiny screw that allows you to adjust the output voltage. Luckily for us, not only is [smellsofbikes] curious enough to open it up, but he’s also got the tools and knowledge to explain how it works in the video after the break.

Put simply, the heart of the regulator is a bimetallic strip with a coil of wire wrapped around it. When power from the battery is passed through the coil it acts as a heater, which makes the strip move up and break the connection to the adjustable contact. With the connection broken and the heating coil off the strip rapidly cools, and in doing so returns to its original position and reconnects the heater; thus starting the process over again.

These rapid voltage pulses average out to around 10 VDC, though [smellsofbikes] notes that you can’t actually measure the output voltage of the regulator with a meter because it moves around too much to get any sort of accurate reading. He also mentions a unique quirk of this technology: due to the force of gravity acting on the bimetallic strip, the output of the regulator will actually change depending on its mounting orientation.

On the oscilloscope, [smellsofbikes] is able to show us what the output actually looks like. As you might expect, it looks like a mess to 21st century eyes. But these were simpler times, and it should go without saying there aren’t any sensitive electronics in a sports car from 1975. Interestingly, he says he’s now replaced the mechanical assembly with a modern regulator chip. Here’s hoping we’re around long enough to see if he gets another 50 years out of it.

Continue reading “Dissecting A Mechanical Voltage Regulator” →

’54 Motorcycle Saved By Electric Conversion

April 17, 2020 by Bryan Cockfield 29 Comments

While it’s nice to be able to fully restore something vintage to its original glory, this is not always possible. There might not be replacement parts available, the economics of restoring it may not make sense, or the damage to parts of it might be too severe. [onyxmember] aka [Minimember Customs] was in this position with an old ’54 Puch Allstate motorcycle frame that he found with no engine, rusty fuel tank, and some other problems, so he did the next best thing to a full restoration. He converted it to electric.

This build uses as much of the original motorcycle frame as possible and [onyxmember] made the choice not to weld anything extra to it. The fuel tank was cut open and as much rust was cleaned from it as possible to make room for the motor controller and other electronics. A hub motor was laced to the rear wheel, and a modern horn and headlight were retrofitted into the original headlight casing. Besides the switches, throttle, and voltmeter, everything else looks original except, of course, the enormous 72V battery hanging off the frame where the engine used to be.

At a power consumption of somewhere between three and five kilowatts, [onyxmember] reports that this bike likely gets somewhere in the range of 55 mph, although he can’t know for sure because it doesn’t have a speedometer. It’s the best use of an old motorcycle frame we can think of, and we also like the ratrod look, but you don’t necessarily need to modify a classic bike for this. A regular dirt bike frame will do just fine.

Continue reading “’54 Motorcycle Saved By Electric Conversion” →

Bus Sniffing Leads To New Display For Vintage Casio

March 8, 2020 by Tom Nardi 11 Comments

Despite his best efforts to repair the LCD on his Casio FX-702P, it soon became clear to [Andrew Menadue] that it was a dead-end. Rather than toss this relatively valuable device in the trash, he wondered if would be possible to replace the LCD with a more modern display. Knowing that reverse engineering the LCD panel itself would be quite a challenge, he decided instead to focus his efforts on decoding the communications between the calculator’s processor and display controller.

With his logic analyzer connected to the Casio’s four bit bus [Andrew] was able to capture a sequence of bytes during startup that looked promising, although it didn’t quite make sense at first. He had to reverse the order of each nibble, pair them back up into bytes, and then consult the FX-702P’s character map as the device doesn’t use ASCII. This allowed him to decode the message “READY”, and proved the concept was viable.

Of course a calculator with a logic analyzer permanently attached to it isn’t exactly ideal, so he started work on something a bit more compact. Armed with plenty of display controller data dumps, [Andrew] wrote some code for a STM32 “Blue Pill” ARM Cortex M3 microcontroller that would sniff and decode the data in near real-time. In the video after the break you can see there’s a slight delay between when he pushes a button and when the corresponding character comes up on the LCD below, but it’s certainly usable.

Unfortunately, the hardware he’s created for this hack is just slightly too large to fit inside the calculator proper. The new LCD is also nowhere near the size and shape that would be required to replace the original one. But none of that really matters. While [Andrew] says he could certainly make the electronics smaller, the goal was never to restore the calculator to like-new condition. Sometimes it’s more about the journey than the destination.

Continue reading “Bus Sniffing Leads To New Display For Vintage Casio” →

Foam Board, Old Electronics, And Imagination Make Movie Magic

December 31, 2019 by Dan Maloney 11 Comments

When it comes to building sets and props for movies and TV, it’s so easy to get science fiction wrong – particularly with low-budget productions. It must be tempting for the set department to fall back on the “get a bunch of stuff and paint it silver” model, which can make for a tedious experience for the technically savvy in the audience.

But low-budget does not necessarily mean low production values if the right people are involved. Take [Joel Hartlaub]’s recent work building sets for a crowdfunded sci-fi film called Infinitus. It’s a post-apocalyptic story that needed an underground bunker with a Fallout vibe to it, and [Joel] jumped at the chance to hack the sets together. Using mainly vintage electronic gear and foam insulation boards CNC-routed into convincing panels, he built nicely detailed control consoles for the bunker. A voice communicator was built from an old tube-type table radio case with some seven-segment displays, and the chassis of an old LCD projector made a convincing portable computer terminal. The nicest hack was for the control panel of the airlock door. That used an old TDD, or telecommunications device for the deaf. With a keyboard and a VFD display, it fit right into the feel of the set. But [Joel] went the extra mile to make it a practical piece, by recording the modulated tones from the acoustic coupler and playing them back, to make it look as if a message was coming in. The airlock door looks great too.

Like many hacks, it’s pretty impressive what you can accomplish with a deep junk pile and a little imagination. But if you’ve got a bigger budget and you need some computer displays created, we know just the person for the job.

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Peek Inside These Same-But-Different Power Supplies

December 28, 2019 by Donald Papp 5 Comments

When [Kerry Wong] found an Amrel PPS 35-2 Programmable Power Supply from the late 90s on eBay, he recognized it as the single-channel version of another unit he owned, the dual-channel Amrel PPS-2322. Naturally, he purchased it and did a compare and contrast of the two models.

From the outside, they look fairly different but weigh about the same. But the similarities on the inside make it quite clear that they share a common design. There are a few things that grab your eye and the 35-2 doesn’t seem quite as well thought out, with some components being soldered into awkward-looking places. Capacitors bristle like barnacles where they are soldered directly to a connector, and a blob of hot glue anchors two resistors that rise up out of the board like a couple of weeds.

The link above shows some high resolution side-by-side photos between the two models, and [Kerry] thoughtfully provides a link to the manual for the PPS series as well as a dump of the firmware (.zip) for the 35-2. A teardown video is embedded below.

Benchtop power supplies are important tools, but we’ve also seen how modern breadboard power supplies are remarkably full-featured.

Continue reading “Peek Inside These Same-But-Different Power Supplies” →