Rare Arcade Game Teardown And Mods

September 9, 2023 by Al Williams 7 Comments

[Video Game Esoterica] loves a 1990s video game called Operation Tiger. Apparently, there are only a few of these known to exist in 2023, and he managed to find one of them. Well, it is really just a module so he has to figure out how to give it enough input and output to be actually playable. You can see several videos of his work with the Taito game below.

The board has a lot of ICs and a Power PC to handle the 3D graphics. The graphics seem clunky today, but they were impressive for the time. According to the video, the CPU board was only used for this game. The ROM that holds the software is separate with a mix of mask-programmed memory and EPROMs.

The machine is meant to live in an arcade box. So wiring things like coin selectors, video, speakers, and controllers is a non-trivial exercise. The wiring paid off, though, as the board started up but with no buttons, it wasn’t able to start in the first video. The controls go through a 60-pin connector and he tackles that project in part two.

The next step is to actually update the game software, which is hard but possible. Of course, you can run many of these old games with MAME or, if you prefer, use it to score that primo engineering workstation you used to covet.

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Agreeing By Disagreeing

September 9, 2023 by Elliot Williams 35 Comments

While we were working on the podcast this week, Al Williams and I got into a debate about the utility of logic analyzers. (It’s Hackaday, after all.) He said they’re almost useless these days, and I maintained that they’re more useful than ever. When we got down to it, however, we were actually completely in agreement – it turns out that when we said “logic analyzer” we each had different machines, and use cases, in mind.

Al has a serious engineering background and a long career in his pocket. When he says “logic analyzer”, he’s thinking of a beast with a million probes that you could hook up to each and every data and address line in what would now be called a “retrocomputer”, giving you this god-like perspective on the entire system state. (Sounds yummy!) But now that modern CPUs have 64-bits, everything’s high-speed serial, and they’re all deeply integrated on the same chip anyway, such a monster machine is nearly useless.

Meanwhile, I’m a self-taught hacker type. When I say “logic analyzer”, I’m thinking maybe 8 or 16 signals, and I’m thinking of debugging the communications between a microcontroller, an IMU, or maybe a QSPI flash chip. Heck, sometimes I’ll even break out a couple pins on the micro for state. And with the proliferation of easy and cheap modules, plus the need to debug and reverse commodity electronics, these logic analyzers have never been more useful.

So in the end, it was a simple misunderstanding – a result of our different backgrounds. His logic analyzers were extinct or out of my price range, and totally off my radar. And he thinks of my logic analyzer as a “simple serial analyzer”. (Ouch! But since when are 8 signals “serial”?)

And in the end, we both absolutely agreed on the fact that great open-source software has made the modern logic analyzers as useful as they are, and the lack thereof is also partially responsible for the demise of the old beasts. Well, that and he needs a lab cart then to carry around what I can slip in my pocket today. Take that!

A ceiling-mounted model of the Solar System

Ceiling-Mounted Orrery Is An Excercise In Simplicity

September 9, 2023 by Robin Kearey 29 Comments

Ever since humans figured out that planets move along predetermined paths in the heavens, they have tried to make models that can accurately predict their motion. Watchmakers and astronomers worked together to create orreries: mechanical contraptions that illustrate the positions of all planets and the way they move over time through complex gear systems. [Illusionmanager] continues the orrery tradition but uses a different approach: he built a beautiful ceiling-mounted model of our Solar System without a gearing system.

The mechanism that makes his Solar System tick is deceptively simple. All planets can move freely along their orbit’s axis except Mercury, which is moved along its orbit by a motor hidden inside the Sun. Once Mercury has completed a full revolution, a pin attached to its arm will begin pushing Venus along with it. After Venus has completed a full circle, its own pin will pick up Earth, and so on all the way to Neptune. Neptune is then advanced to its correct location as reported by NASA, after which Mercury’s motion is reversed and the whole procedure is repeated in the opposite direction to position Uranus.

Cycling through the entire Solar System in this way takes a long time, which is why the planets’ positions are only updated once a day at midnight. An ESP32, also hidden inside the Sun, connects to the internet to retrieve the correct positions for the day and drives the motor. The planet models, sourced from a museum shop, are hanging from thin aluminium tubes attached to wooden mounts made with a desktop CNC machine.

[Illusionmanager] made a detailed Instructables page showing the process of making a miniature version of the mechanism using just laser-cut wooden parts, as an update to a version we featured earlier. We really like the simplicity of this design, which stands in stark contrast to the huge gear trains used in more traditional orreries.

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Large Format Photos Without The Large Price Tag

September 9, 2023 by Jenny List 37 Comments

There’s a good reason that the go-to format for most film photographers is 35 mm, in that it provides a mix of convenience and cost. Shooting huge large-format negatives in the style of a 19th-century photographer can return astounding pictures with detail and lens effects unavailable on relatively tiny cameras, but it’s hardly the most convenient or cheapest medium. [Amos Chapple] may have a way to cut those costs though, by using a digital camera to capture the image projected by the camera onto a screen where the film would otherwise be.

He’s following in the footsteps of a Ukrainian photographer who tried the same technique photographing the projected image from the lens side, but that approach gave disappointing results due to the offset angle. Instead he’s placing the camera behind a translucent screen, having his DSLR behind a sheet of waxed paper held at the focal plane.

The results are we’d have to say, stunning. The old Soviet Ukrainian camera he’s using is something of a beast, but his photos of dancers at a folk festival have that other-worldly look to them which might well have something form the 1890s about it. We like it a lot and perhaps it’s tempting to fashion a poor-mans version using a cardboard box, and try for ourselves. Long-time readers will know it’s not the only attempt to digitize a large format camera we’ve seen.

The motherboard of a Mattel Aquarius, with a small daughterboard mounted on top

Adding Composite Video To The Mattel Aquarius

September 8, 2023 by Robin Kearey 14 Comments

In the home computer market of the 1980s, there were several winners that are still household names four decades later: the Commodore 64, the Apple II and the Sinclair Spectrum, to name a few. But where there are winners, there are bound to be losers as well – the Mattel Aquarius being a good example. A price war between the bigger players, combined with a rather poor hardware design, meant that the Aquarius was discontinued just a few months after its introduction in 1983. However, this makes it exactly the type of obscure machine that [Leaded Solder] likes to tinker with, so he was happy to finally get his hands on a neat specimen listed on eBay. He wrote an interesting blog post detailing his efforts to connect this old beast to a modern TV.

The main issue with the Aquarius is that it only has an RF video output, which results in a rather poor rendition of its already very limited graphics capabilities. Luckily, there is a fix available in the form of a composite A/V adapter that’s an almost plug-and-play upgrade. The only thing you need to do, as [Leaded Solder] illustrates in his blog post, is open up the computer, desolder the RF modulator and solder the A/V adapter in its place. Getting to that point was a bit tricky due to heavy EMI shields that were fixed in place with lots of solder, requiring liberal use of a desoldering iron. Continue reading “Adding Composite Video To The Mattel Aquarius” →

Linux Fu: Build A Better Ls

September 8, 2023 by Al Williams 27 Comments

Ask someone to name all the things they can find in a room. Only a few will mention air. Ask a Linux command line user about programs they use and they may well forget to mention ls. Like air, it is seemingly invisible since it is so everpresent. But is it the best it can be? Sure, you can use environment variables and aliases to make it work a little nicer, but, in fact, it is much the same ls we have used for decades. But there have always been moves to make better ls programs. One of them, exa, was recently deprecated in favor of one of its forks, eza.

One thing we liked about eza is that it is a single file. No strange installation. No multiple files to coordinate. Put it on your path, and you are done. So installation is easy, but why should you install it?

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A rotary subwoofer made out of a speaker coil, a medium-size fan an a grey wooden box to stand on.

Tear Apart Your House For $200 With This Rotary Subwoofer

September 8, 2023 by Julian Scheffers 44 Comments

Many movies and songs use a lot of of bass to make it feel more real to the viewer or listener. Because of this, subwoofers are common in high-quality audio setups, often costing a substantial part of the budget. [Daniel Fajkis] takes the subwoofer to it’s logical extreme by building a rotary subwoofer on a $200 budget.

The principle of a rotary subwoofer is that a normal subwoofer physically moves the air, and so does a fan. If you could make a fan oscillate the air instead of only pushing it, you could turn it into such a subwoofer, which is exactly what [Daniel] did. [Daniel] mounts a large electric motor on the case of an ex-subwoofer to spin the fan. Then, he uses the rotor linkage of a model helicopter and a modified subwoofer speaker to pitch the fan blades, spinning around to create a truly impressive gust of air oscillating at as low as 1 Hz.

The video, after the break, is well made with some good humor, including the legendary quote: “It’s gonna tear apart my household, there’s no way we’re surviving this one.”
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