TechyMagThings

When Ridge Racer hit the arcades in the early 1990s, it came in a few different versions. The last variant used three large CRTs to create a wraparound display for the player. Incredibly rare, it’s believed that only a single-digit number of machines remain in existence. [beaumotplage] has secured a remaining example, and been working to preserve this historical artifact.

The first mission when it comes to this machine was to dump the ROMs, which have thus far not been preserved in any major archive. With that done, [beaumotplage] worked to hack a version of MAME that could emulate the Three Monitor Version’s unique mode of operation. As it turns out, each screen is driven by its own arcade board, with the three boards linked via C139 serial links. To emulate this, the trick was simply to write some C139 linkup code and run three versions of MAME all at once, letting them communicate with each other as the original boards would have. It’s a little janky in operation right now, but it does work!

You can download the hacked version of MAME for three-monitor operation here, though note that this does not include the ROM dumps from the machine itself. We look forward to seeing if the hardware ends up getting a full restoration back to operational standard, too.

Overall, this work goes to show that arcade preservation and archival work sometimes requires getting deep into the nitty-gritty technical stuff.

Generally when a game console with an optical drive stops reading discs the first thing that people do is crank on the potentiometer that controls the power to the laser diode to ramp up its output. While this can be a necessary solution to eke out a bit more life out of a clearly dying laser diode, this can actually massively shorten the lifespan of a good diode that’s just held back by bad capacitors. This is demonstrated by [Skawo] with a fix on a GameCube that stopped reading discs.

While it’s absolutely true that laser diodes have a limited lifespan, so do the capacitors and other components in the system. Thus, after tearing down this Japanese GameCube, [Skawo] accesses the optical PCB for some delicate plier-based capacitor surgery. One can absolutely question such violence, as well as the replacement mix of MLCC ceramics and a stray THT electrolytic capacitor, but the results after reassembly are obvious.

Without having to adjust the laser diode’s potentiometer, the game console now happily reads the game disc while the laser diode breathes a sigh of relief. Although all GameCube consoles will face the inevitable demise of their optical drives – barring a replacement optical pickup solution appearing – with this capacitor replacement solution it’s at least possible to stave off that undesirable time for a bit longer.

Those who have worked on a hobby operating system for x86 will have interacted with its rather complex and confusing interrupt model. [Evalyn] shows us why and how to use Flexible Return and Event Delivery (FRED), a new standard by the x86 Ecosystem Advisory Group.

Of course, it would be silly to omit the fact that Linux received patches first. But that isn’t the interesting part; after all, Linux is often the first place to have support for this kind of thing. No, what’s interesting is [Evalyn]’s implementation, to our knowledge among — if not the first — non-Linux operating system to support it.

To know why we should switch to FRED, we must first understand what it replaces. The Interrupt Descriptor Table (IDT) tells the CPU what code to run when certain interrupts or faults happen. The big problem that the IDT has is inconsistency, most egregiously the fact that the stack layout depends on which interrupt happened. To solve the issues with the IDT, FRED was created.

[Evalyn] shows us the process, starting at the documentation, then finding an emulator capable of it and culminating in a demo where DOOM runs in EvalynOS with FRED enabled.

Pentium II die shot. Martijn Boer, Public domain.

Although modern-day silvered glass mirrors have pretty much destroyed the market for bronze mirrors, these highly polished pieces of metal once were the pinnacle of mirror technology. Due to the laborious process required these mirrors saw use essentially only by the affluent. That said, how hard would it be to make a bronze mirror today with all of the modern technologies that even a hobbyist can acquire for their shed? Cue [Lundgren Bronze Studios] giving it a shot, starting by casting something flat-ish to start polishing.

Just getting that initial shape to start polishing is a chore, with hammering out the shape possibly being also a viable method. When casting metal it’s tricky to avoid having air bubbles and other defects forming, though using a sand mold seems to help a lot.

After you have the rough shape, polishing using power tools seems like cheating, but as you can see in the video even going from 50 to 8000 grit with a rotating disc left countless scratches. Amusingly, hand sanding did a much better job of removing the worst scratches, following which a polishing compound helped to bring out that literal mirror finish.

A quick glance at the Wikipedia entry for bronze mirrors shows that a tin-bronze alloy like speculum metal was used for thousands of years as it was much easier to polish to a good mirror finish. The metallurgy of what may seem like just a vanity item clearly goes deeper than just polishing up a metal surface.

Cooking food with fire is arguably the technology that propelled humans to become the dominant species on Earth. It’s pretty straightforward to achieve, just requiring a fuel source, a supply of oxygen from the air, and a way to initiate the reaction; then it self-sustains. You wouldn’t think there’s much to improve, but what about cooking with plasma? [Jay] from the plasma channel is no stranger here, and he thinks that there may be something in this idea, certainly enough to actually build something.

Now, let’s be straight with you, this isn’t a new concept, and you can buy a plasma-based cooking appliance right now. But they are all AC-powered devices. What if you want to go camping? [Jay] attempts (and succeeds) in building a portable, rechargeable 600W plasma cooking device that can actually cook food, but it was not all plain sailing.

The existing off-the-shelf ZVS driver modules available were a bit weak and unreliable, and the required flyback coils were hard to find with the right specs, so he needed to get down to work building custom parts. First off, the coils. Custom formers were resin-printed and machine-wound with 4000 turns of fine wire, and then resin-sealed into the former. [Jay] takes care to explain that it is crucial to get all the air out of the windings, or else local flashover breakdown will occur and wreck the coil in a short time. We reckon the resulting coils look amazing in their own right!

Next, the ZVS drivers on hand had low-quality capacitors (well, not enough capacitance anyway) and cheap driver transistors, so both were upgraded. The initial plan was to have four driver/coil pairs, each driving a single pair of electrodes, with a common ground ring connecting them all. It turns out this was a terrible idea: the drivers were not synchronised, so they were pulling on each other, causing catastrophic damage to the PCBs in a very short time. The solution was more complicated wiring, to give each coil secondary output a dedicated electrode pair, so there was no direct electrical connection between neighbouring coils and no coupling between them. A clever electrode arrangement meant that a pan would sit on top of a ring of electrodes, causing plasma discharges to jump directly to the pan, thereby concentrating localised heating there. We were wondering how this new direct connection (the pan is now a common connection!) didn’t also cause backfeeding and kill the ZVS drivers again, but it didn’t seem to happen.

Anyway, [Jay] demonstrates what is possibly the world’s first rechargeable, portable plasma cooker capable of making breakfast. Which we think is very important in its own right, however, we would like a plasma-based solution to making toast next, perhaps a plasma knife that cooks the bread as you slice it?

If this plasma cooking lark rings a bell, yes, we did touch upon this way back in 2017. And whilst not strictly plasma cooking, you can make an amazing microwave plasma in this ridiculously upgraded appliance. Definitely do not try that one at home.

That boiling water is a contentious topic of discussion is clear, but what about hot air? When you take a 12 VDC, 280 Watt-rated air fryer and pit it against a bog-standard 240 VAC, 1400 Watt unit, which one would you want to use when you’re doing some camping or other exciting off-the-grid opportunities? Unlike with boiling water the physics aren’t as clear-cut here, so [Cahn] did some testing to figure out exactly what the efficiency numbers look like

Since air fryers rely on the transfer of thermal energy from the resistive heating element into the food, any thermal energy that’s not immediately transferred is effectively wasted. This, combined with the relatively low power rating and thus much higher time demand of the low-voltage air fryer is enough to set one’s expectations pretty low.

As scientific test samples chicken nuggets were used with the test, following a preheating period for the 12 VDC unit. Both units managed to hit a safe temperature inside the nuggets after 20 minutes, thus successfully staving off food poisoning, but the browning with the 240 VAC air fryer was much better.

As for the efficiency, the 12 VDC unit required 150 Wh for 20 minutes plus the 10 minutes of preheating, with 45 minutes total at 225 Watt to get proper browning. Meanwhile the 240 VAC unit burned through 250 Wh in 20 minutes, with no pre-heating, though only 230 Wh with no inverter losses included. As a final test, the 12 VDC unit was run at 400 Watt using 14.6 VDC input, which did indeed get it up to temperature much faster.

Thus both are equivalent, just with the caveat that the low-voltage unit will take considerably more time to get the same result. This mirrors the results with boiling water, where most options mostly vary in how much time they require to get water up to a boiling temperature.

It’s fair to say that there are a lot of development board form factors for MCUs, with [Tech Dregs] over on yonder YouTube on the verge of adding another one to the pile, but not before he was having some serious thoughts on the implications of such a decision. Does this world really need another devboard with the ubiquitous 2.54 mm (0.1″) pitch pin headers, all so that it can perhaps be used in the same traditional 2.54 mm pitch breadboards?

The thought that [Tech Dregs] is playing with is to go for something more akin to the system-on-module  (SoM) approach that’s reminiscent of the Raspberry Pi compute module form factor. This means using a 1 mm pitch for the headers and castellated edges in case you want use it as an SMT part, while breaking out many more pins of the onboard ESP32 module in far less space.

Obviously, the main advantage of this approach is that much like with compute modules you can leave most of the tedious cheap stuff on a carrier board, while the expensive to manufacture components are on a self-contained module. Meanwhile with the much finer pitch on the SoM contacts it’d straddle the divide between a 2.54 mm breadboard-capable devboard and a fully custom PCB, while making any mistakes on the carrier board much cheaper to redo.

The counterpoint here is of course that something like an ESP32 module is already a module with a finer pitch, but if you need more than just what it offers, or you want to use an STM32 or RP MCU across boards it could make a lot of sense.

Having 1 mm pitch breadboards would honestly also be rather nifty, natch. That said, what are your thoughts on this matter?