8-Tracks Are Back? They Are In My House

June 10, 2024 by 53 Comments

What was the worst thing about the 70s? Some might say the oil crisis, inflation, or even disco. Others might tell you it was 8-track tapes, no matter what was on them. I’ve heard that the side of the road was littered with dead 8-tracks. But for a while, they were the only practical way to have music in the car that didn’t come from the AM/FM radio.

If you know me at all, you know that I can’t live without music. I’m always trying to expand my collection by any means necessary, and that includes any format I can play at home. Until recently, that list included vinyl, cassettes, mini-discs, and CDs. I had an 8-track player about 20 years ago — a portable Toyo that stopped working or something. Since then, I’ve wanted another one so I can collect tapes again. Only this time around, I’m trying to do it right by cleaning and restoring them instead of just shoving them in the player willy-nilly.

Update: I Found a Player

A small 8-track player and equally small speakers, plus a stack of VHS tapes.
I have since cleaned it.

A couple of weeks ago, I was at an estate sale and I found a little stereo component player and speakers. There was no receiver in sight. I tested the player with the speakers and bought them for $15 total because it was 75% off day and they were overpriced originally. While I was still at the sale, I hooked it up to the little speakers and made sure it played and changed programs.

Well, I got it home and it no longer made sound or changed programs. I thought about the play head inside and how dirty it must be, based on the smoker residue on the front plate of the player. Sure enough, I blackened a few Q-tips and it started playing sweet tunes again. This is when I figured out it wouldn’t change programs anymore.

I found I couldn’t get very far into the player, but I was able to squirt some contact cleaner into the program selector switch. After many more desperate button presses, it finally started changing programs again. Hooray!

I feel I got lucky. If you want to read about an 8-track player teardown, check out Jenny List’s awesome article. Continue reading “8-Tracks Are Back? They Are In My House” →

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Hackaday Links: June 9, 2024

June 9, 2024 by 32 Comments

We’ve been harping a lot lately about the effort by carmakers to kill off AM radio, ostensibly because making EVs that don’t emit enough electromagnetic interference to swamp broadcast signals is a practical impossibility. In the US, push-back from lawmakers — no doubt spurred by radio industry lobbyists — has put the brakes on the move a bit, on the understandable grounds that an entire emergency communication system largely centered around AM radio has been in place for the last seven decades or so. Not so in Japan, though, as thirteen of the nation’s 47 broadcasters have voluntarily shut down their AM transmitters in what’s billed as an “impact study” by the Ministry of Internal Affairs and Communications. The request for the study actually came from the broadcasters, with one being quoted in a hearing on the matter as “hop[ing] that AM broadcasting will be promptly discontinued.” So the writing is apparently on the wall for AM radio in Japan.

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Comparing X86 And 68000 In An FPGA

June 7, 2024 by 15 Comments

[Michael Kohn] started programming on the Motorola 68000 architecture and then, for work reasons, moved over to the Intel x86 and was not exactly pleased by the latter chip’s perceived shortcomings. In the ’80s, the 68000 was a very popular chip, powering everything from personal computers to arcade machines, and looking at its architecture and ease of programming, you can see why this was.

Fast-forward a few years, and [Michael] decided to implement both cores in an FPGA to compare real applications, you know, for science. As an extra bonus, he also compares the performance of a minimal RISC-V implementation on the same hardware, taken from an earlier RISC-V project (which you should also check out !)

Utilizing their ‘Java Grinder’ application (also pretty awesome, especially the retro console support), a simple Mandelbrot fractal generator was used as a non-trivial workload to produce binaries for each architecture, and the result was timed. Unsurprisingly, for CISC architectures, the 68000 and x86 code sizes were practically identical and significantly smaller than the equivalent RISC-V. Still, looking at the execution times, the 68000 beat the x86 hands down, with the newer RISC-V speeding along to take pole position. [Michael] admits that these implementations are minimal, with no pipelining, so they could be sped up a little.

Also, it’s not a totally fair race. As you’ll note from the RISC-V implementation, there was a custom RISC-V instruction implemented to perform the Mandelbrot generator’s iterator. This computes the complex operation Z = Z2 + C, which, as fellow fractal nerds will know, is where a Mandelbrot generator spends nearly all the compute time. We suspect that’s the real reason RISC-V came out on top.

If actual hardware is more your cup of tea, you could build a minimal 68k system pretty easily, provided you can find the chips. The current ubiquitous x86 architecture, as odd as it started out, is here to stay for the foreseeable future, so you’d just better get comfortable with it!

Continue reading “Comparing X86 And 68000 In An FPGA” →

This Week In Security: Recall, Modem Mysteries, And Flipping Pages

June 7, 2024 by 6 Comments

Microsoft is racing to get into the AI game as part of Windows 11 on ARM, calling it Copilot+. It’s an odd decision, but clearly aimed at competing with the Apple M series of MacBooks. Our focus of interest today is Recall, a Copilot+ feature that not only has some security problems, but also triggers a sort of visceral response from regular people: My computer is spying on me? Eww.

Yes, it really sort of is. Recall is a scheme to take screen shots of the computer display every few seconds, run them through character recognition, and store the screenshots and results in a database on the local machine hard drive. There are ways this could be useful. Can’t remember what website had that recipe you saw? Want to revisit a now-deleted tweet? Is your Google-fu failing you to find a news story you read last week? Recall saw it, and Recall remembers. But what else did Recall see? Every video you watched, ever website you visited, and probably some passwords and usernames you typed in.

Continue reading “This Week In Security: Recall, Modem Mysteries, And Flipping Pages” →

Hands On: Inkplate 6 MOTION

June 6, 2024 by 11 Comments

Over the last several years, DIY projects utilizing e-paper displays have become more common. While saying the technology is now cheap might be overstating the situation a bit, the prices on at least small e-paper panels have certainly become far more reasonable for the hobbyist. Pair one of them with a modern microcontroller such as the RP2040 or ESP32, sprinkle in a few open source libraries, and you’re well on the way to creating an energy-efficient smart display for your home or office.

But therein lies the problem. There’s still a decent amount of leg work involved in getting the hardware wired up and talking to each other. Putting the e-paper display and MCU together is often only half the battle — depending on your plans, you’ll probably want to add a few sensors to the mix, or perhaps some RGB status LEDs. An onboard battery charger and real-time clock would be nice as well. Pretty soon, your homebrew e-paper gadget is starting to look remarkably like the bottom of your junk bin.

For those after a more integrated solution, the folks at Soldered Electronics have offered up a line of premium open source hardware development boards that combine various styles of e-paper panels (touch, color, lighted, etc) with a microcontroller, an array of sensors, and pretty much every other feature they could think of. To top it off, they put in the effort to produce fantastic documentation, easy to use libraries, and free support software such as an online GUI builder and image converter.

We’ve reviewed a number of previous Inkplate boards, and always came away very impressed by the attention to detail from Soldered Electronics. When they asked if we’d be interested in taking a look at a prototype for their new 6 MOTION board, we were eager to see what this new variant brings to the table. Since both the software and hardware are still pre-production, we won’t call this a review, but it should give you a good idea of what to expect when the final units start shipping out in October.

Continue reading “Hands On: Inkplate 6 MOTION” →

Is That A Triboelectric Generator In Your Shoe?

June 6, 2024 by 20 Comments

The triboelectric effect is familiar to anyone who has rubbed wool on a PVC pipe, or a balloon on a childs’ hair and then stuck it on the wall. Rubbing transfers some electrons from one material to the other, and they become oppositely charged. We usually think of this as “static” electricity because we don’t connect the two sides up with electrodes and wires. But what if you did? You’d have a triboelectric generator.

In this video, [Cayrex] demonstrates just how easy making a triboelectric generator can be. He takes pieces of aluminum tape, sticks them to paper, and covers them in either Kapton or what looks like normal polypropylene packing tape. And that’s it. You just have to push the two sheets together and apart, transferring a few electrons with each cycle, and you’ve got a tiny generator.

As [Cayrex] demonstrates, you can get spikes in the 4 V – 6 V range with two credit-card sized electrodes and fairly vigorous poking. But bear in mind that current is in the microamps. Given that, we were suprised to see that he was actually able to blink an LED, even if super faintly. We’re not sure if this is a testament to the generator or the incredible efficiency of the LED, but we’re nonetheless impressed.

Since around 2012, research into triboelectric nanogenerators has heated up, as our devices use less and less power and the structures to harvest these tiny amounts of power get more and more sophisticated. One of the coolest such electron harvesters is 3D printable, but in terms of simplicity, it’s absolutely hard to beat some pieces of metal and plastic tape shoved into your shoe.

Continue reading “Is That A Triboelectric Generator In Your Shoe?” →

The Pi Pico, An SDR Receiver Front End

June 5, 2024 by 22 Comments

Making a software defined radio (SDR) receiver is a relatively straightforward process, given the right radio front end electronics and analogue-to-digital converters. Two separate data streams are generated using clocks at a 90 degree phase shift, and these are passed to the software signal processing for demodulation. But what happens if you lack a pair of radio front ends and a suitable clock generator? Along comes [Mordae] with an SDR using only the hardware on a Raspberry Pi Pico. The result is a fascinating piece of lateral thinking, extracting something from the hardware that it was never designed to do.

The onboard RP2040 ADC is of course far too slow for the task, so instead an input is used, with a negative feedback arrangement from another GPIO to form a crude 1-bit ADC. A PIO peripheral is then used to perform the quadrature mixing, resulting in the requisite pair of data streams. At this point these are sent over USB to GNU Radio for demodulating, mainly for convenience rather than necessarily because the microcontroller lacks the power.

The result is a working SDR front end, demonstrated pulling in an FM broadcast station. The Pico has to be overclocked to reach that frequency and it’s more than a little noisy, but we’re extremely impressed with how much has been done with so little. Oddly it isn’t the first Pico SDR we’ve seen, but the previous one was a much more conventional and lower-frequency affair for the European Long Wave band.