Improve CD Sound By Shaving?

September 7, 2022 by 89 Comments

We always enjoy the odd things that people do to try to get better audio reproduction. Exotic cables, special amplifiers, and higher resolution digitization come to mind.  Most of this is dubious, at best, but [Techmoan] brings up something we must have missed back in the day: shaving CDs with a gadget that was marketed as the “CD Sound Improver.” The theory is that bad CD reproduction comes from light scatter of the laser. The solution, according to the maker of this vintage equipment, is to cut a 36-degree bevel to act as a light trap. You can see the gadget in the video below.

The device claims it reduced vibration, improved audio, and even helped DVDs playback better video. As you might imagine, this has little hope of actually working. The box is essentially a motor-driven turntable, a razor blade, and a port for a vacuum cleaner to suck up the mess. You were told to color the edge with a marker, too.

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The MOS 7600 Video Game Chip Gives Up Its Secrets

September 7, 2022 by 5 Comments

A good chip decapping and reverse engineering is always going to capture our interest, and when it comes from [Ken Shirriff] we know it’s going to be a particularly good one. This time he’s directed his attention to the MOS 7600 all-in-one video game chip (Nitter), a mostly forgotten device from the 6502 chipmaker which we featured a few weeks ago when it was the subject of a blogger’s curiosity. The question then was whether it contained a microprocessor or not and even whether it was another 6502 variant, and the answer revealed in the decapping answers that but will disappoint the 6502 camp.

On the chip is a mixture of analog and digital circuitry, with some elements of a more traditional game chip alongside a ROM, a PLA, and a serial CPU core. The PLA stores pixel data while the ROM stores the CPU code, and the CPU serves to perform calculations necessary to the games themselves. He hasn’t fully reverse-engineered either, but the two areas of the chip are mask-programmed to produce the different games with which the chip could be found.

So the answer to the original question is that there is a CPU on board, but it’s not a 6502 and the operation is a hybrid between dedicated game chip and CPU-controlled chip. What we find interesting is that this serial CPU core might have as we mused in the previous piece made the heart of a usable 1970s microcontroller, was this a missed opportunity on the part of MOS? We’ll never know, but at least another piece of early video game history has been uncovered.

Ethersweep: An Easy-To-Deploy Ethernet Connected Stepper Controller

September 7, 2022 by 35 Comments

[Neumi] over on Hackaday.IO wanted a simple-to-use way to drive stepper motors, which could be quickly deployed in a wide variety of applications yet to be determined. The solution is named Ethersweep, and is a small PCB stack that sits on the rear of the common NEMA17-format stepper motor. The only physical connectivity, beside the motor, are ethernet and a power supply via the user friendly XT30 connector. The system can be closed loop, with both an end-stop input as well as an on-board AMS AS5600 magnetic rotary encoder (which senses the rotating magnetic field on the rear side of the motor assembly – clever!) giving the necessary feedback. Leveraging the Trinamic TMC2208 stepper motor driver gives Ethersweep silky smooth and quiet motor control, which could be very important for some applications. A rear-facing OLED display shows some useful debug information as well as the all important IP address that was assigned to the unit.

Control is performed with the ubiquitous ATMega328 microcontroller, with the Arduino software stack deployed, making uploading firmware a breeze. To that end, a USB port is also provided, hooked up to the uC with the cheap CP2102 USB bridge chip as per most Arduino-like designs. The thing that makes this build a little unusual is the ethernet port. The hardware side of things is taken care of with the Wiznet W5500 ethernet chip, which implements the MAC and PHY in a single device, needing only a few passives and a magjack to operate. The chip also handles the whole TCP/IP stack internally, so only needs an external SPI interface to talk to the host device.

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How To Be A Stinkin’ Chess Cheat — Sockfish

September 7, 2022 by 18 Comments

[James Stanley] enjoys chess, isn’t terribly good at it, and has some dubious scruples. At least, that’s the setup for building Sockfish, a shoe-to-Pi interface to let you cheat at chess. We’re pretty sure only the first point is true, but the build is impressive all the same. It’s a pair of 3D printed shoe inserts, with two pressure-sensitive inputs on each insert, coupled with a vibration motor in each. Tap out your opponent’s moves during the game, and the Stockfish software will buzz instructions back to you. Just follow the instructions, and you too can be a chess master.

In practice things went a bit awry, as poking in encoded move data with one’s feet isn’t the easiest task, and discerning the subtle tickles on the toes is error-prone at best. [James] arranged a match against an unsuspecting friend (in the name of science), and managed to fat-finger (fat-toe?) the inputs on both games, leading to Sockfish instructing him to make illegal moves.

This seemed like too much cheating, even for [James], so he played the rest of each game on his own abilities, winning one of the two. Once the deed was done, our anti-hero gladly doffed his shoes to show off his gadgetry. After some debate, they concluded the device might “bring the game into disrepute” if used for greater evil. Naturally [James] is already working on an improved version.

Thanks to [Abe Tusk] for the tip!

Linux Fu: Eavesdropping On Serial

September 7, 2022 by 21 Comments

In the old days, if you wanted to snoop on a piece of serial gear, you probably had a serial monitor or, perhaps, an attachment for your scope or logic analyzer. Today, you can get cheap logic analyzers that can do the job, but what if you want a software-only solution? Recently, I needed to do a little debugging on a USB serial port and, of course, there isn’t really anywhere to easily tie in a monitor or a logic analyzer. So I started looking for an alternate solution.

If you recall, in a previous Linux Fu we talked about pseudoterminals which look like serial ports but actually talk to a piece of software. That might make you think: why not put a piece of monitor software between the serial port and a pty? Why not, indeed? That’s such a good idea that it has already been done. When it works, it works well. The only issue is, of course, that it doesn’t always work.

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Front and back of a handheld 6502 computer with bubble LED displays

The Pocket265 Is A Pocket-Sized 6502 Single-Board Computer

September 7, 2022 by 13 Comments

Single-board computers have been around ever since microprocessors became affordable in the 1970s and never went away. Today we have Raspberry Pis and LattePandas, while back in the ’70s and ’80s there were the Ferguson Big Board, the KIM-1 and a whole array of Intel SDK boards. Although functionally similar to their modern counterparts with a CPU, RAM, ROM and some basic peripherals, the old boards were huge compared to today’s tiny platforms and typically required a rather beefy power supply to operate.

It doesn’t have to be that way though, as [Aleksander] shows with the Pocket265: a handheld 6502 single-board computer somewhat reminiscent of the famous KIM-1. Like that classic machine, it’s got a hexadecimal keypad to enter programs using machine code and a row of LED displays to show the programs’ output. Unlike the KIM, the Pocket265 is small enough to hold in one hand and uses bubble LED displays, which make it look more like a programmable calculator from the 1970s. It comes with a lithium battery that makes it truly portable, as well as a sleek 3D printed case to make it more comfortable to hold than a bare circuit board.

The single ROM chip contains a monitor program that runs the basic user interface. It also makes programming a bit less tedious by implementing a number of system calls to handle things like user input and display output. A serial EEPROM enables local data storage, while a UART with a USB interface enables data transfer to other computers. If you’re interested in building and programming such a machine yourself, [Aleksander] helpfully provides code examples as well as full hardware documentation on his GitHub page.

The 6502 remains a firm favorite among hardware hackers: some projects we recently featured with this CPU include one beautifully made machine, this easy-to-build single-board computer and this huge breadboard-based contraption. Looking for something smaller? Try this tidy little board or this 6502 coupled to an FPGA.

Agrivoltaics Is A Land Usage Hack For Maximum Productivity

September 7, 2022 by 53 Comments

Land tends to be a valuable thing. Outside of some weird projects in Dubai, by and large, they aren’t making any more of it. That means as we try to feed and power the ever-growing population of humanity, we need to think carefully about how we use the land we have.

The field of agrivoltaics concerns itself with the dual-use of land for both food production and power generation. It’s all about getting the most out of the the available land and available sunlight we have.

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