Hacked Tape Player Makes For A Unique Instrument

September 25, 2019 by Tom Nardi 11 Comments

[Gijs Gieskes] is certainly no stranger to hacked cassette players, but his latest triumph may well be the most approachable project for anyone looking to explore the world of unorthodox tape unspooling. By attaching a fairly simple add-on PCB to a modern portable cassette player, the user is able to modify the playback speed of the tape at will. The skillful application of such temporal distortions leads to wonderfully abstract results.

The board that [Gijs] has come up with uses four potentiometers and matching push buttons to allow the user to set different playback speeds that they can engage with the push of the button. There’s also a fifth potentiometer to augment the “global” speed as well as an override switch. During playback, these controls can be used to arbitrarily tweak and augment the sound of samples contained on a the looping cassette.

If that’s a little hard to conceptualize, don’t worry. [Gijs] has provided some examples of how the the rapid adjustment of playback speed offered by this “Zachtkind” can add a fascinating level of complexity to sounds and melodies. The assembled player is available for purchase ready to go, but he also provides kits and a detailed installation guide for those who’d rather build it themselves.

Going all the way back to 2005, [Gijs] and his incredible creations have been a staple of Hackaday. From the Arduino video sampler to the array of oddly musical analog clocks, we never cease to be in awe of this exceptionally prolific hacker.

Analog Gauges Keep An Eye On Computer Performance

September 19, 2019 by Lewin Day 15 Comments

Keeping an eye on your computer’s resource utilization can be useful, particularly if you’re regularly doing computationally intensive tasks. While it’s entirely possible to achieve this with software tools, creating a dedicated hardware monitor can be cool too. [Sasa Karanovic] did just that, with a set of old-school analog gauges.

The build uses an STM32 microcontroller to drive a series of four galvanometers through an MCP4728 digital-to-analog converter. Data on CPU, memory, network and GPU utilization is collected by a Python script, and sent over a USB serial connection. This data drives the four-channel DAC, which in turn creates the voltages which control the needle position on the gauges. Aesthetically, the build features a few nice touches, including custom gauge faces and a 3D printed enclosure with a tasteful matte finish. A custom PCB keeps the electronics and wiring neat and tidy.

[Sasa] does a great job of explaining the basic theory of the device, as well as practical considerations for working with galvanometer-based gauges. It would make a great weekend project for anyone seeking to add some vintage charm to their desktop rig. There’s also scope to monitor other variables, like hard drive usage or CPU temperature. There’s bonus points if you integrate this into a laptop; the tip line would love to know. We’ve seen LED-based monitoring systems before, too. Video after the break.

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Tool Rolls, The Fabric Design Challenge That Can Tidy Up Any Workshop

September 18, 2019 by Kristina Panos 31 Comments

You’ve designed PCBs. You’ve cut, drilled, Dremeled, and blow-torched various objects into project enclosurehood. You’ve dreamed up some object in three dimensions and marveled as the machine stacked up strings of hot plastic, making that object come to life one line of g-code at a time. But have you ever felt the near-limitless freedom of designing in fabric?

I don’t have to tell you how satisfying it is to make something with your hands, especially something that will get a lot of use. When it comes to that sweet cross between satisfaction and utility, fabric is as rewarding as any other medium. You might think that designing in fabric is difficult, but let’s just say that it is not intuitive. Fabric is just like anything else — mysterious until you start learning about it. The ability to design and implement in fabric won’t solve all your problems, but it sure is a useful tool for the box.

WoF? Fat quarter? How much is a yard of fabric, anyway?

To prove it, I’m going to take you through the process of designing something in fabric. More specifically, a tool roll. These two words may conjure images of worn, oily leather or canvas, rolled out under the open hood of a car. But the tool roll is a broad, useful concept that easily and efficiently bundles up anything from socket wrenches to BBQ utensils and from soldering irons to knitting needles. Tool rolls are the best in flexible, space-saving storage — especially when custom-designed for your need.

In this case, the tools will be pens, notebooks, and index cards. You know, writer stuff. But the same can just as easily organize your oscilloscope probes. It’s usefully and a great first foray into building things with fabric if this is your first time.

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Pizza Oven Build Exercises Forgotten Gym Ball

September 18, 2019 by Kristina Panos 6 Comments

See, this is what happens when pizza lovers follow their dreams. It probably started innocently enough for [phammy57]—he got a pizza stone, then maybe one of those big rocking pizza cutters. Maybe he even learned how to toss the dough high in the air. But every time [phammy57] slid one of those homemade pies into the electric oven, the nagging feeling grew a little stronger. Eventually, he gave in to making pizza the way it’s supposed to be made, and built a wood-fired oven.

The most intriguing thing about this build is also the most important: this pizza preparer pivots on a gym ball, which served as the base for forming the oven. To do this, [phammy57] pushed the ball halfway through a hole in a big piece of plywood, effectively creating the world’s largest Pogo Bal (remember those?). Then he applied plastic wrap to the ball as a mold release, and laid down a thick mixture of vermiculite, cement, and water.

[phammy57] built the base from lightweight blocks, sculpting a nice arch for the top of the wood storage area. Once the dome was fastened to the base with the opening cut and outlined with brick, he cut a vent hole and built the chimney. Finally, it was time to add insulating blanket material, chicken wire, more vermiculite, and coat of plaster to finish. Take a brief look inside after the break.

It’s a long process of building, curing, and burning in, but the end result looks fantastic. We bet it pizzas like a champ, too. Probably gives this 45-second pizza oven a run for its money.

[Ed Note: If you’re still having trouble parsing the title, try it out with “build” as a noun and “exercises” as a verb.]

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Building Video Pong With Discrete Components

September 17, 2019 by Lewin Day 19 Comments

Pong is a classic from the very dawn of the video game era. Recreating it remains a popular exercise for those new to coding. However, its simple logic makes this game particularly suited to an all-hardware build; something which [Glen] tackles with aplomb.

Not content to take the easy way out, [Glen] went for a particularly hardcore method of construction. The game uses absolutely zero integrated circuits in its construction. Instead, it relies upon the services of 431 bipolar transistors, 6 JFETs and 826 diodes. Everything is laced together on protoboard, connected with a neatly organised nest of colored wires. Schematics are available for the curious.

It’s a full featured build, too. Video output is in color, scores are displayed at the top of the screen, and there’s even stereo panning for the sound effects. It just goes to show what some humble components can do when put to work in the right way. We’ve seen some of [Glen]’s work before too, for example in this op-amp bouncing ball device. Video after the break.

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Upping The Story-Telling Game With Dialog And The Å-Machine

September 16, 2019 by Maya Posch 5 Comments

During the decades since Infocom released their interactive story game Zork to world-wide acclaim for microcomputers, the genre of interactive fiction (IF) is still immensely popular, with a surprising number of modern IF works targeting Infocom’s original Z-Machine runtime for 8-bit micocomputers. We’ve seen a number of improved runtimes and languages for the platform over the years, with [Linus Åkesson]’s Dialog language a newcomer.

Covering the technical details about the language in this thread at IntFiction, the interesting aspect about this language is that while it has a compiler that compiles it to Z-code for the Z-Machine, [Linus] has also implemented a new runtime, called the ‘Å-Machine‘, since ‘Å’ follows ‘Z’ in the alphabet (if you’re Swedish, that is). This runtime should allow for larger stories and other features that make better use of more resources, while still allowing smaller stories to work on old hardware. Unfortunately the only Å-Machine implementation at this point is written in JavaScript, which is not known to work particularly well on Commodore 64 or even Amiga 500 systems.

As for Dialog itself, its documentation provides a detailed overview of the language’s capabilities, which claims to be inspired by both Inform 7 and Prolog. Its goals are to be easy to follow, with a minimal number of language concepts, and high performance. As the documentation notes, many Z-Machine based stories exist today that are unplayable on vintage hardware due to lack of optimization.

We covered Zork and the Z-Machine a while ago in some detail. We think it’s great to see that there’s still so much interest in the platform. Maybe someone will write an Å-Machine implementation for a Commodore or MSX system one of these days to see how it compares to Infocom’s Z-Machine. Here’s to another few decades of the Zork-legacy.

Scratch Built Media Player Channels 1980s Design

September 15, 2019 by Tom Nardi 51 Comments

No, you aren’t looking at a 30 year old Teac graphic equalizer that somebody modified. The MWA-002 Network Music Player created by [GuzziGuy] is built entirely from new components, and easily ranks up there with some of the most gorgeous pieces of homebrew audio gear we’ve ever seen. Combining modular hardware with modern manufacturing techniques, this 1980s inspired build is a testament to how far we’ve come in terms of what’s possible for the dedicated hacker and maker.

The enclosure, though it looks all the world like a repurposed piece of vintage hardware, was built with the help of a CNC router. It’s constructed from pieces of solid oak, plywood, and veneered MDF that have all been meticulously routed out and cut. Even the front panel text was engraved with the CNC and then filled in with black paint to make the letters pop.

Internally, the MWA-002 is powered by a Raspberry Pi 3 running Mopidy to play both local tracks and streaming audio. Not satisfied with the Pi’s built-in capabilities, [GuzziGuy] is using a Behringer UCA202 to produce CD-quality audio, which is then fed into a TPA3116 amplifier. In turn, the output from the amplifier is terminated in a set of female jacks on the player. Just like the stereo equipment of yore, this player is designed to be connected to a larger audio system and doesn’t have any internal speakers.

The primary display is a 256×64 Futaba GP1212A02A FVD which has that era-appropriate glow while still delivering modern features. [GuzziGuy] says it was more difficult to interface with this I2C display than the LCDs he used in the past due to the lack of available libraries, but we think the final product is proof it was worth the effort. He bought both the VFD spectrum analyzer and LED VU meter as turn-key modules, but the center equalizer controls are completely custom; with dual MCP3008 ADCs to read the state of the sliders and the Linux Audio Developer’s Simple Plugin API (LADSPA) to tweak the Pi’s audio output accordingly.

We’re no strangers to beautiful pieces of audio gear here at Hackaday, but generally speaking, most projects involve modernizing or augmenting an existing device. While those projects are to be admired, the engineering that goes into creating something of this caliber from modular components and raw building materials is really an accomplishment on a whole different level.