sequencer

57 Articles

Linus Live-Codes Music On The Commodore 64

October 16, 2024 by 12 Comments

In this tremendously educational video, [Linus Åkesson] takes us through how he develops a synthesizer and a sequencer and editor for it on the Commodore 64, all in BASIC. While this sounds easy, [Linus] is doing this in hard mode: all of the audio is generated by POKE, and it gets crazier from there. If you’re one of those people out there who think that BASIC is a limited language, you need to watch this video.

[Linus] can do anything with POKE. On a simple computer like the C64, the sound chip, the screen chips, and even the interrupts that control program flow are all accessible simply by writing to the right part of memory. So the main loop here simply runs through a lot of data, POKEing it into memory and turning the sound chip on and off. There’s also a counter running inside the C64 that he uses to point into a pitch lookup table in the code.

But the inception part comes when he designs the sequencer and editor. Because C64 BASIC already has an interactive code editor, he hijacks this for his music editor. The final sequencer interface exists inside the program itself, and he writes music in the code, in real time, using things like LIST and editing. (Code is data, and data is code.) Add in a noise drum hack, and you’ve got some classic chiptuney sounds by the end.

We love [Linus]’s minimal C64 exercises, and this one gets maximal effect out of a running C64 BASIC environment. But that’s so much code in comparison to his 256-byte “A Mind is Born” demo. But to get that done, he had to use assembly.

Thanks [zogzog] for the great tip!

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Digital Audio Workstation In A Box

September 23, 2024 by 4 Comments

Although it’s still possible to grab a couple of friends, guitars, and a set of drums and start making analog music like it’s 1992 and there are vacant garages everywhere yearning for the sounds of power chords, the music scene almost demands the use of a computer now. There are a lot of benefits, largely that it dramatically lowers the barrier to entry since it greatly reduces the need for expensive analog instruments. It’s possible to get by with an impressively small computer and only a handful of other components too, as [BAussems] demonstrates with this tiny digital audio workstation (DAW).

The DAW is housed inside a small wooden box and is centered around a Behringer JT-4000 which does most of the heavy lifting in this project. It’s a synthesizer designed to be as small as possible, but [BAussems] has a few other things to add to this build to round out its musical capabilities. A digital reverb effects pedal was disassembled to reduce size and added to the DAW beneath the synthesizer. At its most basic level this DAW can be used with nothing but these components and a pair of headphones, but it’s also possible to add a smartphone to act as a sequencer and a stereo as well.

For a portable on-the-go rig, this digital audio workstation checks a lot of the boxes needed including MIDI and integration with a computer. It’s excellent inspiration for anyone else who needs a setup like this but doesn’t have access, space, or funds for a more traditional laptop- or desktop-centered version. For some other small on-the-go musical instruments we recently saw a MIDI-enabled keyboard not much larger than a credit card.

ISD1700 Based Lo-Fi Sampler

April 10, 2023 by 5 Comments

Custom music instruments here at Hackaday range from wacky to poignant. OpnBeat by [Hiro Akihabara] focuses on something different: simplicity.

There are few buttons, the design and code are optimized to be straightforward and easy to modify, and the interface is slick. Eight musical keys complement three interface keys and a knob. An Arduino Nano powers the main brains of the system but the music generation comes from eight Nuvoton ISD1700s controlled over SPI by the Nano. The beautifully laid-out PCB is 110mm by 180mm (4.33″ by 7″), so cases can easily be printed on smaller FDM printers. All the switches are Cherry MX switches for the beautiful tactile feedback.

The code, PCB, and 3D case files are all available on GitHub. We love the thought that went into the design and the focus on making it easy to recreate. It might be quite as cute and simplified as this twelve-button musical macro pad, but the two together could make quite the band.

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Sequencing The Vintage Way

January 24, 2023 by 5 Comments

For most of us, an 8-bit microcomputer means one of the home computers which set so many of us on our way back in the 1980s. But this ignores an entire generation of 1970s 8-bit machines which filled the market for affordable office and industrial desktop computing before we were seduced by Pac-Man or Frogger. It’s one of these, an SWTPC 6809, that’s found its way into the hands of [Look Mum No Computer], and in direct contradiction to his branding, he’s used it to control a synthesizer.

As you’d expect from the name, the computer hides a 6809 processor, and comes from the end of the 1970s when that chip had been released in an effort to stave off the market threat from the likes of Zilog and MOS Technologies. It has an SS-50 bus motherboard, and the saga in the video below the break is as much about the production of a custom DAC and trigger port for it to drive the synth as it is about troubleshooting a four-decade-old computer. It’s a credit to SWTPC that the machine is largely working after all this time, however it succumbs to some damage during the development of the interface.

At the end though, there’s a fully functional sequencer on a 1970s computer, playing some pretty good electronic music from an analogue synth. This is EXACTLY the future we were promised, back in 1979!

Long-time readers will know this isn’t the first SWTPC that has graced these pages.

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Rope Core Drum Machine

November 6, 2022 by 7 Comments

One of our favorite musical hackers, [Look Mum No Computer] is getting dangerously close to building a computer. His quest was to create a unique drum machine, inspired by a Soviet auto-dialer that used rope core memory for number storage. Rope memory is the read-only sibling to magnetic core memory, the memory technology used to build some beloved computers back in the 60s and early 70s. Rope core isn’t programmed by magnetizing the ceramic donuts, but by weaving a wire through them. And when [Look Mum] saw the auto-dialer using the technology for a user-programmable interface, naturally, he just had to build a synth sequencer.
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Sight And Sound Combine In This Engaging Synthesizer Sculpture

October 23, 2022 by 2 Comments

We’ll always have a soft spot for circuit sculpture projects; anything with components supported on nice tidy rows of brass wires always captures our imagination. But add to that a little bit of light and a lot of sound, and you get something like this hybrid synthesizer sculpture that really commands attention.

[Eirik Brandal] calls his creation “corwin point,” and describes it as “a generative dual voice analog synthesizer.” It’s built with a wide-open architecture that invites exploration and serves to pull the eyes — and ears — into the piece. The lowest level of the sculpture has all the “boring” digital stuff — an ESP32, the LED drivers, and the digital-to-analog converters. The next level up has the more visually interesting analog circuits, built mainly “dead-bug” style on a framework of brass wires. The user interface, mainly a series of pots and switches, lives on this level, as does a SeeedStudio WIO terminal, which is used to display a spectrum analyzer of the sounds generated.

Moving up a bit, there’s a seemingly incongruous vacuum tube overdrive along with a power amp and speaker in an acrylic enclosure. A vertical element of thick acrylic towers over all and houses the synth’s delay line, and the light pipes that snake through the sculpture pulse in time with sequencer events. The video below shows the synth in action — the music that it generates never really sounds the same twice, and sounds like nothing we’ve heard before, except perhaps briefly when we heard something like the background music from Logan’s Run.

Hats off to [Eirik] for another great-looking and great-sounding build; you may remember that his “cwymriad” caught our attention earlier this year.

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LMN-3: Putting The ‘OP’ In Open Source Synthesizers

June 14, 2022 by 10 Comments

Some projects you come across simply leave you in awe when you look at the thought and the resulting amount of work that went into it, not only for the actual implementation, but everything around it. Even more so when it’s a single-developer open source project. [Stone Preston]’s synth / sampler / sequencer / DAW-in-a-box LMN-3 absolutely fits the description here, and it seems like he has set his heart on making sure everyone can built one for themselves, by providing all the design files from case down to the keycaps.

The LMN-3 (LMN as in “lemon”, not “comes before the OP“) is intended as a standalone, portable digital audio workstation, and is built around a Raspberry Pi 4 with a HyperPixel display for the user interface. The UI itself, and with it the core part of the software, was created using the Tracktion Engine, which itself uses the JUCE framework and combines your typical synthesizer, sequencer, and sampler features with the DAW part to handle recording, editing, and mixing. The remaining hardware is a custom-designed PCB with a set of function and keyboard buttons, along with a pitch bend joystick and four rotary encoders with push buttons that serve as main input handlers. Oh yes, and a Teensy board.

The UI is actually entirely controlled via MIDI commands, and custom firmware on the Teensy is translating the input events from buttons, encoders, and joystick accordingly. This essentially decouples the hardware from the software, and using a cross-platform framework underneath, you can also run the UI standalone on your computer and use any 3rd-party MIDI controller you like. Or then, as [Stone] thought really about everything, use a hardware emulator he created in addition. You could even leave out the Raspberry Pi and software altogether and turn this into a pure MIDI controller. If that sounds tempting, but you’re looking for something with more knobs and sliders instead of buttons, check out the Traktorino. And if you actually prefer a mouse as input device, there’s always something running in a browser.

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