Six-Voice Polyphonic Synth

When computers and electronics were in their most nascent phases, they were largely the realm of hackers in their garages, with glorious hand-crafted wooden panels delightfully concealing their bodged-together innards.

The same was true of early synths, with the first Moogs clad in walnut cases, and while the tradition has perhaps somewhat lived on in the form of wooden side panels and cases for modular synths, it’s not every day that you see a recently-designed keyboard in a wooden case. So we were particularly intrigued by Albert Nyström’s Teensy-Poly6!

The Teensy-Poly6 is powered by a Teensy 3.5, and uses relatively few other components beyond the salvaged M-Audio Keystation 49 keys. The code and schematic can be found on GitHub, and the below video gives a glorious demonstration of the instrument’s capabilities. We’re not sure if the name is a direct reference to 1981’s Korg Polysix, or just a coincidence, since they both feature six-voice polyphony, but the Korgs currently fetch $1-2K on eBay, which makes the DIY Teensy synth look like an absolute steal with a BOM cost of around $120!

Beatmaster2k – Sequencer Using Novation Launchpad

MrCanvas decided to have a go at creating his dream self-contained sequencer, in the form of the Beatmaster2k!

In the mid 1990s, so-called “groovebox” devices began to emerge, which allowed electronic music producers to sequence and improvise music using a single, self-contained…well…box! As digital audio workstation (DAW) music production software became more accessible, producers began to gravitate more toward computer screens, and as control surfaces for these DAWs began to emerge, this gave the best of both worlds: knobs you can touch, with the ease-of-use and expandability of a general-purpose computing device. But not everyone wants to sit in front of a giant screen all day, which is why the industry has seen a renaissance of self-contained workstation devices in recent years.

In addition to a Teensy 4.1, the project consists of an ILI9341 display, two encoders, eight buttons via an MPC23017 I2C I/O expander, a powered USB hub, and a Novation Launchpad Mini Mk3 control surface. It currently supports seven tracks with eight 128-column polyphonic patterns each, edited as matrices on the Launchpad. The source code is available on GitHub, and you can check out the video below for demonstration of this groovebox getting groovy!

Commodore 64 Accelerator

When the Commodore 64 launched in 1982, the venerable MOS Technology 6510 that powered it clocked along at around 1 MHz, depending on region (NTSC vs. PAL).

Fast forward to 2023, and the latest Teensy 4.x models are rated at 600 MHz without overclocking. So what happens when you drag the C64 kicking and screaming four decades into the future? Ted Fried aka MicroCore Labs has the answer in the form of his Teensy 4.1-powered MCL64.

The MCL64 consists of an inexpensive PCB (open-source and available on GitHub), which hosts a Teensy 4.1, and replaces the onboard 6510 CPU. In addition to providing a cycle-accurate mode, the MCL64 may vie for the title of “world’s fastest Commodore 64” when running in accelerated mode: initial testing put it at twice the speed of 1996’s WDC 65C816S-based 20Mhz SuperCPU, with further optimizations improving performance significantly further — and that’s without pushing it to the ultimate extreme with the Teensy’s maximum overclock frequency of 912MHz!

Ted has posted several blog posts about the project, and the PCB and source code can be found on GitHub.

8086 PC Emulator with CGA Graphics

What do Two Guys from Andromeda and Bill Gates have in common? They are both responsible for code that will run on a Teensy!

Now, it’s entirely possible that none of them have heard of Teensy (as unfortunate as that may be!) let alone knew that their code ran on it, but that’s where Mike Chambers’ Teensy 3.6 based 8086 PC emulator with CGA graphics, PS2 keyboard comes in!

The project started out as a software-based emulator, but Mike was curious to see how it might perform on a microcontroller; with even the most humble Arduino out-clocking and even out MIPS-ing early PCs, it seemed like an interesting proposition. Unfortunately, even that most stalwart member of AVR’s 8-bit stable, the ATmega2560, proved no match for the job. Fortunately, Mike discovered the muscle he needed in the form of the Arm Cortex-M4 in our very own Teensy 3.6!

As thrilling as it is just to see a DOS prompt on our 320×240 display, being able to recreate Prince of Persia’s legendarily smooth motion gives you a real feel for the potential of this project – and that was before any optimization or overclocking! In the videos below, Mike also shows the Sierra Online classic Space Quest, and even Microsoft Windows 3.0 running on his Teensy tiny PC:

Mike shares his source code and which pins to connect the SPI RAM, LCD, and keyboard to in a forum post, as well as specs for the required hard drive image, which runs from microSD. Observant readers may notice that most venerable DOS-based palmtop, the HP 200LX, in the background of his project pic – perhaps foreshadowing a full-blown Teensy handheld?!