An HTML5 & Javascript emulation of Roland's final analog drum machine
Feb 20, 2011 This simulation of a Boss DR-110 drum machine was borne out of the discussion on the internet about whether or not you can do everything in HTML5 that you can do in Flash. Most of the arguments I saw for HTML5 ignored things such as RTMP and Flash's audio capabilities. I felt that particularly in the area of audio (let alone audio processing), HTML5 and javascript were severely lacking, even compared to what I could do in Flash many years ago. Having not programmed anything audio related in Javascript, however, I didn't feel as though I could qualify my qualms. To that end, I began to build on an idea I'd had about a decade ago but never had the drive to follow-through on - emulate the functionality of the last analog drum machine that Roland/Boss produced. It seemed pretty simple, mostly becuase none of the sounds on the DR-110 were adjustable. It's a sequencer, doesn't even have MIDI, and only has a half dozen of (mostly) static sounds.
So during occasional evenings, and one or two Saturdays, I set about recreating a Boss DR-110. I'd searched online for other javascript-driven drum machines, but everything I came across was (understandably) clunky and rough. There are already so many fantastic tools for creating beats that go well beyond what I felt was capable within the browser, and you learn very quickly when making something like this that timing - something incredibly important to a beatbox - is shaky at best in contemporary browsers. There's also the issue of providing audio in codecs each browser supports - and with mobile platforms, good luck getting audio playback working at all.
From the start, my intention was to post it publicly, which is part of why it took so long -- I hope that my javascript isn't total crap. Knowing that I'd be posting this to the likes of HN and Reddit has (hopefully) kept me on my toes with respect to the code. That said, I encourage you to take this code and push it further - make it more portable, clean it up, make something bigger and better with what you see here. Maybe move the knobs and the display into a canvas, if you're really into that kind of thing.
Note: Song mode and the balance knob have not been implemented yet. --Matt Dunphy bitrotten.com