The Juno has four independent waveform generators (pulse, sawtooth, square wave sub-oscillator, and noise). The pitch can be modulated with the bender and with the Low Frequency Oscillator (LFO) to give a vibrato effect. The output is then sent through:

A High Pass Filter (HPF) which either boosts or cuts the bass.
A Voltage Controlled Filter (VCF). This is a resonant low pass filter which cuts high frequency components of the sound. The cutoff level can be controlled by the combination of an adjustable slider, the Envelope Generator (ENV), the Low Frequency Oscillator (LFO), and optionally the bender. There is also a slider which adjusts the resonance level.
A Voltage Controlled Amplifier (VCA) which adjusts the volume level of the sound. The VCA can be controlled by the Envelope Generator (ENV).
A Chorus function which can perform stereo phasing effects on the signal to give a "fuller" sound.
Other features include:

Portamento, which allows the synthesizer to "slide" between notes.
A "unison" mode which assigns all six oscillators to the same note, essentially turning the Juno into a big fat monophonic synth. (Great for big fat unpredictable basslines...buckets o' fun when used with portamento.)
Many functions can be controlled externally through MIDI system exclusive messages.
High-tech storage and retrieval of patches to audio cassettes.
The Juno uses Digitally Controlled Oscillators (DCOs) to produce sound rather than the older style Voltage Controlled Oscillators (VCOs) found on many vintage synthesizers. The advantage of a DCO is that it is more stable and less susceptible to the tuning problems, especially due to temperature changes, that can be a problem with many analog synths.

The Juno-106 is one of the most loved and used synthesizers by professionals and hobbyists alike! William Ørbit, Uberzone, Norman Cook (Fatboy Slim), Autechre, BT, Vince Clarke, Moby, 808 State, Underworld, Leftfield, Fluke, Josh Wink, Todd Terry, Depeche Mode, Eat Static, Biosphere, The Prodigy & The Chemical Brothers

Below is information on the self test and midi functions of the 106

roland_Juno-106.txt

As of 2010, this synth has been sold