short demo of using the free open source modular synthesizer program - VCV RACK - to build your own software "keyable" Morse Code Practice Oscillator
the plugins shown used, are some of the basic default plugins that install with the VCV RACK program....the Morse Code CPO setup uses a typical basic framework to make a midi keyed synthesizer....
1. MIDI INPUT (MIDI to CV)
2. VOLTAGE CONTROLLED OSCILLATOR (VCO-1)
3. ADSR (set the rise time and fall time and CW waveshape)
4. VCA (use LINEAR or EXPONENTIAL keying CW element edges)
5. Audio Interface - for managing audio output ports
some more info on VCV RACK modular synth'N: