Vintage synth

Citation : main features:

* 32 mini keys
* polyphony 2 voices
* 8 OBS preset sounds {clarinet, electric guitar, violin, oboe, xylophone, piano, banjo, harpsichord}
* 8 OBS preset rhythms with interesting percussion {pops, disco, latin, 16beat, swing, slow rock, march/ polka, waltz}
* demo button (monophonic "Yankee Doodle" )
* tempo control (16 steps?)
* simple sequencer (monophonic record & playback, but it can play together with both keyboard voices)
* volume control (4 steps)
* sound generator is digital squarewave (crystal clocked)
* drums are digital squarewave {medium blip, low blip}, cymbal/ hihat = metallic digital waveform
* CPU="Yamaha YM2410, 76 07 85 E" (24 pin DIL)
* alarm tone (2 notes) warns to save batteries.