Initially sold for ¥32,000
The Yamaha CS01 is an analog monophonic synthesizer part of the "Producer series", a family of small and affordable devices to build a home studio. In a very small footprint (roughly the width of a rack, even smaller than the DX100) it packs a 32-key keyboard, pitch and modulation wheels, an amplifier and speaker system while still offering a fine overall sound quality and enough sliders to shape the sound. Sound is produced through a pretty standard subtractive synthesis array: single VCO, high pass or low pass VCF, single EG and an LFO.
Yamaha's newly introduced breath control system lets you control the CS01's VCA and VCF using your breath via the optional breath controller. Light gray is the most common colour, but black with red accents and white with red accents were also available.
The CS01 runs on AC adaptor or batteries. It predates MIDI so there's no MIDI connection available, however kits to retrofit one are on sale nowadays.