Short answers, pulled from the story.
Roland released the CompuRhythm CR-78 in 1978 and led a project with chief engineer Tadao Kikumoto. The team included Makoto Muroi as chief engineer, Hiro Nakamura designing analog voice circuits, and Hisanori Matsuoka developing software and hardware.
The 808 launched in 1980 with a list price of $895. Roland ended production in 1983 after semiconductor improvements made it impossible to restock the faulty transistors essential to its design.
Unlike its nearest competitor the Linn LM-1 the 808 generates sounds using analog synthesis rather than by playing samples. Memory chips were too expensive at the time to use pulse-code modulation for playing samples of percussion so Kikumoto proposed a drum synthesizer instead.
The 808 is noted for its powerful bass drum sound built from a sine oscillator low-pass filter and voltage-controlled amplifier. The bass drum decay control allows users to lengthen the sound creating uniquely low frequencies that flatten slightly over time possibly not by design.
In 1982 American R&B artist Marvin Gaye released the first US hit single to feature the 808 titled Sexual Healing. Gaye was drawn to the 808 because he could use it to create music in isolation without other musicians or producers.