Rare BOSS Rhythm Section DR-5 This unit is ideally suited for guitarists, as the input is arranged like a guitar fretboard. You can input chords even if you don't know keyboard chords, as long as you know guitar chords. I've never seen such a unique product before or since. It also has a tuner. It seems it can also run on batteries. I didn't know that until today. In addition to a drum machine, it can also program backing tracks using 256 tones for bass, keyboard, etc., with 19-note polyphony and 4 tracks (including 1 drum track). It's possible to input a guitar, as it was a time when synth guitars were gaining attention. The following operations have been confirmed using a BOSS adapter: ・Input (input/playback) ・Volume output ・Guitar input ・Headphone output ・LINE output ・Single note and chord input ・Screen display (no defects) ・No battery errors at startup ・MIDI synchronization ・The 5th image shows a DEMO performance Accessories: Instruction manual [Roland Pamphlet URL] https://www.roland.com/jp/lp/catalog_museum/pdf/NAM-1975.pdf