Yamaha PSR-15 Keyboard (no cables, no case, no stand)

No MIDI ports; just a DC 9V-12V in port and an expression pedal port on the back, as well as a 6.35mm headphone jack on the front. Keyboard works perfectly fine on DC power, I have not tried to use it on battery power (it takes six 1.5V batteries) so I can’t promise anything, but I don’t know why it wouldn’t work as well. The battery panel on the bottom also does not have a back to it, though, so using a power cable would probably be safer. It has screws for music stands on the bottom. The PSR-15 is from 1984, and has six quite nice sounding synth instrument options—organ, flute, violin, trumpet, piano, and harpsichord—as well as a sustain switch, a metronome, a tempo slider, an auto-chord switch, a master volume slider, an accompaniment volume slider, and, of course, a power switch. More info on the keyboard: https://soundprogramming.net/keyboards/yamaha/yamaha-psr-15/