From Yamaha Wiki

The Yamaha PortaSound PC-50 is an entry-level portable musical keyboard produced by the Yamaha Corporation in 1983.

Specifications

• 44 keys
• 6 voice Polyphony: Electronic organ, Violin, Clarinet, Piano, Harpsichord, and Vibraphone
• 6 rhythm patterns: March (music), Waltz, slow Rock music, Jazz rock, Swing, Cuban Rumba
• Power source: 9VDC by six C battery batteries or external
• Output ports: Jack plug headphone jack, aux RCA connector, and expression pedal.
• Input port: power in: 9-12VDC

External links

• Yamaha PC-50 Owner's Guide at manufacturer's site
• Yamaha history of electronic music instruments