Nice little brown keyboard I got for cheap in an op-shop. Case it comes with is pretty sturdy!

1980. Digital sounds (YM1104) with analogue filter.

Expression pedal just controls volume.

• Yamaha PS-3 Review - Info., demo, and disassembly.
• yamaha_portable_keyboard_ps-20 - Another (bigger) keyboard in the same line we own.
• https://files.ryliejamesthomas.net/manuals/yamaha_portasound_ps-1,2,3.pdf - Manual.