for sale: Drone synth from vintage calculator

I modified this 1986 Texas Instruments calculator to be a synth drone! Features: - turn knob to adjust Pitch. - 4 of the buttons produce special high-pitched sounds - Filter switch, for smoother/harsher sound. - Drop button, which causes a drop in pitch, and can also be held down to reset the calculator. - light-up Interrupt button, to interrupt sound output. - Out selector switch, to send to either its internal speaker, or to amp. - vintage knobs, from a 1983 keyboard - green vacuum-florescent display. - vintage, lo-fi internal speaker - 1/4“ jack for connecting to amp. - has an attached AC adapter, which plugs into a wall outlet. - it’s about 12 inches square.