Dual AY-3-8910 USB MIDI

This is a MIDI synthesizer that uses two AY-3-8910 Programmable Sound Generators (PSGs) to play music. The AY-3-8910 is a classic sound chip that was widely used in computers and gaming consoles in the 1980s. The synthesizer is built around a Raspberry Pi RP2040 microcontroller, which handles MIDI input and controls the AY-3-8910s. The two AY-3-8910s provide a total of six channels of audio. The synthesizer is powered via USB. Currently it requires special software to send MIDI data to it over serial, but I plan to add support for standard USB MIDI so that it can be used with any MIDI software.