YM3812 Synth Card

Description

A couple years ago, I built a EuroRack style YM3812 synthesizer module, and throughout 2023 launched a series of 10 videos (and 10 articles) describing how all of the hardware and software works. There are still more videos to come, but a few new projects pushed things to the back burner for now.

In the 9th video, I detoured into the "SynthCard" form factor—a business card sized synthesizer standard that a few of us were playing with on Discord. This offered a fun new challenge: cramming a YM3812-based General MIDI synthesizer into a PCB the size of a business card using nothing but through-hole components.

This turned out to not only be entirely possible, but works really well with General MIDI supported video games. In fact, in the Sierra games I tested, it produced more complex and interesting sound tracks than those designed specifically for the YM3812—e.g. SoundBlaster / Adlib cards. It's all open source, so enjoy!

Details

Over the course of the project, I have rather thoroughly documented everything from the hardware to the software on my website, http://www.thingsmadesimple.com. So rather than try to re-document that information here, I am going to provide a series of links to each of the articles and videos. The source code for everything can be found on my GitHub as well as the kicad files for the business card PCB (see the article 9 folder).

Article: YM3812 Part 9: SynthCard

Turn that breadboard into a business card sized PCB!

And for reference, here are all of the other videos in the series that describe in detail how the YM3812 SynthCard works:

Article: YM3812 Part 1: Register Basics

Focuses on FM Synthesis basics, the YM3812's register map and electrically controlling the chip's pins.

Article: YM3812 Part 2: FACE Reveal

Introduces a basic implementation of the YM3812 circuit controlled by an AVR128DA28 microcontroller that we will build on in future articles. Think of it as a "Hello World" starting point that ensure the circuit works and that we can upload code to the microcontroller.