The card is based on the Cirrus/Crystal CS4237 chip, and originally designed for my Mini DOS gaming PC project - https://www.youtube.com/watch?v=ZBsv-jRiIT8
It's only designed to give very basic audio functionality and isn't audiophile grade by any means. The power supply filtering is garbage, there's no proper OPL or intelligent mode MPU, and the analog section is unbuffered with an iffy grounding scheme. The BOM could use some optimisation too (I have both 0603 and 1206 0.1uF caps for some reason). It does at least have a waveblaster port (which I've paired with a Dreamblaster S2 for my gaming PC).
Despite all this it runs all the games I want to run with acceptable levels of noise/hum/etc. It serves my use-case perfectly and I imagine other people will find it useful too.