This is a heavily-modified version of Sonic 1's SMPS sound driver (which itself is a modified SMPS 68k Type 1b). It is designed to maximise compatibility with music from Sonic 2, Sonic 3 & Knuckles, and Chaotix.
You can find more information at the GitHub repository's wiki: https://github.com/Clownacy/Sonic-2-Clone-Driver-v2/wiki
This driver is designed for use with 'The Macroassembler AS', found here: http://john.ccac.rwth-aachen.de:8000/as/
More information at: https://forums.sonicretro.org/index.php?showtopic=32801 https://sonicresearch.org/community/index.php?threads/sonic-2-clone-driver-v2.4621/