There’s a much larger series of videos about this project on YouTube as well. This EEPROM programmer was designed as part of a larger project to build an 8-bit computer from scratch.
Again, you’ll likely want more context from the full series of videos, but here’s the video describing the code: The code in /microcode-eeprom-with-flags adds functionality for a flags register to the microcode above to support conditional instructions. 8-bit computer microcode with flags register
You’ll probably want to watch the whole 8-bit computer playlist (see below) for this to really make sense, but the specific videos describing the code here are: The code in /microcode-eeprom-programmer is for programming a pair of EEPROMs to serve as an instruction decoder for an 8-bit breadboard computer.