Many years now of research and simulation of the system (I led the restoration of the computer mentioned in the article). There's not a single place where you can read everything, unfortunately, aside from the comment above. We're planning on making a video on it in the future. But I can cite sources:

CDU theory of operation (starting PDF page 15): http://www.ibiblio.org/apollo/Documents/HSI-208435-003.pdf

CDU coarse module schematic: https://archive.org/stream/apertureCardBox462NARASW_images#p...

Grumman memo (from 1968!) describing the problem, and mentioning it is due to the reference switching to a 15V 800Hz source: https://www.ibiblio.org/apollo/Documents/Memo-GAEC_LMO_541_1...

Excerpt from the LM-8 Systems Handbook showing the reference voltage RR switch wiring: https://i.imgur.com/fMsQ7RI.png

Don Eyles describes the software side best in his book Sunburst and Luminary (which I highly recommend) but he also talks about it in some detail on his website: https://doneyles.com/LM/Tales.html