Good news - Olivieryuyu started his own blog:
The blog is mainly dedicated to Nintendo 64 RCP chip. It is not mere technical specifications, which you can find on Wiki. No, it's different. Olivieryuyu successfully decoded from scratch several microcodes for RSP, from poorly written microcode for Toukon Road to masterpiece graphic microcode created by Factor 5 for Battle for Naboo. It gave him ideas how to write a custom optimized microcode. You will find great amount of ideas, in-depth information and even practical results in his blog!