Writing this late on Christmas Day 2019. One of my gifts is an HDMI converter & upscaler for Composite/S-Video. So far, it does what it claims.

The Nintendo 64 is one of my favorite game consoles. This one is named MOGU. It was previously used as the Mobile Office Gaming Unit. It was wheeled out on an A/V cart during lunch hours and many a laugh were had.
The lack of analog input in modern displays and televisions leaves the older consoles like the N64 stored in closets. This HDMI converter for Composite (Yellow) or S-Video (that odd cable with multiple pins that most people never used) allows one to select the input and select the output resolution.

This thing does what it says it does. Initial setup and testing is positive.
At the time purchased, this is about $35 on Amazon. The product title is “Tendak 3RCA AV CVBS Composite & S-Video R/L Audio to HDMI Converter Adapter Support 720P/1080P with 3RCA S-Video Cable for NES SNES N64 PS2 PS3 HDTV.”