From what I know, there aren't too many for 4 op chips, specifically. I learned mostly just by looking at what other people have made, in addition to my own experimentation. This is probably the best resource I've seen so far. It does a great job covering the basics of FM, as well as how to make your own instruments: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-cDJ1z-4YsYM.htmlsi=oSfMl-7Zb68uZMZU
For the oscilloscope, I actually use a different program called Corrscope that renders the video seperately. All I have to do in Furnace is export wav files for each channel and one for all of the channels. Then, I throw the audio into Corrscope, change some settings, namely the resolution and amplification, and then hit "Render to Video" You can find a link to Corrscope in the description.
![Spirit of Competition (Sega Genesis, YM2612 + SN76489) [Original]](/img/logo.svg){kind=logo}
