To save you a click, the video is someone speed-typing the source code to an emulator, with no commentary or explanation. You'd probably be better off reading the final result yourself.
Q) Is the video sped up? Or, is that your real typing speed?
A) No, it's not sped up. But the input is pre-choreographed. The computer
implements the choreography, as well as designs a part of it.
It is a TAS, except I'm not speedrunning; I'm just aiming for
15 minutes and to utilize it in the most entertaining manner.
My typing speed is not the focus of that video; it is not even
being presented except in a small part of the 2/2 video.
The focus is in the source code.
He actually wrote his own editor that he uses in the video and I believe that assists with the choreography.
Enable subtitles/closed captioning to see additional commentary provided by him about what is happening.
>the video is someone speed-typing the source code
They are not actually typing it at all, from the faq https://bisqwit.iki.fi/jutut/kuvat/programming_examples/nese...
He actually wrote his own editor that he uses in the video and I believe that assists with the choreography.