Earlier this year I had asked a couple questions on the forum here about a project I was working on to play 'DIGIs', digital speech samples, on a C64. One question was about methods to toggle a bit flag and the other was about choosing which ISR to use at run-time. Lot's of great suggestions were offered and in particular @chromatix had some really great suggestions.
I finally got around to making a video about how DIGIs work and how to make them. The first video is an overview on what they are, the basics on making and playing one and a look at Forest S. Mozer, a physic professor for revolutionized speech synthesis in the 1970s. He created ESS, Electronic Speech Systems and was the voice behind games like Ghostbusters and Impossible Mission.
I'm working on the second video now which goes into detail about the 'Cruncher' program which further processes the sample data to a form that will work on the C64 and the player itself complete with all the great code ideas suggested by @chromatix. When the second part is out I'll add the link to this thread.
Please note that the code is on Github and the link to it and a lot of other links are in the video description.
https://youtu.be/fvgkAWwSceI