I was looking at an applicaiton note for the old ICL8038 function generator IC, and came across the internal schematic of the chip. There is a triangle to sine converter at the end that looked interesting, so I assembled it in the Falstad simulator to explore its operation. I'm publishing the simulation data for anyone who wants to play with it, and including the datasheet and app note here for convenience (obviously those documents are not mine).
To run it, go to the URL below, pick Import from Text from the menu, and paste in the contents of the falstad.txt file.
http://www.falstad.com/circuit/circuitjs.html
My files are released into the public domain.