"My detailed study of them will show me that they were not reliable: Several errors slipped inside. The first step was a precise study of the logic of the microcomputer in order to detect all the errors. It was a very interesting step."
Fabrice Montupet made this statement in his TI(ny)-99/4A thread in June '17. So far I have not found any errors in the schematic that I have. I can imagine he has had many requests for details on his findings. I do not wish to waste his time if he has already provided this information somewhere. I did search for a while, and I found schematics for what I presumed was the PAL version of TI99/4A, because it had a TMS9928A. But then I saw that it still had a 10.7 MHz crystal, so it couldn't be PAL. A little research revealed that the TMS9929A is the PAL version of the 9928A. Since Fabrice lives in France I further presume the PAL version would be the one he uses (I think I recall him saying somewhere that the 9929A was his favorite VDP ), and this schematic would be the one that has the errors? Or perhaps he is referring to differences between the NTSC schematic and the PAL version?
I really just want to know if I need to be wary of errors in the NTSC schematic for now. However, in my search for schematics, I have not come across any for the beige version of the TI99/4A. I understand there were some significant changes made in how things are decoded in these units. Is this info out there? If so, where is it?