I have 2 Atari 130XE, which have, besides different colors and different hardware, a different raster timing too!
Since nobody believed me, here are some photos.
Please ignore any horizontal lines. Since they were shot with my cellphone. :D
The white screen is a test by me. There are white and black areas on the screen. The black areas are filled with raster changes to be fit _excactly_ into that area. Which obviously doesnt work on the Taiwanese atari. On the chinese it works very well.