ATI chips: Difference between Theatre 100 and 200 chipset?
 

What is the difference between Theatre 100 and 200 chipset please?

Not much. The THEATRE 200 chip has an additional 5% MPEG hardware load. THEATRE chipsets encode video with a "hybrid" method, using both hardware and software in tandem. The 200 chips are the new ones. The 100 chips were also called RAGE THEATRE chips.

All THEATRE chips from the RADEON-class AIW line-up are pretty much the same, in terms of output quality and how they act. The native resolution of the 200 is also a few pixels different from the 100, but both are very close to 704x480 native.

Thank you. I am glad that there is life in my old AIW 128 pro still!

Yes, the AIW 128 PRO is still a "modern" card.
It is definitely not obsolete for video.