Simplify the following text for a Grade 8 native English-speaking person.
Original: The Atari 5200 did not fare well commercially , compared to its predecessor , the Atari 2600 . Among the criticisms raised towards the initial version of the Atari 5200 is that it is fully incompatible with the software library of the Atari 2600 .
Simplified: The Atari 5200 could not run software for the still-popular Atari 2600 .