The Atari 600XL and 800XL are identical in terms of capabilities. The 600XL, unlike the 800XL, only had 16KB RAM. However, this could also be expanded to 64KB.
Both machines sold very well and stood as direct competitors against the Commodore 64. However, it never managed to reach these numbers.
The Atari XL had extensive graphics thanks to the advanced custom chips in the machine at the time. Striking was the large color range of 256 different colors, which was a lot for that time. The color range was further increased by hobbyists / coders from the Atari XL Demo Scene.
The XL machine also offered a good quality sound system, namely the POKEY chip. With this chip they were able to go in various sound directions.