Why did the Atari 2600 console design change so much

[Mr SQL]

 

 

The 2 moved switches are the result of the new (cheap) all-in-one motherboard. The result of this revision is a bad picture quality on all 4switch models. The 2600 JR picture quality is almost as good as on the 6switchers...

 

Excellent point Mr VCS! Sometimes though, the baddness is good as Boisy Pitre and Bill Loguidice put it in their awesome CoCo book The Colourful History of Tandy's Underdog Computer:

 

After Tandy cleaned up the chroma leaking into the RF they lost the awesome artifact colourset and plunged their best games into a bleak and desolate world of black and white graphics. This never made it through to production and they went out of their way to preserve the leaking chroma (and even intensified the colours).

 

I designed my last 2600 game, KC Monster Maze to take maximum advantage of colour artifacting on the VCS and while a six swith and a Junior will show some artifact colours on the maze walls, only the badness of the four switch models will display the artifacting really thickly and show multicolour sprites with true lighting and shadow effects on the characters; the baddness is gorgeous!