Weird graphical glitch on pitfall!

[Elijah]

Hello everyone,

I'm currently grappling with a dilemma that seems to be somewhere in the realms of hardware, programming, or emulators concerning the Atari 2600. While playing a game of Pitfall (which for the record, I'm very bad at), I inadvertently left my emulator running in the background after I died, only to observe a fascinating phenomenon: the color pallet started changing after a while. Now, I'm not quite sure whether this is a hardware glitch, a programming quirk, or simply an emulator idiosyncrasy.

Given my relatively novice status in programming for the Atari, I'm eager to learn the reasons behind these color transformations. Any insights or knowledge on what might be causing this would be immensely appreciated! Attached below are screenshots capturing the intriguing color shifts. Thank you and I will be testing other games for this interesting glitch.

Yours,
Elijah

[Thomas Jentzsch]

That's normal for many old games. It is a screensaver.

[Andrew Davie]

Yes, it's sometimes called "attract mode".  On old CRT TVs it was possible to "burn in" an image onto the TV phosphor if it was left displaying the same image/colours for a long time. This would permanently damage the phosphor and leave the image permanently "ghosted" onto the picture.  By cycling colours like you have observed, it was reducing the chance of phosphor burning. Welcome to the esoteric world of 1970s quirky hardware . This "attract mode" colour cycling was done by the programmer, so it varied from game to game. It wasn't too long before this kind of thing was abandoned, so it's not terribly common in games.

[Thomas Jentzsch]

Mr. Do's Castle still has it in 1984 (screen goes black). Many larger games have real attract modes and/or switch screens, so screen saving was not relevant anymore.

[Elijah]

Awesome, thanks guys!

[OliviaParker]

That's great, I'm also looking for this solution, thanks.