My ATV came with 2.3 . Can it safely run any previous version? For example could I "downgrade" it to 2.1 or even 1.x ?

Thank's,

ls

2.1 probably, 1.x almost definitely not. i remember speaking to davilla about this when he was working on patchstick builder, i think there is some incompatibility with a minor hardware change between 1.x and 2.x appletv's, something about a different wireless card or something like that, dont remember the exact specifics. but i do believe the conclusion was against 2.x oob appletvs running 1.x versions. Why would you want to downgrade to 1.x anyway? i can understand 2.1, but 1.x not so much.

I'm mainly interested in 2.1. The 1.x issue was more of a curiosity question. While I like the layout of the native videos with 2.4 and I do like the learning remote tool of 2.3.x, I am more interested in getting rewind working properly when running files via nitoTV (which is what I do roughly 60% of the time). So whichever OS gives me a rewind that works without rebooting the Finder is where my ATV will go...

As far as 1.x goes, weren't there more things installed when it came to networking? To get AFS to work in 2.x I had to do a smart install from nitoTV with a very strange hybrid of a restore from 1.x and the Tiger upgrade dmg.

ls

1.0 had a lot of files in place that were needed or things such as afp, it didnt make the functionality of afp any different than it is in 2.x versions though. as far as rewinding is concerned im pretty sure that apple bug goes back to 2.1 and probably even earlier. i stayed on 2.1 for a very long time and definitely experienced it, theres really nothing that can be done short of apple fixing the bug on their end, which there is no real motivation on their part to do it.

All AppleTVs contain the exact same hardware (ignoring disks) except for the wifi card. The wifi card has changed at least twice in the shipping hardware. Running an AppleTV OS prio to what shipped on it could walk into a kext bug where the kernel on a 1.x will panic if the wifi card is the latter ones.

So running 1.x on a factory 2.x might/might not work without tweaks. The tweak is to use the mach_kernel from 2.2 with the 1.x dmg. Generally it is recommended to match mach_kernels and dmgs but this seems to be ok.