OSF for 860C (for TSDZ2) - why different OSF .bin files?

[GrampaPete]

I assume their must be different 860C versions to necessitate a V12, V13 and V20 .bin files to flash the newest OSF version. Could someone pls explain why there are these 3 files. Thanks

 

[TAPnAR]

I have the same question, I have an older unit from around 2021. Here is a pic of the back of the unit. Not sure what version to use. I am running an older version of OSF.