The latest OS version for the A-Station is OS2.1.02.
To check to see which version of OS is installed in an A-Station, power the A-Station up while holding down the number 3 button.
The screen will show 2.1 followed by 2 if OS2.1.02 is already installed.
If it is not, this OS can be download and installed using the files from the download section of this website.