This was a difficult driver to find so I have made it available on my blog so others in the future don’t have to go through the same hassle of finding it (it’s not even possible to download it from the Atheros website).
The driver is designed for Windows 8.1 32/64bit but I am using it just fine on Windows 10.
Driver version: 10.0.0.308
Driver date: 11/12/2014