Back at Google I/O 2014, Google made some huge announcements. In addition to Android 5.0 Lollipop, they also announced Android Wear, Android Auto and Android TV. This was the search giant's second attempt at the living room, with a set-top box (after Chromecast was a success). Everyone in attendance at Google I/O got to go home with the ADT-1 which was powered by an ARM chipset (the NVIDIA Tegra 4 to be exact) while the Nexus Player was an Intel or x86 processor. The ADT-1 was a great developer unit for Android TV to get started ahead of the official release of Android TV. Google hadn't given much attention to the ADT-1 after Google I/O, with its last official update being Android 5.0.2.
However, thanks to developers over at XDA, we now have an Android 6.0 build for the ADT-1 in the form of a Pure Nexus ROM. So those of you with the ADT-1 Android TV set-top box, can flash the update onto the set-top box and have some fun with Android 6.0 Marshmallow. Now, to flash this ROM you will need to have the latest version of TWRP recovery, so you can flash the ROM. The update weighs in at about 182MB. Once you flash the new ROM, you'll get an update for Android 6.0.1 that you can simply install like an OTA on the ADT-1.
There aren't many choices for Android TV right now, only a handful of set-top boxes are currently available. Like the NVIDIA SHIELD TV, the Razer Forge TV and the Nexus Player. The ADT-1 is still a great choice, unfortunately there aren't many out there considering they were only given out to those that attended Google I/O in 2014. The Pure Nexus ROM is a great Christmas present, though, for those with the ADT-1 that want to get to using the ADT-1 on the latest version of Android again. You can hit up the XDA thread which is linked down below to get the update and for instructions on how to flash the ROM onto your ADT-1. It's pretty simple, but it will void your warranty. So just a heads up there.