: Supports hardware revisions C3 through C12 (units made from 2005 to October 2013).
The consensus on forums like and r/RCD_330 (which also discusses RNS units) is that Josi Work 5238 is one of the most reliable custom firmwares for older RNS 510 units that cannot officially run anything beyond 4020/4120. Users report: rns 510 firmware 5238 josi work
The , specifically the modified version by Josi , is a popular unofficial software update for Volkswagen, Skoda, and Seat head units. It is widely used because it can be installed on almost any RNS 510 hardware revision produced between 2005 and October 2013 (Hardware C3–C12) without needing intermediate updates . Key Features of Firmware 5238 (Josi Edition) : Supports hardware revisions C3 through C12 (units
If you want documentation of what does, check: specifically the modified version by Josi