There have been two releases of “Experimental” firmware which are used on the Retevis/TYT range such as the RT3/MD380, RT8/MD390 and RT82/MD2017. This firmware adds functionality to the radios and allows for a larger number of entries from the DMR ID database to be uploaded to the radio by altering the memory allocation.
One of the releases was a Linux based software that required a Raspberry Pi to install and the othr requires a Windows based computer.
Below are details on the Windows version.
RT3/MD380 & RT8/MD390
It’s vital to note that newer radios with factory firmware v14 and higher are not supported. This is due to TYT making the radios non-compatible with the experimental firmware and the creator (Ty Weaver KG5RKI with assistance from Travis Goodspeed KK4VCZ) will not be recreating the firmware. Therefore its best to buy an older/secondhand model should you wish to use this firmware.
Here is some documentation on this firmware – http://www.miklor.com/DMR/pdf/TyMD380Toolz.pdf
RT82 & MD2017
This firmware (also created by Ty Weaver KG5RKI) is available directly from the Retevis website – https://www.retevis.com/resources-center/