There are a few versions of experimental firmware available on the market, most which is not so much experimental anymore as they have been around quite some time and are fairly stable. It adds more features such as a last heard, backlight settings, bar graph for your audio and manual dial for talk groups.
Currently the firmware is available for the TYT MD380/MD390 and Retevis RT3/RT8 radios however it’s believed that there is work in progress on tools for the Retevis RT82/TYT MD-2017 and possibly other radios.
Note that the radio must be in DFU mode in order to do the Firmware update then in standard operating mode to update the DMR ID user database.
One of the first releases was the Travis Goodspeed MD380 Tools which works on Linux so not the easiest for everyone. Many Raspberry Pi image files contain a file of radio related tools including these tools. There are 3 files, one to download the latest tools, one to upload the tools then the last to update the user database. There is an instruction file included. This is available via GITHub – https://github.com/travisgoodspeed/md380tools
Then there is the “newer” KG5RKI Tytera Flash Tool v1.08 which has become more popular. This is a Windows based program that is standalone (does not require an installation). You only need to extract the zipped files into a folder on your C Drive and run the exe file. Only the Firmware and UserDB sections are currently in use. To update the Firmware, put the radio into DFU mode, download the GPS or NON-GPS version. Once downloaded, press flash and wait for it to upload. To update the User Database, press the Download Update button. Once downloaded, press Flash.
There is a User Database program for the Moonraker HT-500D / TYT MD-2017 / Retevis RT82 which is available via the following link – http://www.retevis.com/rt82-resources/
This can also be used on the TYT MD-9600 / Retevis RT90 however it’s not the easiest to read due to the wide screen on the mobile radios. There is a bit of software which converts the userdb.bin file which is used on the handhelds and reformats it to make it easier to read – the instructions can be downloaded here – http://df7pn.darc.de/files/MD9600Userdb_Usersguide.pdf and the program can be downloaded via this link – http://df7pn.darc.de/files/MD9600Userdb.zip