Hello, can someone explain how this is done? I have the bootloader and the c19 module but don't understand how it all works. My call quality is horrible with the gsm D27. Thanks!

Hey camillo,
start the flash.exe. Then you check the GSM-Box (you want to update the GSM-Module, don't you?) - then you click on browse on the right and search for the txt-file GSM.txt
In case you just received the GSM.bin without any files, it shouldn't be a problem, using another GSM-module-folder (eg "GSM944D27-(use_this!!)-GSM_-_March_version") and overwrite the GSM.bin there. No warranties on that however. I just tried that with this folder - got that in the firmware-package, that can be bought. Yeah 2 $ is much for something, that's supposed to be free, but then again I didn't want to spend hours for searching all files.

Regards
Jens