Before applying Update 9, verify the PCB revision, back up the original firmware (using sonoflash --read ), and ensure your Grundig Sonoclock 890 has the external ESP8266 mod — otherwise the “web” features will be non-functional.
Data Cash US Grundig Sonoclock 890 Web Firmware Update 9 – A Deep Technical Analysis Data Cash US Grundig Sonoclock 890 Web Firmware Update 9
The subject line “Data Cash US Grundig Sonoclock 890 Web Firmware Update 9” is either a brilliantly crafted piece of alternate-reality tech archiving or a genuine, niche, open-hardware project. It exemplifies how dedicated enthusiasts can breathe web-era functionality into late-20th-century electronics, transcending the original manufacturer’s intentions. Before applying Update 9, verify the PCB revision,
