Glad to share Onda V820w Dual OS_32GB newest firmwares, which include dual os bios, flash tool and method. Please click all these links to download: Onda V820w DualOS_32GB Firmware Part1, Part2, Part3, Part4. (Note: The inside android bios is only for V1 version, and the windows bios is for V1, V3 versions.)
This android bios is only for V3 version: V820W Dual OS_Android_V3 Firmware.
Attention matters: If you need to flash the bios, please flash as your tablet corresponding version; wrong bios will cause flash failure. When decompressing, select all 4 packages together, then decompress simultaneously. Don’t decompress one by one, it will cause some files lost.
Have a nice day!