The stock DM-1801 firmware is functional but basic. It is derived from the same codebase as the Radioddity GD-77, but with slight modifications for the DM-1801’s larger, high-contrast LCD and more rugged casing. The stock firmware version typically ships as V1.0.0 or V1.2.5 (depending on manufacturing date).
Flashing custom firmware . However, you can re-flash the stock DM-1801 firmware (available from Radioddity support) before sending the radio for repair. No permanent hardware mod is required. dm-1801 firmware