While you can't download an update file to a USB stick, the D-808 has undergone several over the years that change how the radio behaves. 🛠️ Identifying Your Version
While you cannot update the software yourself, the manufacturer has released several hardware revisions over the years with internal "factory firmware" changes. How to Identify Your Version
The D-808 is praised for its extensive filter options (up to seven for AM/FM/AIR and six for SSB), which are hard-coded and offer excellent selectivity for a radio in this price bracket. Audio "Pops":
XHDATA silently changed the microcontroller inside the radio during production.