Convert bmp to duo Online: bmp2duo
You can use Tom's Editor to easily convert images from
Microsoft Windows bitmap .BMP to DU1, DUO .DUO.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Format created by Microsoft for their Windows and OS/2 operating systems. Images can be compressed or not.
DU1, DUO is an image format with extension DUO.