Resources

Apple II DuoDisk symbol is A9M0108. Information how to connect this drive to Apple II Disk Controller (with two 20 pin onboard connectors) are available on Apple Disk 5.25 page.

Wiki
Apple Floppy Drives
Owner’s Manual
Cable Pinouts
Apple DOS Manuals
Duodisk Technical Procedures

Compare with other external Apple drives: Apple Disk 5.25, Apple Disk II, Apple IIc Disk, Apple Disk ///, Macintosh 400K Drive, Apple 3.5 Drive.

Internals

Disk Mechanism

Both drives use the same drive mechanism.

Analog Board

Reassembly

Cable

One side of this cable has the surrounding metal screen broken, but the cable works just fine without it.