The Amdek AMDC I is a rare third-party floppy disk drive released by the American company Amdek Corporation (originally Leedex) in 1983. Its main feature was the use of a 3-inch microfloppy disk format, unusual for the time, instead of the standard 5.25-inch disks. The microfloppy disks were 3-inch hard disk cartridges (Hitachi microfloppy standard) that could be used from both sides (by flipping them over). Single-sided recording in Double Density mode provided approximately 180 KB per side.

The device also featured a built-in parallel printer port (Centronics), a unique advantage over the original Atari 810. The drive contained its own motherboard with firmware (EPROM), allowing it to process I/O commands independently of the computer's processor.

Despite its compact size and advanced features, the 3-inch floppy disk format lost the standards war to Sony's 3.5-inch floppy disks (which Apple chose for the Macintosh). Due to the high price of the media and the drive itself ($550 at launch), the Amdek AMDC I remained an exotic item and is today a valuable trophy for collectors.