Atari 815 Dual Disk Drive – is a dual-disk, single-sided, double-density drive consisting of two 5.25-inch floppy disk drives and a microprocessor for control. The system records data using double-density modified frequency modulation (MFM) at 256-byte intervals. It was the first Atari device to support a recording density of 180 KB per disk (double that of the 810). Internally, it utilized two drive Tandon (TM-100 model).

Released in limited quantities in 1980, it was intended to be the flagship solution for the Atari 400/800 computers, but was ultimately canceled.