Microdrive was a miniature hard-drive format designed to fit in a CompactFlash Type II slot and was launched by IBM in 1999.
Initial capacity was 170 MB, but this eventually increased to 8 GB.
Other manufacturers have released similar drives, usually referred to as 1-inch drives or CompactFlash drives due to trademark issues.
Microdrives were also embedded into devices such as certain iPods and other music devices, and PDAs. Because they are mechanical devices, they are more sensitive to shock and temperature changes than flash-based media,
As of 2011, Microdrives are viewed as obsolete, having been eclipsed by solid-state flash media in storage capacity, durability, physical size, and price.