micro- +"Ž drive
An earlier, ultra-miniature hard disk from Hitachi Global Systems. The Microdrive was introduced by IBM in 1998 and acquired by Hitachi in 2002. It contained a single disk platter the size of an American quarter, and starting out at 170MB of storage, it evolved to 8GB by 2006. Using one or two giant magnetoresistive (GMR) heads, the entire mechanism was built into a Type II CompactFlash card. See magnetoresistance and CompactFlash. Size Matters Because the tiny actuator had 50 times less inertia than one used in a regular disk drive, it could ramp up to full speed in half a second. As a result, the drive could stop spinning when data were not being accessed, conserving power in handheld devices. By the mid-2000s, CompactFlash flash memory cards began to exceed the Microdrive's capacity. See Kittyhawk and actuator.