Enhanced IDE (Enhanced IDE, EIDE for short) is the new interface introduced by Western Digital Corporation after improving the shortcomings of the traditional IDE interface. The Enhanced IDE uses the Extended CHS (Cylinder-Head-Sector) or LBA (Logical Block Addressing) addressing method to break the capacity limit of 528MB. Now we can successfully use the IDE hard disk with a capacity of several tens of gigabytes. In terms of transmission speed, the Enhanced IDE can currently achieve a maximum transfer speed of up to 100 MB/sec (Ultra ATA/100) due to continuous improvements in technology.