IDE (Integrated Drive Electronics)

IDE (Integrated Drive Electronics) is a standard electronic interface used between a computer motherboard's data paths or bus and the computer's disk storage devices. The IDE interface is based on the IBM PC Industry Standard Architecture (ISA) 16-bit bus standard, but it is also used in computers that use other bus standards. IDE was adopted as a standard by the American National Standards Institute (ANSI) in November 1990.

The ANSI name for IDE is Advanced Technology Attachment (ATA), and the ATA standard is one of several related standards maintained by the T10 Committee. In today's computers, the IDE controller is often built into the motherboard. Prior to the IDE drive, controllers were separate external devices so IDE reduced problems associated with storage devices and integrated controllers.

There are two ATA interface types: Parallel ATA (PATA) and Serial ATA (SATA).

ATA standards

ATA-1: This first standard, which was developed by Compaq, Control Data Corp. and Western Digital, used an 8- or 16-bit interface. It instituted the use of a master/slave configuration, and defined multi-Word Direct Memory Access (DMA) mode and Programmed I/O (PIO) modes 0-2. It is now considered obsolete.

ATA-2: Better known as Enhanced IDE (EIDE). EIDE outlined PIO mode 3 and PIO mode 4.

ATA-3: Improved the reliability of high-speed transfers and added Self-Monitoring Analysis and Reporting Technology (SMART).

ATA/ATAPI-4: Increased data transfer rate support to 33 megabytes per second (MBps) -- known as Ultra DMA/33 -- and added the AT Attachment Packet Interface (ATAPI) feature.

AT/ATAPI-5: Supports data transfer rates of up to 66 MBps.

ATA/ATAPI-6: Supports Ultra DMA/100, which lets drives theoretically reach 100 MBps. Also includes Automatic Acoustic Management, which allows drives using this feature to automatically adjust access speed and reduce running noise.