ATA(IDE / ATA) Integrated electronics / AT attachment Interface

Synonyms

ATA, ATA / ATAPI, EIDE, ATA-2, ATA-3, and Ultra DMA.

IDE Overview

IDE is the interface for hard disk and most popular so far. The evolution of IDE changed the dimensions of hard disk performance. It not only increased the performance but decreased cost as well. The hard disk was just a hard card that was physically kept on a controller. Such hard disks mounted on a controller were plugged into the ISA slots. A great deal of problems such as weight, size, expansion slot issues, complexity, cooling and speed were associated with them. The official name of IDE is ATA (Advanced Technology Attachment).

IDE /ATA Classes

IDE Interface not only supports hard disks but also other storage devices such CD-ROMs. There are basically two classes of IDE Interface. Parallel IDE / ATA
Serial IDE / ATA

PARALLEL IDE / ATA

40-pin connectors are attached to the ribbon cable. Typically one cable contains 2-3 connectors. Data Bus width that is the bits that the cable transfers simultaneously is 16. Early versions of IDE contain 40 wires. But now 80-wire versions are available. So they are even faster and efficient. When two hard disks are attached to the connector, computer BIOS reads one as master and other as slave.

Parallel IDE / ATA Issues

One big issue associated with parallel IDE is the length of ribbon cable. The specifications allow the cable length of 18 inches or 46 cm. So it becomes necessary to use the cable internally. One cannot attach large number of devices inside. Moreover to store greater devices externally length should be greater. The software, BIOS settings or OS settings allows configuring master and slaving settings.

PARALLEL ATA Versions

ATA - 1

ATA-1 was the first version that defined an interface. ATA-1 supports 2-hard disk with master and compatibility. Also allows Three PIO modes (mode 0, 1, and 2) and two DMA modes with mode 0,1 and 2 single work and with only mode 0 multiword.

ATA – 2

ATA – 2 was the improvement over ATA-1. It added more functionality to ATA-1 specifications. These include five PIO modes with mode 4 and 5. Multiword support for DMA mode 2 and 3. It added commands to logical block addressing and block transfer. Also added the command as Identity drive. This command displays the information about hard disk.

ATA – 3

Next version in ATA technology was ATA – 3. Obviously it was an enhancement over ATA – 3. It brought new three features to the interface. ATA – 3 defined an improved cable standard for higher speed and improved performance. It brought reliability feature by introducing SMART (self monitoring analysis and reporting technology). The security feature allowed the devices to be password protected.

ATA Packet Interface (ATAPI)

ATAPI supported only hard disks when it first came but with the introduction ATAPI protocol it supported other devices as well.

ATA / ATAPI – 4

Sure it was a great advancement over simple ATAs. Including other features it added number of cool features to the interface. It supported Ultra DMA modes mode 0, 1, and 2, very high-speed modes. It also supported 80-connector IDE cable, CRC cycling redundancy check for error correction. Advanced commands related to the protocols monitoring and handling were also included.