PC Hardware in a Nutshell, 3rd Edition

Chapter 13. Hard Disk Interfaces

The hard disk interface defines the physical and logical means by which the hard disk connects to the PC. In the 1980s, the most popular disk interfaces were ST506/412 and ESDI, which are now obsolete. These old drives use two ribbon cables (a 20-pin data cable and a 34-pin control cable) versus the single-ribbon cable used by modern drives. Finding one of these old dual-cable drives in a PC by itself establishes that that computer is too old to be upgraded economically. A modern PC uses one or more of the following hard disk interfaces:

Integrated Drive Electronics (IDE)

IDE (pronounced as individual letters) was by far the most common hard disk interface used in PCs from the early 1990s through 2003. IDE is officially designated ATA, but is now often informally called Parallel ATA or PATA, to differentiate it from the new Serial ATA (SATA) interface. IDE is still used in new systems, although it is being superceded by SATA.

Serial ATA (SATA)

Serial ATA (SATA) is a new technology that will ultimately replace parallel IDE/ATA. SATA has several advantages over PATA, including superior cabling and connectors, higher bandwidth, and greater reliability. Although SATA and PATA are incompatible at the physical and electrical levels, adapters are readily available that allow SATA drives to be connected to PATA interfaces and vice versa. SATA is fully compatible with PATA at the software level, which means that the ATA drivers supplied with current ...