SCSI evolved from the Shugart Associates Standard Interface (SASI), which Shugart Associates, an early hard disk manufacturer, developed in 1981 in conjunction with NCR.
By the time ATA/133 (also known as UltraDMA 133) – expected to be the final generation of Parallel ATA interface before the industry completes its transition to Serial ATA – was announced in mid-2001, throughput had been increased to 133 MBps. The first version, introduced in 1981 had a throughput of 4 MBps. The standard has evolved considerably over the years. Hewlett-Packard and IBM each developed proprietary parallel interfaces, but the two that were to survive were ATA and SCSI.ĪTA (AT Attachment) is an interface specification which incorporates the IDE (Integrated Drive Electronics) concept originally proposed by Western Digital and Compaq in 1986 to overcome the performance limitations of earlier subsystem standards.ĪTA is extremely inexpensive to manufacture, and has become the most common storage interface on personal computers. Although it was technically feasible to build fast serial interfaces, it wasn’t practical because the high-speed controller would cost more than the 8MHz PC it would go into.Įngineers seeking a cost-effective alternative to serial began to use parallel connections. Early storage interfaces were essentially serial connections with clock speeds limited by the relatively slow controller chips. The ATA and SCSI interfaces used to connect hard drives to your PC each has a long history. The tutorial also provides a historical perspective on the evolution of both of the hard disk interface technologies – EIDE/ATA and SCSI – and of the various capacity barriers overcome over the years. This tutorial will take you through the steps involved in installing a second ATA hard disk drive – covering each of the following: