Hi; Can someone briefly explain to me the difference between an IDE (ATA) and a SCSI device. After having done due diligence with google searches etc., I am still in a quandary. Nothing I read seems to be consistent. Every time I think I have it figured out, I read a reference that calls for or lists IDE devices that I think should be a SCSI reference and vice versa. Even going to the various standards sites doesn't clarify it for me. In fact it makes it more confusing. Therefore, can someone explain, in plain language, how I should use the terms IDE or PATA, and SCSI correctly with regards to a current computer? What specific attribute of a device or bus does each term apply to? Given below are some questions that spring to mind. They may be mis-formed questions and therefore need not be answered, but they may demonstrate where my confusion and misunderstanding are coming into play. e.g. Does IDE refer to the physical device? Or, specifically just to the bus used? Or, to the driver for the device? Or, the type of interface (plug)? Does SCSI refer to a set of protocols used when designing the device? Or, to a specific driver design? Can you have an IDE device without SCSI? Or, can you have a SCSI device without it being IDE? Below, I have listed a few of the sites I have visited with the definitions given to show I have found the history and some attempts at an explanation. I long ago learnt that any manual's reference to IDE or SCSI usually simply meant some reference to my hard drive. I am aware it could also mean my CD or a DVD, but usually it is a reference to a HD. http://en.wikipedia.org/wiki/IDE http://en.wikipedia.org/wiki/Integrated_Drive_Electronics http://en.wikipedia.org/wiki/SCSI Integrated Drive Electronics, a computer hardware bus used primarily for hard drives and optical drives (e.g. CD, DVD) Advanced Technology Attachment (ATA) is a standard interface for connecting storage devices such as hard disks and CD-ROM drives inside personal computers. The standard is maintained by X3/INCITS committee T13. Many synonyms and near-synonyms for ATA exist, including abbreviations such as IDE and ATAPI. Also, with the market introduction of Serial ATA in 2003, the original ATA was retroactively renamed Parallel ATA (PATA). SCSI (Small Computer System Interface) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it can connect a wide range of other devices, including scanners and CD drives. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements. -- Regards Bill
