Definitions of Common Integrated Drive Electronics (IDE) Terms (262969)

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• Integrated Drive Electronics: A generic term term that can be applied to any drive with an integrated controller.
• AT Attachment (ATA): The specification or standard that an IDE device should conform to for connecting to a computer.
• Master/Slave: A method of configuring which IDE device is device 0 and device 1. This makes use of jumpers on the individual device. It is necessary for the devices to respond only to commands that are intended for them and ignore commands for other devices.
• Cable Select (CSEL): A method of determining which IDE device is device 0 and device 1 by their position on the IDE cable. No jumpers have to be set on the IDE device. This method requires a specialized cable and is generally only used with some ATA-66 devices.
• Ultra ATA (Ultra DMA, ATA-33, DMA-33: A newer ATA standard that supports multiword DMA mode 3 running at 33.3 megabytes per second (MB/s). This includes special error detection and correction logic (CRC) to support this by using a standard IDE cable.
• ATA packet Interface (ATAPI): An extension to the original ATA standard that adds support for connecting devices other than hard disks.
• Programmed Input/Output (PIO): A method of ATA transfer that is controlled by the central processing unit (CPU). There are 6 PIO modes (0 - 5) supporting speeds from 1.67 Mbps to 22 Mbps.
• Direct Memory Access (DMA): A method of ATA transfer that makes use of DMA controller to bypass the CPU. Also supports bursting and bus-mastering to achieve higher transfer rates. There are 3 overall standards that are further divided: Single Word (mode 0 - mode 2) supporting speeds from 1.04 Mbps to 4.14 Mbps, Multiple Word (mode 0 - mode 2) supporting speeds from 4.17 Mbps to 16.7 Mbps, and Synchronous DMA (mode 0 - mode 4) supporting speeds from 16.6 Mbps to 66.6 Mbps.
• Enhanced IDE (EIDE): This is not a separate standard but a description of any device that supports ATA-2 and ATAPI.
• ATA-2: An update to the original ATA standard added support for PIO modes 3, multiword DMA modes 1, block transfers, LBA and some additional commands.
• ATA-3: An update to ATA-2 that adds PIO mode 4, multi-word DMA mode 2 and S.M.A.R.T.
• ATA-4: An update to ATA-3 that adds synchronous DMA modes 0,1 and 2 that permits transfers of up to 33.3 Mbps.
• ATA-5: An update to ATA-4 that adds Synchronous DMA modes 3 and 4 support transfer rates of up to 66 Mbps. It also adds enhanced LBA support for larger drives.
• Block mode: This supports multiple read/write commands in a single operation and reduces interrupts to the CPU.
• Logical Block Addressing (LBA): A way of addressing the hard disk by assigning a number to each physical sector. When combined with translation, this provides support for drives up to 8 gigabytes.
• Cylinder/Head/Sector (CHS): A way of addressing the drive that is based on the cylinder, head and sector that is being read. Only supports 504 megabytes without some type of extended translation.