Definitions of Common Integrated Drive Electronics (IDE) Terms (Q262969)
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The information in this article applies to:
Microsoft Windows Millennium Edition
Microsoft Windows 98
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SUMMARY
This article provides a list of common Integrated Drive Electronics (IDE) terms.
MORE INFORMATION
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.
