What Does Cable Select Mode for a Hard Drive Do?
Other People Are Reading
-
IDE Hard Drive Selection Choices
-
When IDE drives were originally introduced, there was a need to manually configure each drive, using a jumper to short two clearly marked pins, to designate each individual drive as either a "Master" or a "Slave" on the drive channel. Each channel had a limit of two IDE devices per channel, with almost all computers being provided with two channels.
This jumper setting specifically pertained to installing multiple IDE hard drives, CD-ROM or DVD drives, as well as anything other device that connects to the 40 pin IDE interface found on the motherboard.
If the drives on any channel were incorrectly set (as in both drives being set to Master or Slave), neither drive would be recognized when the computer automatically searched for the drives during the boot process. Additionally, this jumper setting procedure added more time to the assembly of any system being built, which added to the cost of each system marginally.
The Cable Select Mode
-
To utilize the Cable Select mode, an 80 pin cable must be used and each device on the channel must have its jumper set to the Cable Select mode for the Master/Slave mode to be automatically selected. Once these steps are completed, the position of the drive on the cable chain will determine whether the drive is the Master or Slave. Using Cable Select simplifies the installation of any IDE device and prevents mistakes in configuration from occurring.
It is possible to modify a 40 pin IDE ribbon cable by cutting a section of wire out of the 28th wire in the cable, but this is something that should probably only be done in emergency situations when there is no other option available. Otherwise, it is recommended that each individual drive be hand-set, using the jumper to short the Master drive and the Slave drive, with the boot hard drive always being set up as the Master on the drive controller channel.
-
Type of IDE Devices Supporting Cable Select
-
It is important to clarify that the Cable Select technology only pertains to what is known as ATA and PATA style drives and holds true for the entire product line, regardless of the speed designation. While the latest addition of the IDE family, SATA drives, are technically considered to be IDE drives, they do not use the 40 pin IDE interface, and there is no need to set a SATA drive as a Master of Slave drive using a jumper.
-
