In this article, you will learn to install and troubleshoot IDE devices. First, you’ll be given an overview of IDE devices and some of their features, and then you’ll be shown a number of different configurations for installing IDE devices into a computer system.

IDE overview

The hard drive controller is responsible for converting signals made by the system CPU to signals that the hard disk can understand. These signals include instructions on where to find data and how to get there. The hard disk would perform its task and any data that needed to be returned would be sent to the controller from the hard disk. The controller would then convert the signals from the hard disk to signals that the system could understand.

In the past, the controller was found on an expansion card in the computer system, which then had ribbon cables going from the card to the drives. The goal of IDE was to make the installation of hard disks easier by including the controller on the hard disk, which is where the name comes from: Integrated Drive Electronics (IDE). Today, controllers are integrated into the drive itself, meaning the drive is its own boss. There are also controllers on the motherboard—two perhaps (the primary IDE controller and the secondary controller).

Originally, IDE was only available in the flavor of hard drives, and the hard drives had a maximum capacity of about 528MB. Another important limitation with IDE is that there could only be two devices in a chain. SCSI is stronger in that respect: it supports at least eight devices in a chain.

IDE devices have a transfer rate of about 10Mbps and may have cache on the drive itself. The cache memory is a small amount of memory for storing data that is used frequently to increase drive performance. Due to its limitations, IDE has been replaced by EIDE (Extended Integrated Drive Electronics). EIDE devices have a transfer rate of about 16Mbps. Four devices are now allowed in an EIDE chain, with a greater variety available. For example, you may now add CD-ROMs and even zip drives to the EIDE chain. Note that the capacity of the drives has been dramatically increased to about 40GB!

IDE Versus EIDE

Characteristic        IDE                EIDE
Size                  528MB              40GB and higher
Devices in Chain      2                  4
Transfer Rate         10Mbps             16Mbps
Types of Devices      Hard drives        Hard drives, CD-ROMs

Installing IDE devices

This article will show you the steps to take when installing an IDE device. Because all hard drives are different, only the most popular solutions for installing hard drives will be presented. First, you want to open up the casing of the computer and locate an empty bay to place or mount the new hard disk into. If you are removing the old hard drive, you will be able to use the same bay. However, if you are adding an additional hard drive, you will have to find an empty bay and mount the drive in place.

Cabling

Once you have mounted the drive in place, you will have to take a 40-wire IDE ribbon cable and connect it to the controller on the motherboard and the controller on the hard disk.

One of the wires (Wire 1) on the IDE ribbon cable is a different color than the others; usually, it’s red, but it may be blue. Wire 1 must be placed over Pin 1 when connecting the ribbon cable to the hard drive and motherboard—a procedure known as the Pin 1 rule.

The big question is: how do you know which pin is Pin 1 when looking at the hard disk controller or the motherboard controller? Hopefully, the manufacturer has indicated Pin 1 by placing a small “1” in the place where Pin 1 should be. If you look at the controller on the hard disk or on the motherboard, and then at either end of the controllers, you may see a small “1” on one of the controller ends. That’s where you need to place Wire 1 when connecting the ribbon cable.

Sometimes the manufacturer may not have enough space to indicate Pin 1, so they choose to do the opposite, which is to indicate Pin 40. This method gives you the same information, though: if you know what side Pin 40 is on, you know that Pin 1 is on the opposite side.

Once you have connected the IDE ribbon cable, you want to give the hard disk power from the power supply so that you can run the motor in the drive. Oftentimes, people forget this step.

Master/slave

If you are installing multiple IDE devices, you are creating an IDE chain. The chain will be made up of one 40-wire IDE ribbon cable and two drives connected to that IDE ribbon cable. The ribbon cable will be connected to the controller on the motherboard.

Once you have the two drives connected together, you will need to configure the drives into a master/slave configuration. Why this type of configuration? Because each drive has a built-in controller, which makes it act like its own boss. When setting up a multi-drive system, you have two drives, each with a controller that can potentially send and receive signals to the processor. To save confusion, one of the drives is designated the master. The master drive will receive all signals from the processor and send back any data on behalf of both drives. The other drive is designated the slave. The slave drive will pass any information it wants to send to the processor up to the master, which will then forward that information to the processor.

Once you have the drives connected to the ribbon cable, you will have to configure the jumper settings on the drives to tell the system who the master is and who the slave is. The idea of the procedure is similar for all drives, but the actual jumper setting may be different for each type of drive.

Many of today’s drives have three jumpers that can be set to configure a master and a slave. One jumper setting designates the drive as a master (sometimes abbreviated “DS” for “drive select”), one jumper setting sets it as a slave (sometimes abbreviated “SP” for “slave present”), and a third jumper setting enables “cable select,” or “CS” for short. Cable select would set the master and slave automatically, based off the order of the devices on the cable. This article discusses typical configuration examples of master and slave devices. Typically, you would set the DS jumper on the drive you would like as the master, and then set SP on the drive you would like as the slave

Sometimes the jumpers may be labeled simply “Master” and sometimes they may be labeled “Slave.” These drives are usually pretty straightforward to configure. You place the jumper on the master setting for the drive you would like as the master, and you place the jumper on the slave setting for the drive you would like to configure as the slave drive.

Unfortunately, all drives are different. You may find that you do not have jumpers labeled DS, SP, and CS. You will have to check the documentation for the drive to see how the manufacturer would like the master and slave configured.

Many times, configuring your drives in a master/slave setup may not be as easy as discussed in these pages. What do you do when you cannot see a specific master or slave jumper setting? Many drives will place documentation on the back of the drive telling you how to configure the drive for master and slave setups. Unfortunately, this was not the case on a drive I had to configure in the office one day. So I went to the manufacturer’s Web site and found out that this drive had a jumper labeled J20; the Web site documentation stated that if the drive was the only drive or was the master in a dual drive configuration, the jumper (J20) should be set. If the drive was the slave in the dual drive configuration, the jumper (J20) should be removed.

Today you are probably working with EIDE drives, which—as mentioned earlier— support up to four devices instead of two. In these systems, there are two controllers on the motherboard: the primary controller and the secondary controller. Each controller can have two devices, for a total of four devices. Typically, the devices can be either hard drives or CD-ROM devices. The steps are the same to master and slave a hard disk and a CD-ROM, but the CD-ROM will probably always be the slave (or may be the master device on the secondary controller). In today’s systems you may encounter different types of devices that are IDE devices, such as hard drives, CD-ROMs, and zip drives.

After configuring the jumpers on the drive, you will power on the system. The computer should recognize that there is an additional drive and take you into the CMOS setup program. Your system should have the drive written into CMOS. You will just have to save the change and exit out of the CMOS setup program.