Removing the Old Hard Drive

Before you disconnect anything, take a good look at the way the IDE ribbon cable is connected. Note the red stripe on one side of the IDE ribbon cable, that indicates it is connected to Pin 1 on the motherboard on one end and to Pin 1 on the hard drive on the other end. Remember which connector on the IDE ribbon is connected. Disconnect the IDE ribbon and the power connector and move them aside such that you won’t forget how it was connected. Remove the screws holding the drive in the mounting bay being careful not to drop them into the guts of the machine. The best way to do this is to use one hand to operate the screwdriver, one hand to hold the screw so it won’t drop, and one hand to prevent the hard drive from falling when you remove the last screws. Set the screws somewhere so they don’t get knocked away sending you groping for them on the floor. Remove the old hard drive.

Installing the New Hard Drive

First, you must determine the jumper configuration of the new hard drive. Depending on the make and model, to use the drive as a single drive, it might require NO JUMPERS or may require it to be jumpered as Master. Consult the documentation, the manufacturer’s Web site or the label on the drive for this information. In most cases the drive will not work properly if incorrectly jumpered. Symptoms range from the drive not being recognized at all to intermittent drive controller failure messages during POST. There are usually three jumper positions, Master, Slave and Cable Select. Some computers determine master/slave relationships based on how the drive is connected to the IDE ribbon cable, but do not use this setting unless specifically instructed to do so. Consult your computer’s documentation. There can also be a jumper position for “Master with Slave” (no, you can leave your whip in the closet) or even a spare position to store a jumper for later use. All I can say is consult any documentation or the label on the drive for the proper jumper setting. It is imperative for proper operation of the drive to set the jumpers correctly. Sometimes you have to turn the drive upside down and look at the printed circuit board for jumper position labels. For example it may say M, S and CS (Master, Slave and Cable Select)

What does Master and Slave mean?

On a normal motherboard there are two IDE controllers, usually called IDE 1 and IDE 2, or Primary and Secondary IDE controller. Each controller can handle up to two IDE devices, e.g. two hard drives, a hard drive and a CD-ROM, etc. meaning you can connect up to 4 IDE devices. Even though each controller can handle two devices, it can only transfer data for one device at a time alternating between the two devices. Therefore it is best if you only have two IDE devices in your system (one hard drive, one CD-ROM) to put each one on a separate controller.

To distinguish the two devices on each controller, you designate one as the Master device, and the other as the Slave device. This is done by setting jumpers (called “jumpering”) in a certain fashion determined by the drive manufacturer and documented usually on a sticker on the drive itself.

The first device on the first IDE controller is called Primary Master.
The second device on the first IDE controller is called Primary Slave.
The first device on the second IDE controller is called Secondary Master.
The second device on the second IDE controller is called Secondary Slave.

Normally, the computer always boots from the primary Master device, unless you have a special SCSI setup or chose to boot from floppy or CD. That’s why it is very important that all devices are given their correct identity by jumpering them correctly.

OK, now that the drive is jumpered correctly, mount the new hard drive in the bay, the same way as the old one. Tighten the screws evenly, but do not over tighten such that the threads get stripped, ok Arnold? Hopefully your new hard drive is the same size and shape (these are things you must consider before purchasing a new hard drive). That spec is referred to as “Form Factor”. For example, most modern hard drives are 3.5 inch form factor with low profile (thickness).


Data Ribbon Cables

Connect the IDE ribbon cable to the new hard drive. The red stripe on the cable must connect to pin 1 on the drive. Look for some kind of marking at the connector on the drive, usually a small number 1, and match it up with the red stripe on the IDE cable. If you can’t find such a marking, a general rule of thumb (but don’t bank on it!) for hard disks and CDROM devices is that the red striped side of the ribbon goes on the side closest to the power connector. As an aside, most floppy drives follow the opposite of this rule. IDE hard drives nowadays, have a missing pin and therefore the IDE ribbon cable connector can only go on one way, because the corresponding hole is filled over with plastic. It is important that you Do Not Force the connector, but line the pins up and press gently but firmly (and straight! do not wiggle it or apply pressure at an angle) with gradually increasing pressure. Then connect the power connector to the new hard drive.

It is recommended practice to connect the cable such that the master device is at the end of the cable, with the slave device on the inner connector. That means you must mount your drives accordingly, so that the cable will reach far enough to connect it in this manner. However, with normal 40 wire IDE ribbon cables (ATA33 or normal PIO) this is not critical. In most cases, you can hook up the cable the way it best fits, according to where the master and slave devices are mounted in the bays. If you’re too lazy, or unable to change how the drives are mounted it is far better to connect the cable in this manner than to severely twist or kink to make the connections. It is also of significance to note, that IDE ribbon cables should be a maximum of 18 inches in length (according to specifications), to minimize attenuation (weakening) of the signal. However, 24 inch ribbon cables are available and should not pose a problem if you need that extra reach.

This does not apply to ATA66 or ATA100 interfaces that use the more sophisticated 80 wire ribbon cables. The connectors on the ribbon cable are color coded, and we must pay careful attention to where they are connected.


  • The blue connector must connect to the interface connector on the motherboard, or ATA66/100 controller card.
  • The black connector must connect to the master device.
  • The grey connector must connect to the slave device (if present)

The devices are jumpered in the same manner, in a Master/Slave relationship or Cable Select can be used if supported (but not a mix of the two on the same cable). It is important to consult the documentation as always, because some drives (e.g. Western Digital) have a separate setting for Standalone Master and Master with Slave. With the ATA66/100 cables, it is more important to pay attention to cable length. Cables longer than 18 inches are not recommended. For ATA66 you may get away with 24 inch cables, but it’s more critical for ATA100.

Now that we have the hardware installed, the next step is to get the BIOS to recognize the drive with the correct parameters.


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