PC Assembly - Hard drive installation

Hard drives, CD-ROM, DVD-ROM drives and floppy drive

The motherboard usually has two IDE (Integrated Device Electronics) connectors:

  • The first connector is known as the primary device controller;
  • The second is known as the secondary device controller.

Each connector can take two IDE devices connected with a single ribbon cable, making a total of 4 IDE devices (two devices per ribbon cable connected to the motherboard). To overcome this limit of 4 IDE devices, additional devices can be connected using an IDE controller expansion card or a SCSI controller.

Where two devices are connected to the same IDE ribbon cable (the cable which connects one or two IDE devices to the motherboard), we must tell the computer which of the two has priority, or more precisely which is the master and which is the slave, abbreviated to SL. To do this, the devices must be configured using jumpers located at the rear of the device (beside the IDE connector). There is normally a small diagram on the device depicting the jumper positions for master (M) or slave (SL).

Note that you may also see the abbreviation CS (for cable select) which means that the master and slave disks are determined automatically if both disks have this option and it is supported by the motherboard.

It is also recommended to connect devices of the same type using the same ribbon cable as the bus transfer speed adapts to the slowest device on the cable. It is therefore recommended to put disks drives on one cable and CD-ROM and CD burners on the second (a CD burner is installed in exactly the same way as a CD-ROM drive).

As we have seen, there are 2 IDE channels, where a maximum of two disks can be connected to each IDE channel.

By default the computer will boot up using the first hard drive located on the primary IDE channel. Order of priority is as follows:

  • IDE1 - Master,
  • IDE1 - Slave,
  • IDE2 - Master,
  • IDE2 - Slave.

Recommended configuration is as follows:

master disk      
master disk slave disk    
master disk slave disk master disk  
master disk slave disk master disk slave disk
master disk   master CD-ROM  
master disk slave disk master CD-ROM  
master disk   master CD-ROM slave CD-ROM
master disk slave disk master disk slave CD-ROM
master disk slave disk master CD-ROM slave CD-ROM

When connecting IDE devices it is important to check that the red line on the ribbon cable is lined up with pin 1.

  • on the motherboard:

    Connecting an IDE ribbon cable to the motherboard

  • on the hard drive(s) (usually beside the power connector):

    Connecting a hard drive to an IDE ribbon cable

Other IDE devices (CD-ROM / DVD-ROM drives or burners) are connected in the same way.

For further information check the IDE/ATA bus section.

Serial ATA

If the motherboard has Serial ATA (SATA) connectors, it is recommended you buy hard disks with this interface as it is much faster than the IDE interface. Serial ATA cables are thinner and allow for better air circulation.

Serial ATA drive installation is very simple: just connect the hard drive to the Serial ATA connector with the cable that comes with the motherboard. A BIOS setting often needs to be configured to activate the SATA connector.

For further information check the serial ATA section.

SCSI Drives

For SCSI hard drives or CD-ROM drives a SCSI controller must be installed first, or use the integrated controller on the motherboard if necessary.

Next the IDs must be assigned to each device in the chain. Jumpers on the disks can be used to set the number.

For further information check the SCSI section.

Floppy disk drives

Floppy disk drives (FDC, for Floppy Disk Controller) are connected using a ribbon cable, which is narrower than an IDE cable, and is connected to the floppy disk connector on the motherboard.

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