PHOTO:  HD

VIDEOS:  hard drive install side, HD zoom in angle, HD install side - a bit closer, HD mounting bracket install

The hard drive stores programs ("software") and data which are saved and (re)used when the machine is running.  Programs contain directions that tell the CPU and the rest of the computer what to do.  If you accidentally erase part or all of a program on your hard drive, that program will not function properly, or at all.  Without the hard drive and the programs on it, the computer would have nothing to do. 

The original IBM hard disk held 10 Megs (10 million characters) of information.  Most new systems now come with hard drives measured in "Gigabytes", or BILLIONS of bytes of storage space.  One gigabyte is equal to 1000 megabytes.  A 30gig hard drive holds 30,000 Megs, or approximately 30 billion characters of information (enough to hold a library full of text!!!).  To be clear, hard drives smaller than 1 gig (not used very often in modern machines) are measured in Megs:  a 540Meg hard drive is really .54 gigs (about half a gigabyte; gigabyte=1000 Megs).

Hard drive performance is measured in RPM speed and "ATA" data transfer speed.  5400 RPM drives are less expensive than 7200 RPM drives, but since they spin slower, their performance is slightly slower all around.  Drives also have ATA data path ratings such as ATA33, ATA66, and ATA100.  The higher the number, the more information the drive can send to the motherboard per second, and the faster its performance.  If you want to make use of fast ATA drive speeds, you must make sure that your motherboard has support for that standard (i.e., if you want to make use of the fast transfer speed offered by an ATA100 drive, you must make sure that your motherboard supports ATA100 transfer speeds.  The drive will work otherwise - it just won't work as fast).  Hard drive speed plays a very important role in overall system speed.  If you want the quickest machine possible using an IDE drive, purchase a 7200 RPM ATA 100 drive, and make sure that your motherboard and cables have support for ATA 100 data transfer.

Most modern hard drives are made with an "IDE" connector that attaches, via a flat ribbon cable, to the IDE pin connectors on the motherboard.  IDE ribbon cables are also used to connect CD-ROM, tape, and ZIP drives to the MB.  Each IDE cable typically has connectors for 2 separate IDE devices, called a "Master" and a "Slave" on the cable.  Cables are marked with a stripe along one edge, which should be aligned with the pin marked "1" on the motherboard and the hard drive.  Motherboards typically contain 2 IDE connectors - labeled as "primary" and "secondary", each supporting two cable connections, so the typical computer system can support up to 4 IDE devices. 

PHOTOS:  floppy and HD with cables (HD is on the right hand side), HD IDE cable connect CLOSE UP

VIDEOS:  IDE Connectors on MB, IDE cable, stripe, being plugged into mb, IDE cable into HD, floppy and hard drive cables (IDE cable is on the right hand side), Dual IDE plugged in, with closeup, IDE double end cable into MB and HD, IDE double to CD ROM and HD + power connectors (This video shows CD-ROM connections and power connections - more on CD-ROMs later), CD ROM + HD on dual IDE in AT Tower

Most computers have one hard drive, which is set up by default as the PRIMARY MASTER IDE device.  Jumper pins on the back of the hard drive determine its master/slave settings.  The small pieces of metal and plastic are used to close connections between jumper pins.  There is typically a diagram or directions on the hard drive which show how to set it as master or slave (a third selection called "cable select" is usually available, but this option is not suggested).  If your computer has a DVD, CD-ROM, or CD-RW drive, it should be set as slave, and attached to the other connector on the primary IDE cable.  The secondary IDE cable is available for additional IDE drives (i.e., optional CD drives, hard drives, zip drives, etc …)  The physical installation of IDE drives is completed by mounting the drive in one of the 3.5" or 5.25" bays of the case, setting the jumpers, attaching the IDE cable, and plugging in a power cable from the case power supply:

VIDEOS:  HD jumper set, hd jumper install, DVD jumper set, DVD jumper install, IDE double to CD ROM and HD + power connectors, CD ROM + HD power cables (with closeup), CD ROM + HD on dual IDE cables (This video shows HD and CD-ROM connected to two SEPERATE cables.  In this scenario, both drives would be set up as MASTER or SINGLE)

SCSI:  A second standard, called "SCSI" (pronounced "scuzzy"), is often added to a computer with an expansion card that plugs into a PCI or ISA bus slot.  SCSI drives are typically faster than the best IDE drives, so they are often used in powerful machines made for multimedia editing, high end games, and fast data processing.  The fastest SCSI drives rotate at 10,000 RPM - much faster than IDE drives (they are also much more expensive).

There are no Master or Slave settings on SCSI devices.  There are device ID #'s instead - SCSI cables can hold up to 7 devices, each with a different number (there typically are jumpers or switch settings which set the device number on each SCSI drive).  SCSI cables can be attached as devices on the main SCSI cable, allowing up to 49 devices per SCSI connector!  There are many varieties and generations of SCSI (SCSI I, SCSI II, SCSI III, Ultra, Ultra Wide…) - each faster (and more expensive) than its predecessor.  If you intend to build a machine exclusively for video editing or sound processing, SCSI should be a consideration.   If you do install a SCSI system, the expansion card, hard drive, and cabling should all be of the same type - talk with your hardware vendor to make sure you choose a standard that will support your needs.  SCSI devices are generally NOT needed by the average user.  Because there are so many standards, SCSI is slightly beyond the scope of this tutorial.  The expansion cards and drives are installed in the same way as all the other devices in this tutorial - simply follow the manufacturer’s directions for setting up the SCSI ID’s, plug in the cables, and the SCSI drives are just as easy to set up.  For more information about SCSI, go to www.adaptec.com