Installing an Optical Drive
Installation of a CD-ROM, CD-R, CD-RW, DVD-ROM, or rewriteable DVD drive can be as difficult or as easy as you make it. If you plan ahead, the installation should go smoothly.
This section walks you through the installation of a typical internal (SCSI or ATA) and external (SCSI only) optical drive, with tips that often aren't included in the manufacturers' installation manuals. After you install the hardware, your job might be finished if you are running Windows and using a Plug and Play drive, or you might have to manually load the software necessary to access the drive.
CD-ROM and DVD-ROM drives use the same ATA, SATA, and SCSI system interfaces and can be installed using the same basic procedures. Some DVD-ROM
Note that a separate analog or digital audio connection typically exists between the drive and the sound card as well, used primarily for playing audio CDs.
Avoiding Conflict: Get Your Cards in Order
Regardless of the type of installationinternal or external driveyou must have a functioning ATA or SCSI host adapter before the drive can function. In most cases, you will be connecting the optical drive to an existing ATA or SCSI adapter. If so, the adapter should already be configured not to conflict with other devices in your system. All you have to do is connect the drive with the appropriate cable and proceed from there.
Most computers today have an ATA adapter integrated into the motherboard. However, if you are adding SCSI to your system for the first time, you must install a SCSI host adapter into an expansion slot and ensure it is configured to use the appropriate hardware resources, such as the following:
As always, Windows 9x/Me/2000/XP and PnP hardware can completely automate this process; however, if you're using another operating system, you might have to configure the adapter manually.
Configuration of your new optical drive is paramount to its proper functioning. Examine your new drive and locate any
Figure 12.11. The rear connection interfaces of a typical ATA internal CD-ROM drive.
If the drive is to be the only device on your secondary ATA interface, the factory settings are usually correct. Consult the manual to make sure this is so.
When you use the CD-ROM or DVD-ROM as a secondary drivethat is, the second drive on the same ribbon cable with another devicebe sure it is jumpered as the slave drive, and configure the other device so it is the master drive (see Figure 12.12). In most cases, the drive shows up as the
Figure 12.12. An embedded ATA interface with primary and secondary ATA connections (the pen is pointing to the primary ATA connector).
Whenever possible, you should not connect a CD-ROM or DVD-ROM drive to the same channel as a hard disk drive because devices on the same channel can't
Depending on how you look at it, SCSI drives can be a bit easier to configure because you need only to select the proper SCSI ID for the drive. By convention, the boot disk (the C: drive) in a SCSI system is set as ID0, and the host adapter has an ID of 7. You are free to choose any ID in between that is not being used by another device. Most SCSI devices use some type of rotating or pushbutton selector to cycle between the SCSI IDs, but some might use jumpers.
SCSI devices are cabled together in a bus configuration. If your new SCSI drive
External (SCSI) Drive Hookup
Unpack the drive
With the exception of the SCSI host adapter, this is the bare minimum you need to get the drive up and running. You'll probably also find a CD caddy, documentation for the drive, driver software, a SCSI terminator plug, and possibly a sampling of CDs to get you started. SCSI drives almost never come with the SCSI host adapter necessary to connect them to the system. Because SCSI is designed to support up to 7 devices on the same system (or up to 15 devices for Ultra2 SCSI), including a host adapter with every peripheral is
To begin the installation, take a look at your work area and the SCSI cable that came with the drive. Where will the drive find a new home? You're limited by the length of the cable. Find a spot for the drive, and insert the power cable into the back of the unit. Be sure you have an outlet or, preferably, a free socket in a surge-suppressing power strip to plug in the new drive.
Figure 12.13. External drive with dual SCSI connectors.
A SCSI device should include some means of terminating the bus, when necessary. The terminator might take the form of a cableless plug you connect to the second SCSI connector on the drive, or the drive might be self-terminating, in which case there should be a jumper or a switch you can set to activate termination.
Finally, your external drive should have a SCSI ID select switch on the back. This switch sets the identification number the host adapter uses to distinguish the drive from the other devices on the bus. The host adapter, by most manufacturers' defaults, should be set for SCSI ID 7, and some (but not all) manufacturers reserve the IDs 0 and 1 for use by hard disk drives. Be sure you set the SCSI ID for the CD-ROM or DVD-ROM drive to any other number6, 5, or 4, for example. The only rule to follow is to be sure you do not set the drive for an ID that is already occupiedby either the adapter or any other SCSI peripheral on the bus.
Internal Drive Installation
Unpack your internal drive kit. You should have the following pieces:
Your manufacturer also might have provided a power cable splittera bundle of wires with plastic connectors on each of three ends. A disc caddy and owner's manual might also be included. If you do not already have one in the computer, you also will need a SCSI host adapter to connect SCSI peripherals.
Make sure the PC is turned off, and remove the cover from the case. Before installing a SCSI adapter into the PC's expansion bus, connect the SCSI ribbon cable to the adapter card (see Figure 12.14).
Figure 12.14. Connecting a ribbon cable to a SCSI adapter.
Ribbon Cable and Card Edge Connector
The ribbon cable should be identical on both ends. You'll find a red stripe or
Along one edge of your SCSI adapter is a double row of 50 brass-colored pins. This is the card edge connector. In small print along the base of this row of pins you should find at least two
Next, insert the adapter card into a free bus slot in the computer, leaving the drive end of the cable loose for the time being.
Choose a bay in the front of your computer's case for your internal drive. Make sure it's easily accessible from the outside and not blocked by other items on your desk. You'll be inserting the CDs or DVDs here, and you'll need the
Remove the drive bay cover from the computer case. You might have to loosen some screws to do this, or the cover might just pop off. Inside the drive bay, you should find a metal enclosure with screw holes for mounting the drive. If the drive has mounting holes along its side and fits snugly into the enclosure, you won't need mounting rails. If it's a loose fit, however, mount the rails along the sides of the drive with the rail screws, and then slide the drive into the bay. Secure the drive into the bay with four screwstwo on each side. If the rails or drive don't line up evenly with four mounting holes, be sure you use at least two screwsone mounting screw on each side. Because you'll be inserting and ejecting many discs over the
Once again, find the striped side of the ribbon cable and align it with pin 1 on the drive's edge connector. Either a diagram in your owner's manual or a designation on the connector itself
The back of the drive has a four-pin power connector outlet. Inside the case of your PC, at the back of your floppy or hard disk, are power cordsbundled red and yellow wires with plastic connectors on them. You might already have a power connector lying open in the case. Take the open connector and plug it into the back of the power socket on the CD-ROM or DVD-ROM drive. These connectors can go in only one way. If you do not have an
It's preferable to "
Do not replace the PC cover yetyou need to make sure that everything is running
SCSI Chains: Internal, External, or Both
Remember, one of the primary reasons for using the SCSI interface for your CD-ROM or DVD-ROM drive is the capability to connect a string of peripherals from one adapter, thus saving card slots inside the PC and limiting the nightmare of tracking IRQs, DMAs, and I/O memory addresses.
You can add hard drives,
Figure 12.15. A SCSI chain of devices on one adapter card.
Example One: All External SCSI Devices.
Say that you installed your CD-ROM or DVD-ROM drive and added a tape device to the SCSI bus with the extra connector on the back of the optical drive. The first device in this SCSI bus is the adapter card itself. Most modern host adapters are
, meaning they will terminate
From the card, you ran an external cable to the optical drive, and from the optical drive, you added another cable to the back of the tape unit. You must now terminate the tape unit as well. Most external units are
Example Two: Internal Chain and Termination.
On an internal SCSI bus, the same rules apply: All the internal devices must have unique SCSI ID numbers, and the first and last devices must be terminated. In the case of internal devices, however, you must check for termination. Internal devices typically have DIP switches or terminator
Most internal SCSI devices ship with terminating resistors or DIP switches onboard, usually the latter. Check your
Example Three: Internal and External SCSI Devices. If you mix and match external as well as internal devices, follow the same rules. The bottom example shown in Figure 12.16 has an internal CD-ROM drive, terminated and set for SCSI ID 6; the external hard drive also is terminated and is using SCSI ID 5. The SCSI adapter itself is set for ID 7 and, most importantly, its termination has been disabled because it is no longer at the end of the bus.
Figure 12.16. Examples of various SCSI termination scenarios.
As with any adapter card, be careful when handling the card itself. Be sure to ground yourself first.
To help you determine whether your SCSI interface card and devices are functioning properly, Adaptec
If you don't see any devices listed, you might have a termination problem. Shut down your system and your devices. Then, check terminator plugs, switches, or resistor packs. If they appear correct, turn on the external devices about 5 seconds before you start the system. A multiswitch power director with
One peculiarity of the Adaptec SCSI Interrogator is that it lists a "host adapter #1" that's actually your ATA interface! If your SCSI card isn't working, both "host adapter #0" and "host adapter #1" are actually ATA. You can tell whether this is happening with Windows 9x because it will list "ESDI_506" as the driver version.