10.4 Installing and Configuring a CD-ROM Drive
External CD-ROM drives are
"installed" simply by connecting
them to the parallel or SCSI port, as appropriate, and connecting
power, although SCSI
models may require setting jumpers to configure SCSI ID and
termination. Internal CD-ROM drives are 5.25" half-height devices,
and require the same physical installation steps as any other 5.25"
externally accessible drive. The exact configuration steps required
differ between ATAPI and SCSI interfaces, as described in the
following sections.
10.4.1 Installing and Configuring an ATAPI CD-ROM Drive
ATAPI
CD-ROM drives are installed
just like any other ATAPI/IDE device. Other than physical
installation, the only decisions you need make are whether to install
the drive on the Primary or Secondary ATA interface and whether to
jumper the drive as Sole, Master, or Slave. In general, use the
following guidelines:
On a system with one or two ATA hard drives and one ATAPI CD-ROM
drive, install the first hard drive as
Primary Master (PM), the second hard
drive, if present, as Primary Slave (PS), and the CD-ROM drive as
Secondary Master (SM).
On a system with three ATA hard drives and a CD-ROM drive, install
the first two hard drives as above, the third hard drive as SM, and
the CD-ROM drive as Secondary Slave (SS).
On a system with one or two ATA hard drives, an ATAPI CD-ROM drive,
and an ATAPI tape drive, install the hard drives as above, the CD-ROM
drive as SM, and the tape drive as SS.
On a system with an ATA hard drive, an ATAPI CD-ROM drive, and an
ATAPI CD writer, jumper the hard drive PM, the CD-ROM drive PS, and
the CD writer SM. The goal is to have the CD writer on a different
ATA channel than any drive that may be used as a source, including
the CD-ROM drive and the hard drive.
On a system with two ATA hard drives, an ATAPI CD-ROM drive, and an
ATAPI CD writer, jumper the first hard drive PM, the CD-ROM drive PS,
the second hard drive SM, and the CD writer SS. Recognize that
attempting to create a CD from data on the second hard drive risks
data corruption, because the second hard drive and the CD writer are
on the same ATA channel.
On a system with an ATA hard drive, an ATAPI CD-ROM drive, an ATAPI
CD writer, and an ATAPI tape drive, jumper the hard drive PM, the
CD-ROM drive PS, the CD writer SM, and the tape drive SS.
ATAPI CD-ROM drives require no special configuration steps to
function. All recent operating systems, including Windows 95/98 and
Windows NT/2000/XP, load ATAPI drivers and recognize ATAPI drives
automatically.
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We occasionally receive reports of ATAPI
CD-ROM drives that work properly when configured as Slave, but not
when configured as Sole or Master, even when they are the only device
on the channel. We have never encountered this situation in working
with hundreds of systems and CD-ROM drives over the years. However,
it has been reported to us often enough that we believe a problem may
exist, although we do not have adequate information to determine what
combination of controller, drive, operating system, and so on causes
the problem.
In theory, any ATAPI CD-ROM drive can function as a Master, Slave, or
Sole drive on an ATA channel. That has been our experience. Many
CD-ROM drives are designed to function properly as the only drive on
a channel even when they're jumpered Slave.
That's a matter of convenience, and to avoid support
calls when a user forgets to change the default jumpering, which is
almost always Slave. Configuring an ATAPI device as a Master-less
Slave is not officially supported in the ATA/ATAPI specification,
though.
We speculate that one possible cause of the confusion is that an ATA
channel may be set to use bus mastering (DMA). If
that's the case, making a non-DMA capable CD-ROM
drive the Master might indeed cause problems, although we have not
tried this configuration. A channel must run both devices either PIO
or DMA, and the presence of a non-DMA device on the channel should
make that channel revert to PIO, whatever the configuration settings
happen to be. Most (but not all) currently shipping ATAPI CD-ROM
drives are DMA-capable.
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10.4.2 Enabling Bus Mastering (DMA) Support
By default, ATAPI CD-ROM drives usually operate in
Programmed I/O (PIO) mode rather than
Direct Memory Access (DMA) mode, which is also called
Bus Mastering mode. The fact that PIO mode
limits DTR to 16.7 MB/s versus the 33.3 or 66.7 MB/s DTR available
with DMA is unimportant, because no current CD-ROM drive even
approaches the DTR limit
of PIO mode. What is important is that PIO mode causes much higher
CPU utilization than DMA mode. A typical ATAPI CD-ROM drive operating
in PIO mode may occupy 80% or more of the CPU when the drive is being
accessed heavily, while the same drive operating under the same
conditions in DMA mode may occupy only 1% to 5% of CPU time.
Accordingly, enabling DMA mode is usually a good idea, but doing so
requires that the BIOS, operating system, chipset, and CD-ROM drive
itself all support DMA mode. Most, but by no means all, recent ATAPI
CD-ROM drives support DMA mode. Most motherboards of late Pentium
vintage or later also support DMA mode on their embedded ATAPI
interfaces. All versions of Windows 95/98, and Windows NT 4 with
Service Pack 3 or later support DMA mode. The exact steps required to
enable DMA mode differ according to your chipset and the exact
version of Windows you are using, as follows:
- Windows 95
-
Identify the exact release of Windows 95 you are using by
right-clicking My Computer and choosing Properties. The General page
displays the minor version number, as follows:
- 4.00.950 (Windows 95 Retail) or 4.00.950a (OEM Service Release 1)
-
No DMA driver is supplied with these versions. If your computer uses
an Intel 430 or 440 chipset, download the Intel Windows 95 Bus
Mastering IDE driver from ftp://download.intel.com/design/pcisets/busmastr/bmide_95.exe
and install it following the directions supplied with the driver. The
Intel BM-IDE driver works directly with the chipset, and does not
require a system BIOS that supports DMA. Many CDs supplied with
motherboards contain the Intel BM-IDE driver. If the version you have
is 3.01 or earlier, do not install it. Download and install Version
3.02 or higher. If your computer uses a non-Intel chipset, visit the
web page for the motherboard or chipset manufacturer to locate
drivers.
- 4.00.950b (OSR 2/2.1) or 4.00.950c (OSR 2.5)
-
A native DMA driver is supplied with these versions. Use that driver
rather than the driver supplied by Intel or another chipset
manufacturer. The Microsoft drivers require DMA support in BIOS, so
you may need to flash your system BIOS to the latest version before
installing the driver. Before installing the Microsoft driver, remove
the Intel BM-IDE driver (if present) by running the BM-IDE
installation program and choosing deinstall. To install the Microsoft
driver, right-click My Computer, choose Properties, and then click
the Device Manager tab. Locate the CD-ROM drive and double-click it
to display the Properties sheet. Click the Settings tab and mark the
DMA checkbox in the Options section. Close the dialog and reboot the
system. Redisplay the Properties sheet for the drive after rebooting
to verify that the checkbox remains marked and that DMA is enabled.
- Windows 98/98SE/Me
-
The original Windows 98 release and Windows 98 SE are both identified
as 4.10.1998, and both are supplied with a native DMA driver, as is
Windows Me. To enable it, follow the same steps described above for
Windows 95 OSR 2 or higher. Note the following considerations for
Windows 98/98SE/Me and DMA:
On a clean install, we found that Windows 98/98SE/Me automatically
determines whether the chipset, drives, and BIOS support DMA. If so,
DMA is automatically enabled by default.
On an upgrade install to a system running Windows 95 OSR1 or earlier,
we found that Windows 98/98SE/Me Setup does not install DMA support,
even if all required elements are present. If this occurs, you can
enable DMA support by marking the DMA checkbox and restarting the
system.
On an upgrade install to a system running Windows 95 OSR2 or higher,
we found that Windows 98/98SE/Me Setup enables DMA only if Windows 95
had the Microsoft DMA drivers installed and enabled. If the drivers
were not installed, or if they were installed but DMA was not
enabled, Setup installs using PIO mode. Again, you can enable DMA
support manually by marking the DMA checkbox and restarting the
system.
Installing Windows 98/98SE/Me as an upgrade on a Windows 95 system
running the Intel BM-IDE driver causes all sorts of IDE problems. The
Intel BM-IDE driver version 3.01 has no uninstall option, but can be
uninstalled using the version 3.02 or higher setup program. Before
upgrading to Windows 98/98SE/Me, run BM-IDE version 3.02 or higher
and choose the deinstall option.
- Windows NT 4
-
The early versions of Windows NT 4 have no DMA support. Microsoft
began shipping a DMA driver with Service Pack 3, but we have had
various problems with that driver. The driver supplied with Service
Pack 4 or later seems to function properly. To enable DMA on a
Windows NT 4 system, take the following steps:
If you have not already done so, download and apply Service Pack 4 or
later.
Run Dmacheck.exe from the
\support\utils\i386 directory.
The dialog indicates the present status of DMA on each ATA channel.
Mark the DMA Enabled option button on the channel(s) you want to
enable DMA for. Note that if a channel has two ATA devices connected,
you should not enable DMA unless both devices are DMA-capable.
Restart the computer and run Dmacheck.exe again. The channel(s) you
enabled should still have the DMA Enabled option button marked. If
that is not the case, either the ATA interface or one or more devices
on the channel are not DMA-capable.
- Windows 2000/XP
-
Windows 2000 and Windows XP generally manage DMA properly and
automatically. During a fresh install, Windows 2000/XP tests the ATA
interface and the connected devices to determine DMA compatibility.
If the interface and all connected devices are DMA-compatible,
Windows 2000/XP enables DMA for that interface. A problem may arise
during an upgrade installation, however. If the earlier OS version
was not configured to use DMA, Windows 2000/XP may not enable DMA
even though the interface and devices support it. To check DMA status
on a Windows 2000/XP system, and to enable DMA if necessary, take the
following steps:
If you're not sure how your CD-ROM drive is
configured, restart the system and watch the BIOS boot screen to
determine whether the drive is connected to the Primary or Secondary
ATA channel and whether it is configured as Master or Slave.
Right-click the My Computer icon and choose Properties. Click the
Hardware tab and then the Device Manager button to display Device
Manager.
Locate the IDE ATA/ATAPI Controllers entry and click the + icon to
expand the listing. There should be three lines visible, assuming
that both IDE channels are enabled. The first, which will be
something like Intel® 82801BA Bus Master IDE Controller,
is for the ATA controller itself. The two remaining lines should be
Primary IDE Channel and Secondary IDE Channel.
Right-click the channel to which your CD-ROM drive is connected,
choose Properties, and then click the Advanced Settings tab to
display the IDE Channel Properties dialog. This dialog, shown in
Figure 10-2, has two sections, one for Device 0
(Master) and another for Device 1 (Slave). The listing for your
CD-ROM drive should display the DMA mode currently in use in the
Current Transfer Mode box. If it does, your drive is operating at
peak efficiency, and you can exit the dialog. For example, Figure 10-2 shows that the CD-ROM drive installed as the
master device on the secondary IDE channel is using Multi-Word DMA
Mode 2, which is the highest DMA standard it supports.
 If the Current Transfer Mode box for the CD-ROM drive lists PIO Mode,
check the setting for that device in the Transfer Mode box. If the
drop-down list in that box is set to DMA if
available, that means that Windows has determined that
either the interface or the drive (or both) does not support DMA.
Exit the dialog and resign yourself to running in PIO mode. If the
Transfer Mode box is set to PIO Only, use the drop-down list to
change that setting to DMA if available, save
your changes, restart the system, and redisplay that dialog. If the
Current Transfer Mode box for the drive now displays a DMA mode, the
drive is now using DMA. If the box still displays PIO Mode, Windows
has determined that it is unsafe to use DMA mode.
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Regardless of operating system, it's a bad idea to
configure a PIO-mode device to share an ATA channel with a
DMA-capable device. That's because ATA
doesn't allow mixing DMA mode and PIO mode on one
channel. If one device runs PIO mode, both must do so, which cripples
the DMA-capable device. In particular, it's a
horrible idea to put a PIO-only CD-ROM drive on the same channel as
an Ultra-DMA hard drive, because that means the hard drive will run
in PIO mode, which cuts throughput by half or more and dramatically
increases CPU utilization. Put the PIO-only drive on its own channel,
alone or with another PIO-only device, or replace the drive with a
DMA-capable drive.
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10.4.3 Installing and Configuring a SCSI CD-ROM Drive
Installing and
configuring a SCSI drive is somewhat more involved. Rather than
attempting to provide step-by-step instructions, which vary according
to the specific drive and adapter, we've chosen to
illustrate a typical installation using a Plextor UltraPlex 40Xmax
drive and an Adaptec 2930 SCSI host adapter, noting potential
pitfalls along the way:
If you have not already done so, the first step is to install the
SCSI host adapter. To do so, power down the system, remove the cover,
and locate an unused PCI expansion slot that supports bus mastering.
Many recent systems support bus mastering on all available slots.
Older systems may support bus mastering on only some slots. In that
case, the slots capable of bus mastering are normally white or ivory,
and those not capable of bus mastering are brown or black. Remove the
slot cover for the selected slot, align the bus connector with the
slot, and press down firmly to seat the adapter. Use the screw that
secured the slot cover to secure the adapter. If you have a spare
drive activity indicator LED, you can connect it to J2 on the host
adapter (pins 1 and 2 if the cable has only two positions).
Both the Plextor drive and the Adaptec host adapter fully support
SCAM (SCSI Configured Auto-Magically), a kind of Plug-N-Play for
SCSI. Note the following issues when working with SCAM:
SCAM-compliant
drives like the Plextor UltraPlex 40Xmax
allow a SCAM-compliant host adapter like the Adaptec 2930 to set the
drive's SCSI ID and termination status
automatically.
SCAM-tolerant drives report their SCSI ID and
termination status to the adapter, but cannot reset SCSI ID or
termination status automatically. Instead, you must change jumpers or
switches on the drive manually to set SCSI ID and termination.
Non-SCAM drives do not even report their current
settings to the adapter, let alone allow the adapter to reset them
automatically. When using non-SCAM devices, you must manually verify
settings and change them as necessary. Note that enabling SCAM on the
host adapter may cause your computer to hang if you connect a
non-SCAM drive, because the adapter is unable to determine current
settings for the non-SCAM device. If this occurs, use the Adaptec
SCSISelect utility at boot time to disable SCAM on the adapter.
If you are installing a non-SCAM adapter and/or drive, you must set
SCSI IDs manually using the jumpers or switches on the adapter and
drive. If the adapter supports seven devices (plus the adapter
itself), the adapter is normally configured as SCSI ID 7 (the highest
priority SCSI ID), leaving SCSI IDs 0 through 6 available for drives.
ID 0 is normally reserved for the boot hard disk, and ID 1 for a
secondary hard disk. A CD-ROM drive should normally be assigned to ID
2 or higher. If the host adapter is dedicated to devices other than
hard drives, it is acceptable to assign ID 0 or ID 1 to the CD-ROM
drive.
If you are installing a non-SCAM adapter and/or drive, you may also
need to terminate the SCSI bus manually. Exactly two devices must be
terminated on each SCSI bus, and these devices must be those at each
end of the bus, as follows:
If the SCSI adapter has only internal devices attached to it, the
adapter itself and the final device on the internal SCSI chain must
be terminated.
If the SCSI adapter has only external devices attached to it, the
adapter itself and the final device on the external SCSI chain must
be terminated.
If the SCSI adapter has both internal and external devices attached
to it, do not terminate the SCSI adapter itself.
Instead, terminate the final device attached to the internal chain
and the final device attached to the external chain.
Note that most recent SCSI host adapters, including the Adaptec 2930,
can automatically detect the presence of terminated SCSI devices on
the bus and automatically set their own termination status
accordingly. On Adaptec models, which we recommend exclusively, this
option can be enabled or disabled by using SCSISelect to set Host
Adapter Termination to AutoTerm, which is the default setting. Also
note that a few internal SCSI cables have a built-in terminator at
the end of the cable. If you use such a cable, make sure that
termination is disabled on all drives connected to that cable.
Once you have resolved SCSI ID and termination issues and have the
drive physically installed, the next step is to connect the cables.
Most adapters are supplied with a standard two-device cable. If you
need to connect more than two drives, replace the cable before
proceeding. Otherwise, connect the cable to each drive, making sure
to align pin 1 on the cable (indicated by a red stripe) with pin 1 on
each device (indicated by a small number, triangle, or dot on the
connector). It doesn't matter which drive connects
to which cable position, so mix and match drives and cable positions
in whatever way makes it easiest to route the cable. Also connect the
power cable and the audio cable that links the CD-ROM drive to the
appropriate connector on your sound card or motherboard.
After verifying all settings and connections, turn on any external
SCSI device(s) first, and then turn on the PC. Ordinarily, the system
should boot normally, but the SCSI CD-ROM drive may or may not be
recognized, depending on your operating system and other factors.
Before you configure the operating system to use the drive, however,
some systems may require that you complete one or both of the
following steps:
- CMOS Setup
-
On most systems, the PCI bus assigns IRQs and port addresses
automatically. If your system requires setting PCI bus parameters
manually, do so during the first restart, using the system or
motherboard documentation for guidance.
- SCSI Setup
-
The SCSI BIOS displays its own splash screen while initializing,
which normally displays adapter and BIOS information and a list of
installed SCSI devices. Ordinarily, the default settings are fine,
but in some cases you may need to change settings to get the drive to
work at all or to optimize its performance. If this is the case for
your system, press whatever key sequence is needed to invoke the SCSI
Setup routine and make the necessary changes, as recommended by the
documentation for the host adapter and/or drive.
If either or both of these steps are needed, restart the system after
completing each.
10.4.4 General SCSI CD-ROM Troubleshooting
If you have installed your SCSI host
adapter and drive properly and installed the requisite drivers
(described in the following sections) and your drive does not work,
check the following items before proceeding to other troubleshooting
steps:
Is the host adapter installed in a bus-mastering PCI slot? Verify
with the system or motherboard documentation that the chosen slot
supports bus mastering, or try another slot.
Are all SCSI devices turned on, and were they turned on when you
booted the system? The SCSI adapter recognizes only devices that are
active when the system boots. If necessary, power down all SCSI
devices, turn off the computer, turn the SCSI devices back on, and
then turn the PC back on.
Are all SCSI cables and power cables connected properly? Verify that
the pin 1 orientation of all SCSI cables and devices is correct, and
that the power cable is fully seated in each SCSI drive.
Does each SCSI device on the bus, including the host adapter, have a
unique SCSI ID, and is the bus terminated correctly? If not, correct
the ID assignments and/or termination and restart the system.
If SCAM is enabled on your host adapter, are you certain that all
connected devices are SCAM-compliant (or at least SCAM-tolerant)? If
not, either replace the non-SCAM device, or disable SCAM on the
adapter and configure SCSI IDs and termination manually.
Are you certain that you have installed all driver software that your
adapter and/or devices require?
10.4.5 Windows 9X/2000/XP SCSI Driver Installation and Troubleshooting
Ordinarily, Windows 9X/2000/XP
automatically detects installed SCSI host adapters and devices. If it
does not, first verify that the hardware is installed and configured
properly. If there is no apparent hardware problem, use the Add New
Hardware Wizard to force installation of the necessary drivers for
the new hardware.
To do so, open Control Panel (Start  Settings
Control Panel) and double-click Add New Hardware.
Accept the default selection to allow Windows to attempt to
auto-detect the new hardware. If Windows fails to detect the
hardware, or locks up during the detection process, restart the
system, reinvoke the Add New Hardware Wizard, and this time tell it
that you want to select from a list. If you have a driver disk
supplied by the manufacturer, choose the Have Disk option at the
appropriate point in the process. Otherwise, use the lists of
manufacturers and models displayed by the Add New Hardware Wizard to
select the standard Windows drivers for the installed devices. If no
listed device exactly matches what is installed, you can sometimes
use the most closely similar device that is listed. Ordinarily, the
driver will load correctly and the device will be recognized. If
problems occur, take the following steps to resolve them:
Open Device Manager (Start Settings
Control Panel System
Device Manager). Locate the SCSI controller item
in the list, and click the plus sign to its left to expand the
listing. Your SCSI host adapter should be listed. If it is not and
you have not yet installed drivers manually, exit Device Manager and
install the drivers. If you have already attempted a manual
installation and are certain that all hardware is properly installed
and configured, contact the manufacturer or dealer for a replacement
device.
If the device is listed, highlight it and click Properties to display
the General page of the property sheet for the device. The Device
Status section should state "This device is working
properly." If it does not, the most likely causes
are a resource conflict or a hardware problem. The Device usage
section contains a list of stored hardware profiles. Make sure that
the checkbox for current configuration (and any other configurations
for which you want to use this device) is marked.
Click the Resources tab and examine the Conflicting Device list
section at the bottom, which should state, "No
conflicts." If a conflicting device is listed,
reconfigure one or both devices to eliminate the conflict.
After making any necessary changes to the General page and the
Resources page, save your changes and restart the system. The device
should be recognized properly. If it is not, contact the adapter
manufacturer's technical support.
10.4.6 Windows NT 4 SCSI Driver Installation and Troubleshooting
After ensuring that the SCSI adapter and devices are installed and
configured properly, restart Windows NT. Open Control Panel
(Start Settings Control Panel)
and double-click SCSI Adapters. Windows NT displays the SCSI Adapters
dialog Devices page, which shows installed SCSI (and IDE) adapters.
Click Add to install the device drivers for the host adapter. Windows
NT displays a Creating Driver List progress bar as it builds the
driver list, and then displays the Install Driver dialog, which
contains a list of manufacturers in the left pane and a list of SCSI
adapters for the selected manufacturer in the right pane. Select the
manufacturer and adapter from these lists only if you do not have a
more recent driver supplied by the manufacturer. If you have a driver
disk, click Have Disk and follow the prompts. In either case, if
drivers already exist on the system, you'll be asked
whether you want to use the existing drivers or install new drivers.
When so prompted, install the new drivers unless you have good reason
to keep the old ones. After driver installation completes, restart
the system to load the drivers. Ordinarily, the driver will load
correctly and the device will be recognized. If problems occur, use
the following methods to resolve them:
10.4.7 Changing CD-ROM Drive Letter Assignments
By default, all versions of Windows assign a CD-ROM drive the next
available drive letter following those for any local volumes. If you
subsequently install an additional hard disk or repartition your
drive to create additional volumes, the letter assigned to the CD-ROM
drive may change, which may confuse installed software that attempts
to access the CD-ROM drive as the old letter. You can avoid this
"musical chairs" reassignment of
CD-ROM drive letters by manually assigning the CD-ROM drive a drive
letter that is higher than the drive letter for any existing local or
network volume. We use R: for the CD-ROM drive
by long-standing habit, although there is something to be said for
assigning it to Z:. To assign a different drive
letter to the CD-ROM drive, proceed as follows:
- Windows 95/98/98SE/Me
-
Right-click the My Computer icon, choose Properties, and then click
the Device Manager tab. Double-click the CD-ROM drive to display its
Properties sheet, and then click the Settings tab. Use the spinner to
assign an unused drive letter to the CD-ROM drive and then restart
the system.
- Windows 2000/XP
-
If you have not already done so, right-click the Task Bar, choose
Properties, click the Advanced tab, and mark the Display
Administrative Tools checkbox in the Start Menu Settings pane. From
Control Panel, choose Administrative Tools
Computer Management. In Computer Management, expand the tree if
necessary to show items in the Storage branch. Click Disk Management,
locate your CD-ROM drive in the lower-right pane, right-click its
icon to display the context-sensitive menu, and choose the menu item
Change Drive Letter and Path. Assign an available drive letter to the
CD-ROM drive, save your changes, and exit. Once you accept the
changes, the new drive letter takes effect immediately.
- Windows NT 4
-
Start Disk Administrator (Start Programs
Administrative Tools (Common)
Disk Administrator). Right-click the CD-ROM drive and mark the Assign
Drive Letter option box. Use the drop-down list to assign the desired
drive letter and click OK. Windows NT displays a confirmation dialog.
If you accept the change, the new drive letter becomes active
immediately.
If you change the drive letter assignment for a CD-ROM drive, do so
immediately after installing the drive or the operating system. If
you use that drive under its original letter to install software,
that software will later attempt to access the drive using the old
drive letter.
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