PD System --- Read Me File
==========================

Before attempting to use this software to control your PD
System, make sure that you have set up the drive according to
the User Guide.

This document describes, in general terms, how "CorelSCSI for
PD" manages the PD System, and provides information for the
advanced use of this software.

Except for the differences described here, you can expect the
PD System to function in the same manner as two independent
devices: a CD-ROM drive and a rewritable optical drive. You
should review the PD System User Guide, Dos or Windows
Installation and this read me file for more details on the
operation of the software. Note that the rewritable optical
drive is identified in the applications and the remainder of
this document as an optical device.

The optical device driver, UNI_ASP.SYS, and the CD-ROM device
driver, CUNI_ASP.SYS, automatically detect the PD System on
startup. You don't have to make any configuration changes to
the CorelSCSI drivers to properly support this drive.

The drivers must assign two drive letters to the PD System.
The rewritable device driver assigns one drive letter. 
The CD-ROM device driver and the CD-ROM extensions program, 
CorelCDX or MSCDEX, assign a second drive letter.


Chapter 1 - DOS/Windows Reference
---------------------------------

1.1	Allocating Drive Letters
--------------------------------

During the installation, you will be promted to allocate
enough drive letters for the SCSI devices you're using.
Please note that the PD System requires two drive letters
to be allocated. This modifies the LASTDRIVE command in
your CONFIG.SYS file. For more information about the
LASTDRIVE command, see your DOS documentation.

1.2	Using Two or More Host Adapters
---------------------------------------

If your system includes more than one type of host adapter,
you must load the ASPI driver for each host adapter. This
software provides ASPI drivers for many host adapters. To
install more than one ASPI, run the installation once for
each ASPI you require.

This software assigns adapter numbers based on the order
that the ASPI drivers are listed in your CONFIG.SYS file:
adapter number 0 is assigned to the first ASPI driver;
adapter number 1 is assigned to the second ASPI driver,
and so on.

If you've installed two or more of the same type of host
adapter, a single ASPI driver manages both adapters. Some
ASPI drivers automatically manage multiple cards; other
ASPI drivers require that you explicitly specify
multi-card options.

If this software doesn't include the ASPI driver you
require, see the documentation provided with your SCSI
interface for information about installing its ASPI driver.

1.3	Using Memory Managers
-----------------------------

If you're using a memory manager, you must exclude the
address of your host adapter in the CONFIG.SYS file.
Excluding this address prevents address conflicts between
the memory manager and the host adapter.
For example:

If you're using the QEMM memory manager and a host adapter
that covers the address range from d800 to dbff, you would
specify the following in your CONFIG.SYS file:

DEVICE=C:\QEMM\QEMM386.SYS  x=d800-dbff

If you're using the EMM386 memory manager and a host
adapter that covers the address range from d800 to dbff,
you would specify the following in your CONFIG.SYS file:

DEVICE=C:\DOS\EMM386.EXE  x=d800-dbff

If you're using the 386MAX memory manager and a host
adapter that covers the address range from d800 to dbff,
you would specify the following in your CONFIG.SYS file:

DEVICE=C:\386MAX\386MAX.SYS  RAM=d800-dbff

1.4	Preventing Memory Conflicts in Windows
----------------------------------------------

If you install this software for Windows, you must add the
following line to the [386Enh] section of the SYSTEM.INI
file to prevent Windows from using the memory space used by
the host adapter:

EMMEXCLUDE=(adapter address)

For example:

If you're using a host adapter that uses 16K of RAM starting
at address d800, you would enter the following:

EMMEXCLUDE=d800-dbff

For more information about the EMMEXCLUDE statement, see
your Windows SYSTEMINI.TXT README file.

1.5	Using 16-Bit VGA Cards
------------------------------

Some 16-bit VGA cards and 8-bit memory mapped cards may
cause upper memory block conflicts. If these conflicts
occur, you'll receive a No Host Adapter Found error
message. This problem isn't caused by this software.

To eliminate the conflict:

Set the memory address on your card to E000 if your system
lets cards use memory above E000. Or use your card in
8-bit mode. For information about using your card in
8-bit mode, see the documentation for your card.

1.6	Changes Made by the Installation
----------------------------------------

This installation makes changes to your system, which
include modifying the CONFIG.SYS and AUTOEXEC.BAT files.
You can choose not to update these files; however, without
the modifications, you can't use this software. Backups of
the original files are saved in the root directory as
CONFIG.00n and AUTOEXEC.00n, where the value of n starts
at 0.

The installation creates a directory in which the this
software is installed and adds the name of the directory
to the SET PATH command in your AUTOEXEC.BAT file. By
default, this directory is named CORELDRV.

The installation also creates a file named CRLSCSI.INI in
CORELDRV that defines the configuration of drivers and
utilities. For more information about CRLSCSI.INI, see
section on Configuring Drivers and Utilities.

If you install under Windows, a [CorelSCSI] section is added
to your WIN.INI file. This section includes the following
statement, by default, to indicate the location of the most
recent version of this software:

installed=C:\CORELDRV

Other changes to your system depend on the drivers and
utilities you choose to install. Since the PD System can
access both rewritable PD cartridges as well as CD and
CD-ROM disks, this installation adds device drivers for both
a rewritable optical disk drive and a CD-ROM drive. These
drivers automatically detect the PD System on startup. You
don't have to make any configuration changes to the
CorelSCSI drivers to properly support the PD System.

The drivers must assign two drive letters to the PD System.
The rewritable device driver assigns one drive letter. The
CD-ROM device driver and the CD-ROM extensions program,
CorelCDX or MSCDEX, assign a second drive letter.

For rewritable devices, the installation modifies CONFIG.SYS
to indicate the location of the Corel rewritable device
driver, named UNI_ASP.SYS.

By default, the command looks like this:
DEVICE=C:\CORELDRV\UNI_ASP.SYS

For a CD-ROM drive, the installation modifies CONFIG.SYS to
indicate the location of the CD-ROM device driver, named
CUNI_ASP.SYS.

By default, the command looks like this:
DEVICE=C:\CORELDRV\CUNI_ASP.SYS

If your system requires a CD-ROM extensions program,
AUTOEXEC.BAT is also modified to indicate the location of
CorelCDX.

By default, the command looks like this:
C:\CORELDRV\CORELCDX

1.7	A Note to MSCDEX Users
------------------------------

If the installation finds MSCDEX on your system, you're
prompted to replace MSCDEX with CorelCDX. CorelCDX provides
features that are functionally equivalent to most of the
MSCDEX options as well as providing many additional
advantages. For example, you can configure and maintain
CorelCDX using CorelSCSI utilities.

If the installation finds MSCDEX on your system and the
program uses the /K option, no changes are made to your
system. The MSCDEX /K option provides use of the shift-Kanji
character set, if it's available on your disk. This feature
isn't available with CorelCDX.

If you're using MSCDEX and it isn't using the /K option,
you're prompted to replace MSCDEX with CorelCDX.

If you choose not to replace MSCDEX with CorelCDX, the
installation adds an option to the MSCDEX command in your
AUTOEXEC.BAT file that identifies the number of the CD-ROM
device driver that MSCDEX should use. CD-ROM device drivers
are numbered from 001. Therefore, if you have two CD-ROM
device drivers, the following options are added to the
MSCDEX command by default:

/MSCD001 /MSCD002

If you install under Windows, depending on the versions of
MSCDEX and Windows you're using, you may need to add or
remove the following line from the [386Enh] section of your
SYSTEM.INI file:

DEVICE=LANMAN10.386

For more information, see your Windows README.TXT file.

1.8	A Note to Windows for Workgroups Users
----------------------------------------------

If you mapped drives under Windows for Workgroups before
installing this software for a new drive, you may need to
re-map the drive to different drive letters.

When this driver installs, it uses the first available drive
letter under DOS. Since a Windows for Workgroups drive isn't
mapped until after all DOS drivers have loaded, the driver
can't recognize the Windows mapped drive and avoids that
drive letter. The solution is to remove the drive mapping
under Windows for Workgroups and re-map the shared drive to
another letter.

If you've installed a new CD-ROM drive, correct the problem
by using the DOSCONFG or Windows SCSIConfig utilities to
modify the default CD-ROM Drive setting to a letter that is
greater than your last Windows for Workgroups drive letter.

You must also make sure that the LASTDRIVE= statement in
your CONFIG.SYS file is greater than or equal to the
selection you make for the default CD-ROM Drive.

1.9	Configuring the drive
-----------------------------

When you configured the PD System, you selected a SCSI ID 
number. 

When you use this drive with DOS, you set a dip switch for LUN
mode to Off. (The Default setting of LUN mode is Off.)

LUN mode OFF (2LUN mode)

If you configure the PD System to LUN mode Off, the PD System
automatically assigns two LUNs. One is for rewritable and
other is for CD-ROM. The drivers assign one drive letter to
each LUN. The first letter is assigned to the rewritable
optical device, LUN 0, and the second letter is assigned to
the CD-ROM device, LUN 1.

If you scan the SCSI bus using Corel's SS utility or using the 
Tools, the drive reports an optical device type for LUN 0 and 
a CD-ROM device type for LUN 1. For more information, see the 
documentation provided with your drive.

LUN mode ON (1LUN mode)

This LUN mode is for Macintosh. If you connect the PD System
to Macintosh, set LUN mode to ON.

1.10	DOSTOOLS and SCSITools
------------------------------

Using DOSTOOLS and SCSITools with the PD System is only 
slightly different from other rewritable optical and CD-ROM 
drives. If you select the PD System, the Maintenance menu 
includes four new options: PC mode, Mac mode, Enable write 
cache, and Disable write cache. The drive stores this mode and 
cache information even when the drive is disconnected from the 
computer or from the power.

If you configure the PD System to have two LUNs, 
DOSTOOLS and SCSITools identify the drive as two 
independent devices. You can select either the optical or the 
CD-ROM device, regardless of which media is in the drive. 
However, many of the Tools' functions won't work if the 
appropriate media isn't in the drive. For example, the CD-ROM 
tests won't complete successfully if a rewritable optical 
cartridge is in the drive.


1.11	Maintenance menu commands
---------------------------------

Disable write cache:
This command allows you to disable the drive's internal memory 
cache. In most cases, the cache improves the performance of 
the drive so you should leave the cache enabled. In rare 
cases, the cache could cause problems with the operation of 
some software. In this case, disable the write cache.

Enable write cache:
This command allows you to enable the drive's internal memory 
cache if it has been disabled by the Disable write cache 
command.

Mac mode:
This command allows you to configure the drive for use on a 
Macintosh computer. If you intend to use this drive with some 
older Macintosh computers, you may require this setting 
change. The Macintosh may be unable to boot from the drive if 
this change isn't made.

Selecting Mac mode disables SCSI unit attention whenever a bus 
reset, bus reset message, or power on reset is detected on the 
SCSI bus.

PC mode:
This command returns the drive to its original state before 
the Mac mode command was issued. This is the normal operating 
mode for the drive when it's used with an IBM compatible PC.
This file provides more detailed information about CorelSCSI!
for PD (DOS/Windows version) than is provided in the PD
installation guide. This information is provided as an aid to
troubleshooting and for advanced operation of the PD System.

1.12	Troubleshooting
-----------------------

If error messages about your drivers or ASPI are displayed
during the system boot, they haven't been successfully
installed. Check that you've correctly configured the jumper
settings on the host adapter. For more information about
these settings, see the installation instructions provided
with your host adapter.

If two drive letters are not displayed for the PD System,
check the drive's LUN mode setting. In order to use the PD
System on DOS/Windows, LUN mode setting shall be OFF.

You should also check the order that commands are defined in
your CONFIG.SYS file. For example, some ASPI drivers must be
loaded before memory managers are loaded.

If you don't have enough conventional memory for other
applications after installing this software:

*	reduce the number of DOS buffers in your CONFIG.SYS
	file to allow more RAM for your applications. If this
	reduces the performance of your system, use a disk
	caching program that uses expanded or extended memory.

*	reinstall this software and load the drivers in the
	upper memory blocks (UMB). For information about UMB
	setup, see your DOS documentation.

*	run the OPTIMIZE program if you're using the QEMM
	memory manager

*	run the MAXIMIZE program if you're using the 386MAX
	memory manager

*	run the MEMMAKER program if you're using DOS 6.0



Chapter 2 - Advanced Operation Reference
----------------------------------------

This chapter provides information for advanced operation of
the utilities.


2.1	Configuring Drivers and Utilities
-----------------------------------------

Configuration defines the default configuration of drivers
and utilities from within one window. Configuration settings
are maintained in the CRLSCSI.INI file, which is located in
the CORELDRV directory by default.

Using Configuration, you can configure the following drivers
and utilities, if they're installed:
*	Tools
*	CD-Audio
*	CD-ROM device driver
*	rewritable device driver
*	CorelCDX driver

You can also configure Tools from within the Tools program by
selecting Preferences from the File Menu.

To open Configuration

A)	Double-click the SCSIConfig icon for Windows, or
B)	Enter the following at the command prompt: DOSCONFG

To select a driver or utility:

Choose its name from the Window menu or choose its button
from the Tool bar for Windows.
Or choose its button from the main window for DOS.

To exit Configuration

Choose Exit from the File menu for both Windows and DOS.

2.1.1	About CRLSCSI.INI
-------------------------

When you open a CorelSCSI utility, the CRLSCSI.INI file is
checked for changes to default application settings.
Therefore, the commands included in the CRLSCSI.INI file
depend on the drivers and utilities you install and the
changes you make to default settings.

CRLSCSI.INI is intended to provide Corel Technical Support
with information about your application configuration. Don't
edit the contents of the CRLSCSI.INI file. Instead, use
either Configuration or the utility preferences to change
default settings for a utility. The CRLSCSI.INI file is
automatically updated with these changes.

If you delete CRLSCSI.INI, the file is recreated the next
time you open Configuration. However, all your utilities and
drivers are reset to their default configuration.

The following list defines all the sections and commands
that may appear in your CRLSCSI.INI file:

[apps] commands are added to the CRLSCSI.INI file when you
change the default Configuration preferences:

*	APPS indicates the available buttons and features.
*	COLOR sets the color of the Configuration window
	background.
*	SELBAR identifies the saved selection bar information.
*	TBAR identifies the saved tool bar information.

[CD-Audio 2.0] commands are added to the CRLSCSI.INI file when
you change the CD-Audio version 2.0 preferences:

*	BACKGROUND, DIM, and BRIGHT indicate colors used in the
	window.
*	FIRSTDRIVE identifies the CD-ROM drive letter used.
*	FONTFACE indicates the font used in the window.
*	NAME indicates whether the track name is displayed for
	tracks in the Track list box.
*	RDONLY displays whether the database file is read-only.
*	TIME indicates whether the window displays disc time or
	track time.
*	TIMER shows the interval, in milliseconds, at which the
	status of the CD-ROM drive is checked.
*	TYPE indicates whether the track type is displayed for
	tracks in the Track list box.
*	USELED indicates that a default font is used for the
	LED panel text.

[CDROM Device Locations] commands are added to the
CRLSCSI.INI file when you change the default settings of the
CD-ROM device driver:

*	LOCSnum verifies CD-ROM device values.

[CDROM Drivers] commands are added to the CRLSCSI.INI file
when you change the default settings of the CD-ROM device
driver:

*	AUTOSCAN indicates whether the device driver
	automatically scans for devices when loading.
*	DEVICE displays the SCSI ID, LUN, host adapter and
	device type for an included device.
*	DISABLEMULTI indicates whether you can use multi-
	session CDs.
*	DISABLEXA indicates whether you can use Photo CDs.
*	DRIVERNAME indicates the name assigned to the CD-ROM
	device driver. Corel's DOS CD-ROM device drivers are
	numbered starting from MSCD001.
*	EXCLUDE displays the SCSI ID, LUN, and host adapter of
	an excluded device.
*	NUMDEVICES displays the number of devices that the
	device driver includes.
*	NUMEXCLUDE displays the number of devices that the
	device driver is excluding.
*	PAUSE indicates whether the device driver pauses after
	loading.
*	SETVOLUME indicates whether you've set the volume level
	for audio output.
*	TIMEOUT displays the time-out value, by default 15
	seconds, for SCSI commands. For example, if an attempt
	to access a CD-ROM drive exceeds 15 seconds, an error
	message is displayed.
*	USEEMS indicates whether the device driver is loaded in
	EMS.
*	VERBOSE defines whether the screen displays information
	as the device driver is loading.
*	VOLUME displays the volume level for audio CDs.

[Corel Media Format] commands are added to the CRLSCSI.INI
file when you change the Tools format settings for media
formatted using the Corel Media format:

*	FATSIZE indicates whether a 64K FAT or a 128K file
	allocation table is created on a rewritable cartridge.
*	LOWLEVEL defines whether a low-level format must be
	performed when formatting media.
*	NFATS indicates the number of file allocation tables
	created on a rewritable cartridge.
*	ZEROCARTRIDGE specifies whether zeros are written to
	sectors of a rewritable cartridge when it's formatted.

[CORELCDX] commands are added to the CRLSCSI.INI file when
you change the default settings of CorelCDX. For more
information about CorelCDX caching, see "Understanding
CD-ROM Caching":

*	CACHE displays the number of cache buffers allocated,
	in blocks, to the path table, directory, and data
	caches, respectively. By default, CACHE=2,2,2.
	Path table, directory, and data caches can be set from
	2 to 64 blocks. Each path table and directory cache
	block requires 2K. The size of each data cache block is
	determined by the DATABLK command. Minimum, maximum,
	and alignment requirements may require that the actual
	number of buffers differ slightly from those specified.
	Typically, the MEMBUFFERS command, which distributes
	buffers among the three caches, is used rather than the
	CACHE command. However, the CACHE command allows more
	precise control over the use of allocated cache
	buffers. If both the CACHE and MEMBUFFERS commands are
	used, the CACHE values override the MEMBUFFERS value.
*	DATABLK defines the number of 2K sectors assigned to
	each data cache block. By default, DATABLK=2 sectors.
	Valid values include: 1, 2, 4, and 8. The internal
	read-ahead caching logic of some CD-ROM drives may be
	adversely affected by changing the default data cache
	block size. This option is useful for applications that
	read data from CDs in contiguous segments.
	Unless you're using CDXCACHE, setting DATABLK=1
	disables read-ahead caching. However, an additional 4K
	of conventional memory is required.
*	DRIVERNAME displays the required name of the CD-ROM
	device driver. If you enter more than one CD-ROM device
	driver name, separate each name with a comma and remove
	any blanks between names. Corel's DOS CD-ROM device
	drivers are numbered starting from MSCD001.
	Corel's NetWare CD-ROM device drivers are numbered
	starting from MSCD099.
	If CorelCDX can't find driver names in the CRLSCSI.INI
	file or if the CRLSCSI.INI file is missing, CorelCDX
	will try to locate and initialize the CD-ROM device
	drivers named, by default, MSCD001 and MSCD099.
*	EMSMODE indicates whether code, data, or cache buffers
	are to be loaded into expanded memory. This option
	doesn't affect cache buffers used by CDXCACHE.
	EMSMODE=1 loads code and data into expanded memory.
	Only a small footprint remains resident in conventional
	memory. This option may be incompatible with some
	CD-ROM applications; for example, those that perform
	absolute disk reads into expanded memory buffers.
	EMSMODE=2 loads only cache buffers into expanded
	memory. EMSMODE=3 loads code, data, and cache buffers
	into expanded memory. If you're using an expanded
	memory manager such as EMM386.EXE, then EMSMODE=3 by
	default; otherwise, EMSMODE=0 and cache buffers remain
	in conventional memory.
	In rare cases, EMSMODE=3 may cause problems when you
	try to read data from a CD-ROM drive. Some
	applications, when loaded in expanded memory, may
	create memory conflicts. If you experience problems,
	change the value of EMSMODE to 2. If cache buffers are
	loaded in expanded memory, a small amount of
	conventional memory may be allocated to store required
	tables, and so on. To make the most efficient use of
	allocated memory, the driver may slightly increase the
	number of specified cache buffers.
*	FILES sets the maximum number of CD-ROM files that can
	be open at the same time. Each file requires
	approximately 16 bytes. By default, this isn't
	available, the next available drive letter is used.
	This option is useful for software that requires
	specific drive letters for CD-ROM drives.
*	MEMBUFFERS displays the approximate number of cache
	buffers allocated, in blocks, for all CD-ROM drives.
	These cache buffers are distributed among the path
	table, directory, and data caches. By default,
	MEMBUFFERS=8. Typically, the MEMBUFFERS command is used
	rather than the CACHE command. However, the CACHE
	command allows more precise control over the use of
	allocated cache buffers. If both the CACHE and
	MEMBUFFERS commands are used, the CACHE values override
	the MEMBUFFERS value.
*	SHARE indicates whether to permit CD-ROM drive sharing
	with Windows for Workgroups. By default, SHARE=NO.
*	VERBOSE specifies whether information about CorelCDX is
	displayed on the screen as CorelCDX is loading. By
	default, VERBOSE=NO.
*	XMSBLOCK indicates the maximum size, in sectors, of
	read request that will be cached by CDXCACHE. The cache
	performance may benefit from larger values. However,
	the cache may fill up more quickly. By default,
	XMSBLOCK=4.
*	XMSPAGE indicates the number of sectors per cache page,
	which determines the read-ahead operations. This option
	affects only CDXCACHE. The value of 4 is recommended
	for smaller cache sizes; it's more important to cache
	separate disk reads than to perform read aheads. Use
	the value 8 for larger cache sizes; more data is stored
	in one operation. The default setting is 4 sectors per
	cache page.
*	XMSSIZE indicates the size, in kilobytes, of the
	CDXCACHE. Set the size to 0 to disable this cache.
	A size of -1 creates a default cache size equal to one-
	quarter of the free extended memory. You can also set
	the size to a value from 64 to 16384.

[CorelSCSI Tools] commands are added to the CRLSCSI.INI file
when you change the application settings for Tools:

*	LOG displays a name for the log file.
*	LOGDIR indicates a name for the log directory.
*	MODE provides the Tools mode: normal or advanced.

[Device Names] commands are added to the CRLSCSI.INI file
when you define names for devices using the Backup options:

*	DEVICE displays the device name.
*	NAME provides information about the named device.
*	NAMEDDEVICES shows the number of named devices.

[DOS Media Format] commands are added to the CRLSCSI.INI
file when you change the Tools format settings for media
formatted using the DOS Media format:

*	FATSIZE indicates whether a 64K FAT or a 128K file
	allocation table is created on a rewritable cartridge.
*	LOWLEVEL defines whether a low-level format must be
	performed when formatting media.
*	NFATS indicates the number of file allocation tables
	created on a rewritable cartridge.
*	ZEROCARTRIDGE specifies whether zeros are written to
	sectors of a rewritable cartridge when it's formatted.

[Hard Disk Media Format] commands are added to the
CRLSCSI.INI file when you change the Tools format settings
for media formatted using the Hard Disk Media format:

*	FATSIZE indicates whether a 64K FAT or a 128K file
	allocation table is created on a rewritable cartridge.
*	LOWLEVEL defines whether a low-level format must be
	performed when formatting media.
*	NFATS indicates the number of file allocation tables
	created on a rewritable cartridge.
*	ZEROCARTRIDGE specifies whether zeros are written to
	sectors of a rewritable cartridge when it's
	formatted.

[SCSI Diags] commands are added to the CRLSCSI.INI file when
you change the settings for Tools diagnostic tests:

*	LOOPS displays the number of times tests are run.
*	TESTS indicates which tests are run.

[SCSI Utils] commands are added to the CRLSCSI.INI file when
you change the utilities settings for Tools:

*	ERASE shows the type of tape erase method.
*	SCAN indicates whether a scan searches for SCSI IDs
	only or SCSI IDs and LUNs.

[UNI Device Locations] commands are added to the CRLSCSI.INI
file when you change the default settings of the rewritable
device driver:

*	LOCSnum verifies device information.

[UNI Drivers Advanced] commands are added to the CRLSCSI.INI
file when you change the default settings of the rewritable
device driver:

*	BOOTWRITE indicates whether boot sector overwrites are
	enabled.
*	DEVICESIZE displays the largest amount of storage on
	the cartridge.
*	FLUSHCOUNTER shows the number of continuous writes
	before the device driver automatically flushes its
	buffers to the cartridge.
*	FLUSHTIMER indicates how often cache buffers are
	flushed.
*	MOUNT displays the number of bad sectors allowed during
	a mount.
*	SCACHE indicates the number of system cache buffers.
*	SECTORSIZE indicates the largest sector size you plan
	to use on a cartridge.
*	TIMEOUT displays the number of seconds of inactivity
	the device driver waits for before flushing its
	buffers.
*	VERIFY indicates whether information written to the
	cartridge is verified.

[UNI Drivers] commands are added to the CRLSCSI.INI file
when you change the default settings of the rewritable
device driver:

*	AUTOSCAN indicates whether the device driver
	automatically scans for devices when loading.
*	CACHEBUFFERS displays the number of cache buffers used.
*	CACHETYPE displays the type of cache you're using
*	DEVICE provides the SCSI ID, LUN, host adapter, device
	type, and number of volumes for an included device.
*	EXCLUDE provides the SCSI ID, LUN, and host adapter of
	an excluded device.
*	LUNSCAN indicates whether the device driver
	automatically scans for SCSI LUNs. This must be ON for
	use with the PD System.
*	NUMDEVICES displays the number of devices that the
	device driver includes.
*	NUMEXCLUDE shows the number of devices that the device
	driver is excluding.
*	PAUSE indicates whether the device driver pauses after
	loading
*	USEEMS indicates whether the device driver is loaded in
	EMS
*	VERBOSE indicates whether the screen displays
	information as the device driver is loading.

2.2	Understanding CD-ROM Caching
------------------------------------

To work with your CD-ROM drives, you require a CD-ROM
extensions program, such as CorelCDX, which interprets the
CD-ROM file system format for the operating system. CorelCDX
also provides caching for CD-ROM data using several types of
caches, which include a path table, directory, and data
cache. As an extension to CorelCDX, CDXCACHE provides an
extended memory data cache.

2.2.1	Loading and Unloading CorelCDX
--------------------------------------

If you installed CorelCDX, it's loaded at startup from your
AUTOEXEC.BAT file using the configuration defined in the
CRLSCSI.INI file. For more information about configuration
settings, see "About CRLSCSI.INI".

If you need to free the memory or drive letters used by
CorelCDX, you can unload CorelCDX. The next time you restart
your system, CorelCDX is loaded again. CorelCDX may not
unload if other TSR programs were installed after CorelCDX
was loaded. If problems occur, unload the other TSR programs
and then try to unload CorelCDX again.

To unload CorelCDX:

Enter the following at the command prompt: CORELCDX /UNLOAD.

Path Table, Directory, and Data Caches:

CorelCDX caches CD-ROM data using path table, directory, and
data caches. The path table cache stores information about
the name and location of each directory on the CD. Each path
table cache buffer accommodates approximately 100
sub-directories.

The directory cache stores information such as the name and
location of the files in each directory on the CD. Each
directory cache buffer accommodates approximately 40 to 50
files.

The data cache stores the contents of recently accessed
files from the CD and any data that's expected to be
required next. CorelCDX uses a read ahead plus least
recently used (LRU) algorithm for its data cache: frequently
used data remains in the cache and infrequently used data is
discarded from the cache. Data is read into the cache in
sector blocks.

The CRLSCSI.INI file includes commands that affect these
caches. For example, commands specify the number of buffers
allocated to these caches. For more information about
CRLSCSI.INI, see "About CRLSCSI.INI".

2.2.2	CDXCACHE: An Extended Memory Cache
------------------------------------------

CDXCACHE, if enabled, is loaded at the same time as
CorelCDX. This cache stores information recently read from
CD-ROM drives in extended memory. When information requested
by an application is located in the cache, the information
can be accessed more quickly than re-reading the information
from the drive. 

CDXCACHE uses a least recently used (LRU) algorithm:
frequently used data remains in the cache and infrequently
used data is discarded from the cache. CDXCACHE works best
with database type applications, which repeatedly read
information from the same areas of a CD.

CDXCACHE can cache the first 16 CD-ROM drives connected to
your system. The cache page size affects the maximum
cacheable sector address.

2.2.3	CDXCACHE versus SMARTDrive
----------------------------------

Both CDXCACHE and Microsoft's SMARTDrive program use
extended memory caching. If you're using SMARTDrive version
5.0 provided with MS-DOS 6.2, you can use SMARTDrive rather
than CDXCACHE. However, CDXCACHE has smaller overhead and
operates faster than SMARTDrive.

SMARTDRV.EXE 5.0 is designed to work exclusively with
Microsoft's MSCDEX CD-ROM driver. However, Corel's
PATCH_SD.COM modifies SMARTDRV.EXE to recognize CorelCDX as
a valid CD-ROM driver.

PATCH_SD creates a copy of the existing SMARTDRV.EXE program
and stores the copy as SMARTDRV.MSC. If you've made changes
to SMARTDRV.EXE version 5.0 that change its size, such as
compressing the file, from 45145 bytes, PATCH_SD won't work.

To modify SMARTDrive to recognize CorelCDX
a)	Enter the following at the command prompt: PATCH_SD.
b) 	Check your AUTOEXEC.BAT file to ensure that CorelCDX is
	loaded before SMARTDrive; otherwise, SMARTDrive won't
	find, and therefore cache, CD-ROM drives. Since
	SMARTDrive is loaded after CorelCDX, you can't use the
	CorelCDX /UNLOAD command.
c)	Use the CorelCDX section of Configuration to set the
	XMS Cache Size option to Disable. The CDXCACHE is
	enabled, by default. If you don't disable the
	cache, both CDXCACHE and SMARTDrive will cache data,
	using twice the necessary amount of extended memory.
d)	Reboot your system to reinstall SMARTDRV.EXE.

2.3	Comparing Information on Two Drives
-------------------------------------------

The XCOMP command compares files and sub-directories on one
drive to files and sub-directories on a second drive. XCOMP
is useful for comparing source files to destination files
after you've written information to a PD cartridge.

To compare files and sub-directories on two drives:

Enter the following at the command prompt: XCOMP [options].

drive1
	Specifies the location of the first set of files you
	want to compare. You must specify a different drive
	letter than drive2 and include the full directory path.
drive2
	Specifies the location of the second set of files you
	want to compare. You must specify a different drive
	letter than drive1 and include the full directory path.
/log
	Specifies the name of a log file in which you want to
	record information generated by XCOMP recorded. You
	must include the full directory path and log file name.

For example, the following XCOMP command compares the files
in C:\BUILD to F:\ and records the results in a log file
named ERRORLOG:

XCOMP  C:\BUILD F:\ /ERRORLOG

