                       XtraDrive README.TXT file
                         Last Updated: 4/29/93
       (c) Copyright 1993, Integrated Information Technology, Inc.

     XtraDrive is a trademark of Integrated Information Technology, Inc
  All other trademarks are trademarks of their respective companies and are
                used for identification purposes only.
     __________________________________________________________________

                         CONTENTS OF README.TXT
     Sections                                              Line numbers
     ========                                              ============
     Other non-supported hardware / software                    51

     XtraDrive procedures
     ... INSTALL
     ...... What does the INSTALL program change?               62
     ...... DR DOS 6.0 password protection                      86
     ...... If you are updating from an earlier XtraDrive       95 
     ... Operation
     ...... What is the largest compressible hard drive?       111
     ...... Why does physical space by XDIR and VMU differ?    118
     ...... XDIR doesn't operate as in manual. Why?            126
     ...... Using XtraDrive on device driven hard drives only  134
     ... XFORMATed media
     ...... Norton Disk Doctor                                 150
     ...... DOS BACKUP.EXE / Backup programs                   160
     ...... XFORMAT combinations that don't work               172
     ...... Universal XtraDrive with Windows 32-bit access     181
     ... New utility - XADJUST                                 188

     Common DOS procedures
     ... A definition of a backup                              223
     ... FDISK with XtraDrive running (advanced users)         235
     ... News on the latest anti-virus softwares               242
     ... News on the latest cache softwares                    248
     ... MS-DOS 6.0 Upgrade                                    257
     ... Using the Norton Emergency Disk (advanced users)      267

     Special hardware notes
     ... Syquest removable media drives                        276
     ... Quantum Passport removable hard drives                288

     Optimizing XtraDrive performance (advanced users)         297

     Other manufacturers' software products
     ... Quarterdeck's QRAM for 286 computers                  355
     __________________________________________________________________
  
 
Other non-supported hardware / software
---------------------------------------
... Hardware
...... IBM XT type hard drive controllers for IBM 8086/8088 processor 
       based computers.
...... Systems that can't boot from a floppy diskette.
... Software
...... Memory Commander
...... PC Watchman


What does the INSTALL program change in configuration files?
------------------------------------------------------------
... Changes to C:\CONFIG.SYS:
    The INSTALL program adds the XtraDrive device line to the end of
       the file C:\CONFIG.SYS.  Usually this looks like:
       DEVICE={drive letter:}\XTRADRV\xtradrv.sys
       If you are installing on a device driven hard drive, INSTALL also
       adds the drive letter of the drive, for example:
       DEVICE={drive letter:}\XTRADRV\xtradrv.sys E:
    If you have QEMM386, INSTALL adds an exclude statement, typically
       'x=8000-a000' to the end of the QEMM386.SYS line.
    If you have 386MAX, INSTALL adds a NOLOW statement to the end of the
       386MAX.SYS line.

... Changes to C:\AUTOEXEC.BAT:
    Adds {drive letter:}\XTRADRV to first path statement.

... Changes to \Windows\SYSTEM.INI:
    SET 32BITACCESS=OFF

... Changes to the partition type:
    From a DOS type (typically BIGDOS or FAT-16) to IIT's (NONDOS) type.


DR DOS 6.0 password protection
------------------------------
    If the XtraDrive INSTALL program complains of not being able to 
install on the boot drive because it is being controlled by a program 
that appropriates INT13, check to see if DR DOS 6.0 password protection 
is enabled.  If so, disable it for the INSTALL procedure.  Re-enable after 
INSTALL is done.


If you are updating from an earlier XtraDrive 
---------------------------------------------
    (1) Disable all anti-virus programs running (in memory) including
MR BIOS and AWARD BIOS anti virus programs.

    (2) Insert the update disk (disk 2 of 2) in a floppy drive. If the 
update disk is in drive A: type:
        A: <Enter>
If in drive B: type:
        B: <Enter>

    (3) Type UPDATE <Enter>

    (4) After system re-starts, re-enable anti-virus software.
          

What is the largest compressible hard drive?
--------------------------------------------
    The limit to the size of physical hard drive partition XtraDrive 
can compress is the largest size your version of DOS can handle.  For 
MS-DOS 5.0 that's 2 gigabytes.  


Why does physical space by XDIR and VMU differ?
-----------------------------------------------
    XDIR is meant to run at the speed of normal DOS DIR and so does a 
quick simple check of physical space not including space taken up by 
previously deleted files.  VMU does a more accurate calculation but
takes longer.  


XDIR doesn't operate as in manual. Why?                 
---------------------------------------
    If XDIR doesn't seem to operate as specified in the XtraDrive manual,
you may be running XDIR from DR DOS by mistake.  Edit your
C:\AUTOEXEC.BAT file and place {drive letter:}\XTRADRV ahead of DRDOS in
your PATH statement.


Using XtraDrive on device driven hard drives only
-------------------------------------------------
    If XtraDrive is installed on device driven hard drives only and not on
any fixed hard drives, the following conditions exist:

    (1) Updating to later versions of XtraDrive version 3.0 only requires
copying the new files to the hard drive directory of XtraDrive.  For
example, if the update disk were in the A: drive and the XtraDrive
directory is C:\XTRADRV, type:
    copy a:\*.* c:\xtradrv

    (2) Running VMU-Advanced options (only) will report "global data not 
found." This is a valid statement for systems that don't have XtraDrive 
installed on fixed hard drives.


Norton Disk Doctor
------------------
    Norton Utilities' Disk Doctor program does not understand why our
FAT (file allocation table) for XFORMATed floppies is smaller than a
normal DOS floppy's FAT.  DOS CHKDSK and PC Tools' Diskfix programs 
should work fine to repair any problems found on an XtraDrive XFORMATed
floppy disk.  Norton Utilities' Disk Doctor should work fine on other 
XFORMATed removable media besides your standard A: and B: floppy disks.


DOS BACKUP.EXE / backup programs with XFORMATed floppies
--------------------------------------------------------
    XFORMAT formats a floppy disk to be a certain logical size.  
Whether the data will compress to that ratio is questionable without
checking the files first with XDIR.  Even then, on a multiple floppy 
backup, a particular file that takes up the majority of space on a 
single floppy may not compress well, causing the backup process to prompt
for a new disk. Back-up programs from Central Point, Norton Utilities and
Fastback should not be an issue as they re-write all formatting
information, making an XFORMATed floppy in essence a normal floppy disk.


XFORMAT combinations that don't work
------------------------------------
... XFORMAT /BOOT will not make a valid XtraDrive boot floppy on a floppy
    disk that has already been compressed by XFORMAT.

... XFORMAT /U /BOOT doesn't always work reliably, depending on the 
    machine being used.  Format the disk first using standard DOS format.


Universal XtraDrive with Windows 32-bit access
----------------------------------------------
    There may be process hang if XTRADRV.COM is initiated in a DOS shell
under Windows 3.1 running 32-bit disk access.  Initiate XTRADRV.COM 
before starting your Windows session in this case.


New utility - XADJUST
---------------------
    XtraDrive installs with a default compression ratio of 2 to 1, a 
higher compression ratio if the user desires.  This estimate may not be 
achieved, depending on the type of data being compressed (see Chapter 2: 
Estimating a compression ratio).  If the average compression ratio 
reported by VMU is less than the compression ratio you installed with 
and you are running out of physical space, you may use the XADJUST 
utility to make the logical space available match your average 
compression ratio more closely.  Xadjust works by reducing the logical 
bytes available on an XtraDrive secondary drive.  This procedure may 
take several minutes on very large hard drives. 

To XADJUST the size of a drive, type:
    xadjust  {drive letter:}  ratio  

where ratio is a value between 1.00 and the compression ratio you 
INSTALLed with, in increments of .05. For example:
    xadjust c: 1.95

    If an XtraDrive primary drive is entered for {drive letter:}, XADJUST 
will still reduce the space available on the XtraDrive  secondary drive.  
If there isn't enough space available on the drive for XADJUST to achieve 
the desired compression ratio, XADJUST will report the space it needs in 
bytes.  For example, if you have a 100Mb drive and use a ratio of 1.50, 
the secondary drive must have a maximum capacity of 50Mb.  Therefore, if 
you already have over 50Mb of data on the secondary drive, Xadjust cannot 
achieve a ratio of 1.50. Move or delete files from the drive in question 
to free up these bytes.

To disable XADJUST, type: xadjust {drive letter:} /u
To check the XADJUSTed ratio for a drive, type: xadjust {drive letter:}
XADJUST will also adjust the physical volume size of XFORMATed media.


A definition of a backup
------------------------
    One usable definition of a backup is: sufficient data to get back 
to the point you started at.  If the idea of backing up your entire hard 
drive is too daunting, consider at least backing up all the files you
don't already have on other media.  For example, if you have Microsoft
Word for Windows on installation diskettes, it may not be as necessary
to back up the program as the reports you created with the program.
Please note: we are not recommending that you don't make a backup of 
your system.


FDISK with XtraDrive running (advanced users)
---------------------------------------------
    For partition table entry changes made with DOS FDISK.EXE to be 
effective XtraDrive must not be controlling a hard drive.  Boot from a 
floppy disk if necessary to bypass XtraDrive.


News on the latest anti-virus softwares
---------------------------------------
... PCRX anti-virus may cause VMU not to run.  Disable PCRX from booting
or boot from your XtraDrive boot floppy to run VMU.

  
News on the latest cache softwares
----------------------------------
... Q-CACHE from Qualitas, Hyperdisk
    These may cause XtraDrive utilities not to run or cause VMU to
report "Control area unreadable."  Disable these cache programs or boot to
your XtraDrive boot floppy diskette to run XtraDrive utilities.  Contact
IIT for an updated version to address this issue.


MS-DOS 6.0 Upgrade
------------------
    We have tested with MS-DOS 6.0 and have found all functionality,
including setup and uninstal, to be compatible with XtraDrive.  We do not
recommend running XtraDrive in conjunction with doublspc as using two
data compression products causes unnecessary overhead and does not improve
compression performance. Note: MS-DOS 6.0 does not automatically install 
doublspc: you must install it manually after updating your DOS version.


Using the Norton Emergency disk (advanced users)
------------------------------------------------
    Do not use the Norton Emergency disk to replace the boot sectors of
your hard drives unless XtraDrive is running and you have access to all
compressed drives.  If these conditions do not exist and you wish to
replace the boot sectors of your system, consider contacting IIT 
technical support.


Syquest removable media drives
------------------------------
    Syquest removable media drives have the unique ability to present
themselves as normal INT13 hard drives (non-removable) when a Syquest
disk is inserted while booting the system.

    As the Syquest drive can change functionally, it may also change
the drive letter assigned to it.  We recommend you be consistent
with starting the system either with or without a disk inserted in the 
Syquest if you have other device driven drives on your system.


Quantum Passport removable hard drives
--------------------------------------
    The hard drives are a special case as they are designed to be removed
and interchanged between systems.  If you plan to install XtraDrive on the
second drive (a Passport drive) of your system, you must move the first 
drive as well when going to another system.  If you install on the boot 
drive and it is a Passport drive, it should work fine on other systems.


Optimizing XtraDrive performance (advanced users)
-------------------------------------------------
    The steps in this section may result in some minor performance
enhancements to your system.  It is intended for users who understand
DOS conventional memory (640K), disk caching, EMS and XMS memory,
Windows temporary and Windows permanent swapfiles.

... Conventional memory
    Load XtraDrive high unless you have a bus-mastering (usually) SCSI 
controller.  This will take up 0 Kbytes of conventional memory (0 to 640K)
allowing the user to run the most programs.  See Appendix C of you
XtraDrive v3.0 manual for details on how to do this.

... XtraDrive internal cache settings
    As a general rule, use the highest conventional cache setting you can
while still being able to load XtraDrive into high memory.  If you are not
loading XtraDrive into high memory, use the highest conventional cache
setting you can while still being able to run the program you use that
takes the most conventional memory.  Using larger conventional cache
settings uses 16K more conventional memory per block.  If XtraDrive is
loaded high, the conventional cache will be loaded high also.

    Why use EMS? - Use EMS cache when you need a driver size smaller than
47K and already have EMS memory set aside for another program.  If you are
using XtraDrive's EMS cache, the driver will take up 16K less conventional
memory.  If used at all, the recommended setting is the maximum of 20
16K blocks which is approximately 320 Kbytes of EMS memory.  Remember that
to use EMS memory you must have your memory manager (such as EMM386,
QEMM386, and 386MAX) configure it for you.  EMS memory is usually
difficult to set up on a 286 machine.

... Other cache settings
    Using other cache software in conjunction with XtraDrive's cache is
generally not redundant as the two are caching at different levels.  If
you are using Microsoft Windows, you should keep in mind that any XMS 
memory assigned to a cache will not be available to Windows, causing more
swapfile access and slowing the system down (with or without XtraDrive
installed).

... Defragmentation
    Defragment your drives as often as you would without XtraDrive
installed.  The XtraDrive RECLAIM utility is similar to the clearing
unused file space feature of other defragmentation utilities.

... Microsoft Windows swapfile: temporary or permanent?
    Generally, you should use a permanent swapfile as access to a
permanent swapfile is faster and Windows start-up and exiting of Windows
is not slowed by the creation and deletion of the temporary swapfile.  
A temporary swapfile also promotes fragmentation of your hard drive.

    Microsoft Windows swapfile: compressed or uncompressed?
    If your system is very dependent on the Windows swapfile for memory
(you have 4Mb or less of RAM and are using memory hungry applications
like large spreadsheet or desktop publishing programs), experiment with 
the FREEZE utility to make the permanent swapfile uncompressible as 
instructed in the XtraDrive manual, chapter 4.


Quarterdeck's QRAM for 286 computers
------------------------------------
    When installing Quarterdeck's QRAM memory manager for 286 computers,
the user may encounter issues similar to those caused by QEMM386.  See 
Appendix C for more information. 
