
                 QCDROM -- DOS CD and DVD Disk Driver, V4.2
               ==============================================

1. Description
   -----------

   QCDROM is a DOS driver for CD and DVD drives.   It is for use on normal
   PC system IDE channels, including 1997 or later PC mainboards that have
   Intel/VIA/SiS/ALi or similar UltraDMA controller chips.   QCDROM is NOT
   for SCSI, Serial-ATA, or "add-on" UltraDMA cards by Promise, SiiG, etc.
   QCDROM handles normal mainboard IDE channels, with or without UltraDMA,
   avoiding a need for "add-on" cards!

   QCDROM runs from 1 to 3 CD/DVD drives.   On loading, it checks both IDE
   channels, in order from primary-master to secondary-slave, and runs the
   first three CD/DVD drives found.   It has switch options (see below) to
   specify the "driver name" and request testing of specific IDE units for
   CD/DVD drives, instead of checking all units in "IDE order".   Both old
   "PIO mode" and new UltraDMA CD/DVD drives may be used.   QCDROM handles
   file-input requests issued by SHCDX33C, MSCDEX, etc.   It also supports
   all DOS "audio" requests and can "play back" an audio CD.

   QCDROM runs only the IDE channels at their normal I-O address ranges of
   01F0h-1F7h (primary) and 0170h-177h (secondary).    The old "alternate"
   addresses of 01E8h-1EFh (primary) and 0168h-16Fh (secondary) can be set
   using its /A switch.   QCDROM does not use interrupts and does standard
   "PIO mode" data input when no UltraDMA controller is found.   This lets
   QCDROM work with older mainboards or with pre-1997 "plug-in IDE" cards.

   QCDROM can set a local stack, does an 80386+ test and I-O timeout tests
   and has other items to make the driver SAFE!    QCDROM takes 2528 bytes
   of memory with its local-stack or 2016 bytes without a stack.    An XMS
   buffer is recommended, to avoid "PIO mode" data input.    When the QDMA
   driver loads first, QCDROM can "share" QDMA's XMS buffer, or QCDROM can
   set its own if 128K of XMS is free.   XMS or "PIO mode" is used only as
   needed -- QCDROM does UltraDMA input whenever possible, for best speed!

   V4.2+ QCDROM is updated to detect the V3.8 QHIMEM driver.   V4.8 QCACHE
   has been similarly updated.   Old versions should not be mixed with the
   newer drivers.

   *** NOTE ***
     Due to incessant, unfavorable posts on FreeDOS forums, this driver is
     PROHIBITED from use with FreeDOS and will now ABORT if loaded in that
     system.   Using this driver in all other DOS systems (MS-DOS, EDR-DOS
     etc.) is still supported and is unaffected.


2. NO Warranty
   -----------

   QCDROM is offered as free software, "as is" and "use at your own risk",
   and WITHOUT any warranty,  not even the implied warranties of MERCHANT-
   ABILITY nor of FITNESS for ANY particular purpose!

   QCDROM questions may be addressed to Johnson Lam at <johnson@tmfc.net>.
   The author of QCDROM in the U.S.A. will try to reply and to keep QCDROM
   working O.K.


3. Revisions
   ---------

   V4.2  14-Jan-07  QCDROM updated to work with V3.8+ QHIMEM.

   V4.1  10-Jan-07  QCDROM corrected to post "no disk in drive" status.
   V4.0  29-Dec-06  QCDROM works again in VMWare!   Many Thanks to Erwin
                      Veermans for his help!
   V3.9   8-Dec-06  Corrected a load-time ERROR in QCDROM.
   V3.8   6-Dec-06  Using QCDROM with FreeDOS is now PROHIBITED!
   V3.7  12-Nov-06  QCDROM "A20 line" handling corrected.
   V3.6   9-Nov-06  QCDROM stack increased.
   V3.5   2-Nov-06  QCDROM /I switch added, to avoid "odd" BIOS trouble.
   V3.4  24-Oct-06  QCDROM updated for QXHIMEM.   V3.3 changed DELETED!
   V3.3  15-Oct-06  QCDROM no longer requires XMS memory with UMBPCI!
   V3.2  11-Oct-06  QCDROM now has a /X switch and can omit its stack.
   V3.1   1-Oct-06  Added QCDROM /A switch for alternate EIDE addresses.

   V3.0  21-Sep-06  QCDROM now handles the Intel 82801EB chipset!
   V2.9   8-Sep-06  QCDROM revised for the no-overlap V3.2+ QDMA/QDBOOT.
   V2.8  15-Aug-06  QCDROM now reserves its own XMS memory, when needed.
   V2.7   7-Aug-06  QCDROM updated to support V3.0 QHIMEM and QHIMEM2.
   V2.6  11-Jul-06  QCDROM updated for fast V2.8+ QHIMEM XMS moves.
   V2.5   8-Jul-06  QCDROM now loads in UMBPCI upper-memory and uses PIO
                      mode as needed, if QDMA sets only one XMS buffer.
   V2.4  30-Jun-06  QCDROM now has "Int 13h" logic to locate QDMA.   XMS
                      buffers assigned one per driver, not per channel.

                    [V2.2 and V2.3 were never used by QCDROM].

   V2.1  23-Jun-06  QCDROM updated to work with V2.3+ QDBOOT.
   V2.0  30-Apr-06  QCDROM/QDMA "linkage" revised to support EMM386.

   V1.2  16-Mar-06  QCDROM loads in UMBPCI upper-memory with V1.4+ QDMA.
   V1.1   8-Mar-06  QCDROM "shares" QDMA's XMS buffers and runs 3 units.
   V1.0  20-Feb-06  Original release.


4. Switch Options
   --------------

   QCDROM switch options are as follows:

      /A    Requests use of the old alternate EIDE controller addresses,
              01E8h-01EFh on the primary channel, and 0168h-016Fh on the
              secondary channel.   If /A is omitted, the driver will use
              normal controller addresses of 01F0h-01F7h or 0170h-0177h.
              /A is only for an "odd" SATA BIOS or other unusual cases.

      /D:   Specifies the desired "device name" which SHCDX33C or MSCDEX
              will use during their initialization to address the CD/DVD
              drives.   Examples are:  /D:CDROM1  /D:MYCDROM  etc.   The
              device name must be from 1 to 8 bytes valid for use in DOS
              filenames.   If /D: is omitted, or the "device name" after
              a /D: is missing or invalid, QCDROM1 will be the default.

      /I    Forces "independent" driver setup.   QCDROM requests its own
              XMS buffer and does NOT test if QDMA is loaded.   An "odd"
              BIOS may mishandle the special QCDROM call to locate QDMA!
              For systems not using the QDMA driver, /I may be needed to
              avoid drive-select or other "odd" BIOS errors!   /I is not
              needed if /UX is also given.

      /L    Limits DMA to memory below 640K.   /L is REQUIRED for UMBPCI
              or other drivers whose upper-memory cannot do DMA.    When
              QCDROM itself loads with /L in upper-memory, XMS memory is
              required to issue DMA command-lists, or QCDROM will ABORT!
              Without /L or if QCDROM is in low memory, XMS is optional.
              /L makes QCDROM use its XMS buffer for input of data above
              640K.   "PIO mode" will handle such requests if XMS is not
              available or is unwanted due to QDMA's /B switch.    /L is
              IGNORED, and XMS is not needed, if /UX is also given.

      /PM   Requests the driver to check the IDE primary-master unit for
              a CD/DVD drive during driver init.    If a CD/DVD drive is
              NOT found as primary-master, driver loading will ABORT!

      /PS   Same as /PM but tests the primary-slave unit only.

      /SM   Same as /PM but tests the secondary-master unit only.

      /SS   Same as /PM but tests the secondary-slave unit only.

            --- NOTE ---
              For 2 or 3 drives, multiple  /PM /PS /SM /SS  switches are
              allowed.   The first-specified drive is addressed as "unit
              0", the second as "unit 1", etc.    If fewer switches than
              drives are given, unreferenced drives will be UNUSED.   If
              NO drive switches are given, QCDROM will "scan" for CD/DVD
              drives from primary-master to secondary-slave.   The first
              drive found will be "unit 0", the second "unit 1", etc.

      /UF   Enables "Fast DMA".   I-O requests which cross UltraDMA "64K
              boundaries" use two-part DMA, for data up to the boundary,
              and for data beyond it.    I-O which is misaligned (not at
              an even 4-byte address) will go through QDMA's XMS buffers
              if available or will use "PIO mode" otherwise.

            --- NOTE ---
              Despite UltraDMA specs, NOT ALL chipsets or mainboards run
              "Fast DMA" properly!   /UF must be TESTED on every system!

      /UX   Disables ALL UltraDMA, even for CD/DVD drives capable of it.
              QCDROM then uses "PIO mode" for all commands.   /UX is not
              usually needed and is mainly for tests or diagnostic work.

      /X    Causes no local-stack to be set.   This saves 512 bytes when
              SHCDX33C is used, as QCDROM can run on the SHCDX33C stack.
              /X must NOT be given if SHCDX33C will not be used!

   For each switch, a dash may replace the slash and lower-case characters
   may be used.


5. Setup and Configuration
   -----------------------

   QCDROM is loaded by the CONFIG.SYS file, which must have a command line
   similar to:

            DEVICE [HIGH] = [path] QCDROM.SYS [/D:DeviceNm] [...]

   Examples:   DEVICE=C:\DOS\QCDROM.SYS

               DEVICEHIGH=C:\BIN\QCDROM.SYS /D:CDROM1 /UF /L /X /SM /SS

   If QCDROM is to share QDMA's XMS memory, the QDMA driver must be loaded
   first.   When QDMA is not used, QCDROM may be loaded at any time.


6. Error Reporting
   ---------------

   QCDROM reports an I-O error to its "CD-ROM redirector" program the same
   as all other DOS CD/DVD drivers.    For full details, see the Microsoft
   "MS-DOS CD-ROM Extensions 2.1", which includes information about CD/DVD
   device drivers for use with SHCDX33C or MSCDEX.


7. SPECIAL NOTES
   -------------

   Some CD/DVD drives (Sony, etc.) DO NOT follow all ATAPI "standards" and
   may require DISABLING UltraDMA with the /UX switch!

   Be sure to "enable" your CD/DVD drive(s) with the BIOS set-up routines!
   A drive that is "disabled" may cause the BIOS to clear all its UltraDMA
   flags and leave the drive in "PIO mode" zero, which is terribly SLOW!

   When cabling a CD/DVD drive by itself to an IDE channel, note that both
   "ends" of the cable must be used, NOT one end and the middle connector!
   This prevents ERRORS, as an unused cable-end can pick up "noise" like a
   RADIO antenna!

   If the driver "scans" for CD/DVD drives to use, error events WILL occur
   (select error, not a CD/DVD found, etc.).    Such events cause that IDE
   unit to be ignored.   When an actual CD/DVD drive is ignored, users can
   add the appropriate  /PM /PS /SM /SS  switch for that drive to QCDROM's
   line in the CONFIG.SYS file, then re-boot.    Specifying a drive-select
   switch always causes errors for that drive to be displayed.

   If no CD/DVD drives are found, QCDROM displays "No CD/DVD drive to use;
   QCDROM not loaded!" and aborts.   But note that some BIOS programs will
   NOT "configure" mainboard UltraDMA chips when they find no IDE devices!
   Users who get the above message must first verify that the CD/DVD drive
   is "enabled" through the BIOS set-up routines.   If this HAS been done,
   "No CD/DVD drive to use" says the UltraDMA chip is NOT set for "legacy"
   IDE addresses (1F0h/170h, 1E8h/168h) and the BIOS might need an UPDATE!
   Note also that QCDROM does not support "Native PCI mode" UltraDMA chips
   ("servers"), only chips set to "Legacy IDE mode".

