CORELCDX.TXT Driver File Contents (

Driver Package File Name:
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 CorelSCSI version 1.1 uses CORELCDX.COM for its CD-ROM
 extensions. Previous versions of CorelSCSI used MSCDEX.EXE.
 The following syntax shows all the switches available for the
 CorelCDX statement:

      CORELCDX  /D:<driver_name>  /M:<mem_bufs>  /L:<drive_letter>
      /E  /FILES: <num>  /CACHE:<pt>;<dir>;<data>
      /DATABLK:<blk_val>  /E:<emm_val>  /STACK [:<stack_size>]

 Note: The installation adds the default CorelCDX statement
       to your AUTOEXEC.BAT file. However, if you've already installed
       MSCDEX, the installation adds the CorelCDX code to your
       system, but doesn't replace MSCDEX in your AUTOEXEC.BAT file. 


 The following MSCDEX command line switches
 are compatible with CorelCDX version 1.0.

 /D:<driver_name> -- identifies the name of the CD-ROM device driver 
 to be used. You can enter more than one /D:<driver_name> switch to 
 identify multiple CD-ROM device drivers. Names you enter must match 
 names used in the /D:<device_name> parameters for each device 
 driver entry in the CONFIG.SYS file.

 /M:<mem_bufs> -- specifies the approximate number of sector
 buffers allocated. Using a predetermined formula, the total number
 of sector buffers is divided among the path table, directory, and 
 data cache.  Minimum, maximum, and alignment requirements may 
 require that the actual number of buffers may differ slightly from 
 those you specify. See the related discussion about the /CACHE 

 /L:<drive_letter> -- forces CD-ROM drive letter assignment to
 begin at a particular drive letter if you have software
 that requires that your CD-ROM drive be assigned a specific
 drive letter. If that drive letter is not available, CD-ROM 
 drives are assigned from the next available drive letter.

 /E -- uses expanded memory for the cache buffers if it's available.
 Expanded memory is allocated in blocks. To make the most
 efficient use of allocated memory, this switch may slightly
 increase the number of specified cache buffers.  See the
 related discussion about the /E:<emm_val> switch.


 The following command line switches are specific to CorelCDX. 

 /FILES: <num> -- specifies the number of CD-ROM files that
 you can open at the same time. Each file requires approximately
 16 bytes. By default, the limit is the number specified by the
 FILES= line in the CONFIG.SYS file.

 /CACHE:<pt>;<dir>;<data> -- specifies the number of cache blocks
 to allocate for the path table cache, directory cache, and data 
 cache. Each block requires 2K.
 The path table cache stores information about the name and 
 location of each sub-directory on the CD. Each (2K) 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 sub-directory on the CD.
 The data cache stores the most recently accessed contents
 of files on the CD.
 When you specify the number of sector buffers using the 
 /M:<mem_bufs> switch, the <mem_buf> value is divided among the 
 path table, directory, and data cache using a predetermined formula. 
 You can use the /CACHE:<pt>;<dir>;<data> switch to fine-tune the 
 allocation of cache blocks.

 When adjusting the allocation of cache blocks, you can't exceed
 the following minimum and maximum sizes for each area.

      path table cache: block size= 1 sector
                                min= 2 sectors
                                max= 64 sectors

      directory cache: block size= 1 sector
                                min= 2 sectors
                                max= 64 sectors

      data cache: block size= 2 sectors
                                min= 1 block (If you use /DATABLK to alter
                                        the block size, the minimum sectors change.)
                                max= 64 sectors

 When using expanded memory for cache buffers, certain
 internal alignment requirements are enforced. You can't
 change these requirements.

 Note: The /CACHE: and /M: switches are mutually exclusive. 
       If you use both switches, the /M: switch is ignored.

 /DATABLK:<blk_val> -- adjusts the number of 2K sectors 
 assigned to each data cache block. Valid values are 1, 2, 4, or 8.
 The default is 2. This option is useful for applications that
 read data from a CD in contiguous segments.

 CorelCDX uses a read ahead plus least recently used (LRU) algorithm 
 for its data cache. Data read into the cache is read in blocks. 

 Setting the data block size to 1 disables read-ahead 
 caching, but an additional 4K of conventional memory is 
 required. Also, note that the read-ahead caching logic internal of some 
 CD-ROM drives is adversely affected by changing the default data 
 cache block size.

 /E:<emm_val> -- extends the basic MSCDEX compatible /E switch by 
 allowing you to force CorelCDX to use expanded memory, if it's 
 available, for code, data, or cache buffer storage.  The valid 
 <emm_val> options are:
      1 = code/data ONLY in expanded memory
      2 = cache blocks ONLY in expanded memory, the same as /E switch
      3 = code/data AND cache blocks in expanded memory

 When expanded memory is used for code and data, only a small 
 'foot-print' (less than 2K) 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.

 If cache buffers are located in expanded memory, a small amount 
 of conventional memory may also be allocated for storage of 
 required tables. Also, to make efficient use of 
 expanded memory, and due to internal cache alignment requirements,
 the number of cache blocks in use may be adjusted slightly when 
 this option is used.

 /STACK [:<stack_size>] -- causes CorelCDX to switch to its own 
 internal stack while processing software interrupts, rather than 
 using the calling programs stack. Use the <stack_size> variable
 to change the stack from its default size of 512 . For example,
 /STACK:1024 causes a 1K stack to be used, while /STACK:256
 causes a 256 byte stack to be used.


 The following MSCDEX command line switches
 are not supported under CorelCDX version 1.0.

      /V - verbose mode to display information during boot up

      /S - patch to allow sharing of CD-ROM drives on
           MS-NET based servers

      /K - force selection of shift-JIS Kanji Supplemental Volume
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