ANSICONV: ANSI <--> DOS Character Conversion
        --------------------------------------------

Introduction
------------
  Most of the .DBF files on this CD-ROM contain both English and
  French text. The French accented characters are represented by
  the ANSI character set, not the DOS character set. ANSI is the
  native character set of Arc/Info and most Windows applications,
  including SurView (which displays the accented characters
  correctly).

The Problem
-----------
  If you attempt to view/edit any of the .DBF files with most
  Microsoft Windows spreadsheet or database programs (i.e. Excel,
  Quattro Pro, Access), you will destroy all of the French
  accented characters. Although these applications are all
  Windows applications, they assume that the .DBF files contain
  only DOS characters (since they are considered to be 'DOS'
  files). Therefore, when ANSI characters are encountered, they
  are unrecognized and are converted to '_' or 'T', depending on
  the application. If you then 'Save' the .DBF file, the file
  will contain the '_' and all of the accented characters will
  have been destroyed.

  Note that some of these applications have an option for ANSI
  or DOS text when importing 'text' files, but there is no such
  option for DBF files.
      
Example
-------
  To illustrate the difference between the ANSI & DOS character
  sets, start up the DOS EDITor and enter the following 2
  characters, by holding down the ALT key while entering the 3
  digits on the numeric keypad. Then release the ALT key:
        ALT 130   "e accent acute" using the DOS  character set
        ALT 233   "e accent acute" using the ANSI character set

  You should see 2 characters:
        'e accent acute' 
        'a theta symbol'

  Now save the file (any name, i.e. XXX.TXT).

  Start up the Microsoft Windows Notepad application and open
  the XXX.TXT file. You will now see 2 different characters:
        'a block'
        'e accent acute'

  This demonstrates that DOS EDIT can display the DOS characters
  correctly, but not the ANSI characters. Conversely, Microsoft
  Windows Notepad can display the ANSI characters correctly, but
  not the DOS characters.

The Solution
------------
  In order to edit or view these .DBF files without destroying
  the accented characters, they must be first translated from
  ANSI to DOS characters, even if you are using a Windows
  application to open the .DBF files.

  In addition to LF <--> CRLF translation, the unix2dos &
  dos2unix utilities can also convert between ANSI (ISO) & DOS
  with the -iso option, but you must NOT use this utility on
  .DBF files, since they have a binary header that must NEVER
  be translated.

  Instead, use the ANSICONV.EXE utility supplied on this CD-ROM
  to convert the files. It can convert .DBF or text files between
  DOS and ANSI character sets.  For text files, it converts all
  characters: for .DBF files, it leaves the header untouched and
  converts the remaining characters.

Procedure to Edit .DBF files
----------------------------
  1. Use the ANSICONV.EXE utility to convert the DBF file from
     ANSI to DOS
  2. Open the DOS DBF file and edit it as you wish
  3. Save the DBF file (you have no ANSI/DOS choice: it will be
     saved using the DOS character set)
  4. Use the ANSICONV.EXE utility to convert the DOS DBF file
     from DOS back to ANSI.

If you have any questions about the ANSICONV utility or the issue
of DOS/ANSI character sets, do not hesitate to contact the
author anytime:
        
                                John A. Grant
                                Earth Sciences Sector
                                Geological Survey of Canada
                                Mineral Resources Division
                                601 Booth St., Room 591
                                Ottawa, Ontario, K1A 0E8
                
                                Phone:  (613) 992-1082
                                FAX:    (613) 996-3726
                                e-mail: jagrant@gsc.nrcan.gc.ca