April 25, 1992

THIS  IS VERSION 3.11b OF DFL. THE ONLY DIFFERENCE BETWEEN THIS  VERSION  AND 
VERSION  3.11a IS A MINOR DOCUMENTATION CHANGE INDICATING A NEW  SUPPORT  BBS 
AND  EMAIL  NETWORK  FOR DFL. THE NEW BBS IS:  TOAD  HALL  415-595-2427.  THE 
NETWORK IS RIME, SHAREWARE CONFERENCE (check with your sysop on how to access 
it). EVERYTHING ELSE IN THIS PACKAGE IS UNCHANGED.


Whats new in DFL version 3.11 since version 3.02:

1. W.S.Ataras  Engineering  is  a  member of  the  Association  of  Shareware 
   Professionals  (ASP). ASP wants to make sure that the shareware  principle 
   works  for you. This software conforms to ASP standards.
2. The  shareware version of DFL no longer has archive support disabled.  The 
   only difference between the shareware and registered versions of DFL are a 
   startup and exit registration reminder screen. All functions are enabled.
3. Registered users receive a printed manual.
4. DFL  now directly accesses recognizable archive file  formats.  Currently, 
   only the ZIP format is recognized. If an archive format is unrecognized or 
   the author changes it, DFL will revert to indirect access. In other words, 
   DFL  is still able to access all archives, but the widely used ZIP  format 
   is now processed far more quickly.
5. Added  "Users'  Question and Answer" section in manual.  This  section  is 
   updated with useful correspondence with registered and non-registered  DFL 
   users. And YES, we're happy to communicate with non-registered users.
6. Rearranged menus slightly for aesthetics.
7. International Language Support.
8. Added F2 print function to file viewing window.
9. Monochrome display improved.
10. Added  '/mono' command-line option to force monochrome colors  for  weird 
    display  adapter/monitor  combinations.  It may also  be  used  with  the 
    installation program.

11. Added the following new scan modes -

   A. Path Mode -

      DFL  will scan your Path (see your dos manual for a description of  the 
      Path)  for duplicate executables. The selected disks and scan mask  are 
      ignored.  Only  files matching *.EXE, *.COM and *.BAT on the  Path  are 
      examined.  As  an example, DFL.EXE, DFL.COM and DFL.BAT  are  duplicate 
      executables that, if in the Path, can cause some frustrating confusion.

   B. FastAlias Mode -

      In FastAlias mode, DFL attempts to locate files with duplicate contents 
      using 32 bit CRCs. That is, files with equal lengths and equal CRCs are 
      assumed to be duplicate. The chances of two files meeting this criteria 
      and having different contents are on the order of 1 in millions.  Under 
      this  mode, files that are determined to be duplicate  are  PRACTICALLY 
      GUARANTEED to actually be duplicate. The benefits of this mode are:

      1. The  files are never actually compared byte-by-byte as in  FullAlias 
         mode (described below). This dramatically decreases the search  time 
         and disk activity.
      2. Very  time-consuming  recursive situations that  occur  in  previous 
         versions of DFL are avoided.
      3. DFL  uses the same 32 bit CRC that is used in ZIP files. This  means 
         that  doing a FastAlias search through ZIP files is incredibly  fast 
         because  CRCs for the archived files are already computed and  files 
         never need to be extracted for a byte-by-byte comparison.

   C. Changed the old Alias mode to FullAlias Mode -

      In FullAlias mode, DFL attempts to locate files with duplicate contents 
      by performing byte-by-byte comparisons of the contents of equal  length 
      & CRC files. Under this mode, files that are determined to be duplicate 
      are  GUARANTEED to actually be duplicate. This mode is essentially  the 
      same as FastAlias (described above) with the addition that the contents 
      of two files are compared after the length and CRC are determined to be 
      equal. The benefits of this mode are:

      1. Because  of  the  CRC layer, DFL knows ahead  of  time  which  files 
         actually  need to be compared and thus, performs fewer  comparisons. 
         Previous  versions of DFL took the John Wayne approach and  compared 
         all equal length files. Users of older versions of DFL should notice 
         a dramatic speed improvement in their Alias searches.

      2. Unlike  the  1-in-millions possibility  under  FastAlias,  duplicate 
         files found by FullAlias are GUARANTEED duplicate.