Bulletin #10 rev. 03/30/93

How to use PKZIP and PKUNZIP

  PKUNZIP is the program that reconstructs or extracts compressed files.
  In addition to reconstructing a complete ZIP file, it can selectively
  release individual files, show files on the screen for fast viewing, or
  print them out on a printer.

       A ZIP FILE holds file information that has been reduced in size for
       better storage.  It is sometimes called a compressed file or a
       library file.

       A ZIP FILE can be made up of either one or more files compressed
       and stored together under one file name.
   |                                                                    |
   |        A ZIP file contains one or more files.                      |
   |                                                                    |
   |    MANUAL.ZIP  contains -->  chap1.txt  toc.txt  app.txt  cov.txt  |
   |                                                                    |
   |    BIG.ZIP     contains -->  Huge.Wks                              |
   |                             This is a very large worksheet that    |
   |                             has been shrunk in size for better     |
   |                             storage and faster telecommunications. |

       FILE RECONSTRUCTION  or  FILE EXTRACTION  refers to the process of
       recreating files that have been previously compressed.


  PKware works BEST on a hard disk system.

   1.  Even though you are making files smaller, the process used to shrink
       them can BRIEFLY DOUBLE the storage space needed.  When a ZIP file is
       being modified (e.g. files being added), the process creates a new
       ZIP file which will be used as a REPLACEMENT for the old version.
       Both the OLD and the NEW versions will be on your disk until just
       prior to the completion of the process.

   2.  When you reconstruct a ZIP file, the amount of space needed to
       hold that file can double.  A large hard disk drive normally insures
       that enough storage area is available.

       Many compressed files are stored on floppy disks.  The limit to
       floppy storage is the number of characters your floppy system will

	    Standard double density floppy     360K
	    High density floppy                1.2 meg
	    3-1/2" floppy                      .7 or 1.4 meg

       You may have problems either ADDING files to a ZIP file stored on a
       floppy disk, or reconstructing files to a floppy disk system when
       the number of characters in the ZIP file is more than 50% of the
       available storage space on the floppy disk.

  Consider a standard floppy disk system:
     |                                                                  |
     |               Standard Floppy Disk Drive of 360K                 |
     |                                                                  |
     |  A:> BIGFILE.ZIP  has 250,000 characters                         |
     |                                                                  |
     |           1.  In order to ADD files to BIGFILE.ZIP, you need     |
     |               500,000 of space.  The extra space is used to      |
     |               hold a NEW updated ZIP file created BEFORE the     |
     |               old ZIP file is deleted.                           |
     |                                                                  |
     |           2.  When BIGFILE is reconstructed it might require     |
     |               400,000 of space, but the available space on the   |
     |               disk restricts it to 360,000.                      |

       There are a number of ways to avoid the limitations.  A thorough
       knowledge of PKware Programs will show you how to:

       1.  Selectively reconstruct files from a ZIP file.  Instead of
	   extracting everything at once, you can view file size information
	   and then select SPECIFIC files to be reconstructed to a floppy.

       2.  If you have two floppy drives, create the ZIP file file on your
	   second disk drive so that you have the full 360K available to you.

       3.  Use the special  -b  command option, which routes the NEW file to
	   an alternate disk drive during the compressing process then copies
	   it back to the floppy disk upon completion.

   1.  PKware programs MUST be located in:
       A.  The drive you are working on, OR . . .
       B.  Any directory accessible through the PATH= setting.
	   C:> PATH=C:/Utils
	   In this example, PKware is in the Utils Directory.  The computer
	   will find and execute the program even though you are in a
	   different directory or drive because any commands entered will be
	   run through the PATH.  Consult your MS-DOS documentation for more
       C.  Any directory through the use of PATH notation if you are using
	   MS-DOS 3.0 or later.
	   C:>B:PKZIP  -a  OldFile.ZIP  *.*     PKZIP is located on the
						B:> drive
	   C:>\UTILS\PKZIP  -v  Stuff.ZIP       PKZIP is located in \UTILS
						as indicated in the PATH
   2.  All PKware program commands are typed at the prompt.
   3.  Typed information can be in CAPS, lower case, or a mixture.
   4.  The DEFAULT is  *.*  or ALL FILES when specific files are not named
       (except for the  -d  delete files option).
   5.  It is NOT necessary to type the extension  .ZIP  when processing a
       ZIP file, it will be assumed.  The extension is used in this
       documentation for clarity.
   6.  A help screen is displayed when you type the program name at the
       prompt then press .  Also typing  -h  on the command line
       will call up the help screen.
	      C:>PKZIP      enter       gives you HELP
	      C:>PKUNZIP    "            "    "    "
   7.  The notation  PKUNZIP *  or  *.ZIP  will reconstruct all ZIP files
       within the given area.
   8.  During the reconstructing process, the notation *.* will tell
       PKUNZIP to attempt to reconstruct ALL files whether they are ZIP
       files or not.  This would waste time, but will not damage any files.
   9.  The default area for the temporary second ZIP file that is created
       while the original is being updated, is the same path and directory
       location as the original ZIP file.  As this can cause a space
       shortage on a floppy disk, the -b option is recommended.  (See
       Section 3)
  10.  The compressing function will STOP if specific, pre-specified files
       are not found.
  11.  All MS-DOS file handling procedures can be used:
		 Filename.ext          Full file name designations
		    *Name.ext          Names with wild card markers
							SUPER QUICK |
	      QUICK START- Extracting a File from a BBS             |
			  Use of PKware in Telecommunications -