Apple II
File Type Notes
_____________________________________________________________________________
                                                  Developer Technical Support

File Type:         $E0 (224)
Auxiliary Type:    $8006

Full Name:     EZ Backup Saveset document
Short Name:    EZ Backup Saveset document

Written by:    Peter Easdown and Matt Deatherage               September 1990

Files of this type and auxiliary type contain savesets as produced by 
EZBackup.
_____________________________________________________________________________

EZ Backup is a backup utility that runs under GS/OS.  It provides the ability 
to backup to either a removable block device or to files under any available 
file system.

For more information on EZ Backup, contact:

                    EZ-Soft Pty. Ltd.
                    G.P.O. Box 880
                    Sydney, N.S.W., 2001
                    Australia
                    Telephone:  011.61.2.365.1271
                    AppleLink:  AUST0367

The EZ Backup file format is copyrighted (C) 1990 by EZ-Soft Pty. Ltd. and is 
printed here with permission.


Definitions

The following definition is used in this document in addition to those defined 
for all Apple II file types:

Date/Time    An eight-byte date/time record as used by GS/OS and the 
             Miscellaneous Tools.


The File Format

EZ Backup savesets are divided into three major segments:  the header, the 
file list and the data.

The Header

The header contains information relating to the saveset as a whole.  It is a 
fixed length of 1,024 ($400) bytes and is defined as follows:

              backupDateTime (+000) Date/Time
                                             The date and time on 
                                             which the backup took place.
              fileCount  (+008)  Word        The number of files stored in 
                                             the saveset.
              rootDirectory (+010) 512 Bytes
                                             A GS/OS input string containing 
                                             the full pathname of the 
                                             top-level directory of the 
                                             saveset.  Note that normally 
                                             this is the volume name of the 
                                             volume that was backed up.
              fileList   (+522)  Long        A pointer used at run-time to 
                                             point to the first entry of 
                                             the file list.  This field 
                                             need not be zeroed when writing 
                                             to disk.
              majRelease (+526)  Word        The major release component of 
                                             the version number of EZ Backup 
                                             used to create the saveset, as 
                                             a two-byte integer.
              minRelease (+528)  Word        The minor release component of 
                                             the version number of EZ Backup 
                                             used to create the saveset, as 
                                             a two-byte integer.
              fileSysID  (+530)  Word        The file system ID of the 
                                             volume that was backed up.
              backupType (+532)  Boolean Word
                                             A flag that indicates whether 
                                             the backup was a full backup or 
                                             an incremental (changes only) 
                                             backup.  A value of TRUE means 
                                             the backup is incremental.
              selected   (+534)  Boolean Word
                                             A run-time flag used to 
                                             indicate that all files in the 
                                             directory tree are selected.  
                                             A value of TRUE indicates that 
                                             all files are selected.
              devIcon    (+536)  Long        A number indicating which icon 
                                             to display for the root level 
                                             when restoring.  This is 
                                             supplied in case the 
                                             configuration of the machine 
                                             doing the restore differs from 
                                             that of the machine that made 
                                             the backup.  Following are the 
                                             icon numbers and device types 
                                             they represent:

                                             File Server  $FFF5
                                             CD-ROM       $FFF8
                                             5.25" Drive  $FFF9
                                             RAM Disk     $FFFA
                                             3.5" Disk    $FFFB
                                             5.25" Disk   $FFFC
                                             Hard Disk    $FFFD

              fileListLen (+540) Long        The length in bytes of the 
                                             file list (defined later).
              totalDisks (+544)  Long        The number of disks required 
                                             by the saveset (excluding the 
                                             disk containing the file list).  
                                             Note that this is not relevant 
                                             to a file-based backup since a 
                                             saveset file cannot be larger 
                                             than the disk on which it 
                                             resides.
              reserved   (+548)  Word        Reserved for future use.
              backupLen  (+550)  Long        The total size in bytes of the 
                                             backup, including the header, 
                                             the file list and the data.
              reserved   (+554)  470 Bytes   Reserved for future use.

The File List

The file list contains a variable number of 128-byte records, the number of 
which is given by the fileCount field in the header.  Each file list entry is 
defined as follows:

              nextFile   (+000)  Long        A pointer that is used at run-
                                             time to point to the next file 
                                             in the file list.  Although 
                                             only used a run-time, this 
                                             field is useful in 
                                             reconstructing the directory 
                                             hierarchy when restoring 
                                             savesets.
              fileInfo   (+004)  62 Bytes    A GS/OS GetDirEntry parameter 
                                             block that describes this file.
              dataOffset (+066)  Long        An offset in bytes from the 
                                             beginning of the file that 
                                             points to the location within 
                                             the saveset at which the data 
                                             fork (if any) is stored.  This 
                                             field is zero if there is no 
                                             data fork.
              resOffset  (+070)  Long        An offset in bytes from the 
                                             beginning of the file that 
                                             points to the location within 
                                             the saveset at which the 
                                             resource fork (if any) is 
                                             stored.  This field is zero if 
                                             there is no resource fork.
              optionListOffset (+074) Long   An offset in bytes from the 
                                             beginning of the file that 
                                             points to the location within 
                                             the saveset at which the GS/OS 
                                             option_list (if any) was 
                                             stored.  This field is zero if 
                                             there is no option_list.  
                                             Note that EZ Backup does not 
                                             currently store the option_list 
                                             for any ProDOS files.
              optionListLen (+078) Word      The length in bytes of the 
                                             option_list (if any).
              parentFile (+080)  Long        A pointer that contains the 
                                             run-time address of the file 
                                             list record of the directory 
                                             that is a parent to the file 
                                             described by this record.  
                                             Although only used a run-time, 
                                             this field is useful in 
                                             reconstructing the directory 
                                             hierarchy when restoring 
                                             savesets.
              currentDir (+084)  Long        If the file described by this 
                                             record is a directory, this 
                                             field is a pointer to itself.  
                                             This is supplied primarily for 
                                             the restore operation so that 
                                             the directory hierarchy may 
                                             be rebuilt.
              selected   (+088)  Word        Used at run-time to indicate a 
                                             file record selection mode.  
                                             If this field is zero, then 
                                             some error occurred during the 
                                             backup that prevented the file 
                                             from being backed up.  A 
                                             non-zero value indicates that 
                                             the file was correctly included 
                                             in the saveset; only attempt to 
                                             restore files that have a 
                                             non-zero selection mode.
              created    (+090)  Boolean Word
                                             A flag used at restore time to 
                                             indicate whether the file was 
                                             created successfully.  A value 
                                             of TRUE means yes while FALSE 
                                             means no.
              fileName   (+092)  36 Bytes    A GS/OS output string 
                                             containing the name of the file.

The Data

The data component of the file contains the contents of all of the files 
described in the file list in a contiguous stream of bytes.  Each file begins 
at a 512-byte boundary.  Each file list record takes 128 bytes, and any 
remaining bytes in the last 512-byte block of the file list are unused.  
Similarly, all stored data forks, resource forks, and option_lists start on 
512-byte boundaries, and any remaining bytes in their last 512-byte blocks are 
unused.


Further Reference
_____________________________________________________________________________
  o  GS/OS Reference
