1. Directory
  2. Apple II Textfiles
  3. resurrect.txt
  by Harold D. Portnoy
  Copyright 1990
      When an AppleWorks word processor or data base file goes bad is not the
 time to worry about how you are going to repair the damage.
      CHANGE-A-FILE (CHGFIL.BXY) is a batch file utility that reads AppleWorks
 Word Processor (AWP) and text (TXT) files; converts AWP files to TXT files, TXT
 files to AWP files, and AWP 3.0 files to AWP 2.x files; and rapidly repairs
 damaged AWP and ADB (data base) files.
      While CHANGE-A-FILE can readily restore damaged AppleWorks word processor
 (AWP) and data base (ADB) files, it cannot restore a file on a disk with a
 damaged directory. RESURRECTION can restore these files .... most often
 rapidly, but occasionally with a little work. The disk blocks containing the
 file that cannot be accessed are still on the disk. The problem is where are
 the blocks and how can they be placed in an accessible file. RESURRECTION
 answers these two questions. RESURRECTION is not a substit ute for Change-A-
 File (see note below). RESURRECTION                                        -  -
 Source/Destination Selection 
      Insert the damaged disk (source) into a disk drive and then enter the slot
 and disk number or accept the default values. The complete file name, including
 the prefix, of the file to be created (destination) from the damaged file is
 then entered. The destination file cannot be on the disk in the source
 slot/drive. This prevents the new file from being on a damaged disk. Next the
 filetype is selected (TXT, AWP, or ADB).      The destination file does not
 have to be completed in one session. To append to a partially completed file,
 enter the destination file name. At 'File already exists. Replace? (N/Y)',
 enter 'N'. At 'Append ? (N/Y)', enter 'Y'. New blocks will then be added to the
 end of the previous file.
 Function Selection 
      The function screen is divided into an upper and lower half. The file name
 is printed in the left upper corner and the total blocks on the source disk in
 the right upper corner. The number of blocks on the disk is initially
 determined from the volume directory on block 2. If block 2 is damaged, then an
 attempt is made to determine volume size by two other methods. If all methods
 fail, then a 'VOLUME BLOCKS $' window will open. Enter the volume size in
 blocks. This should be rarely necessary. The follow ing can be used to
 determine the number of blocks. A 5.25 inch disk has $118 blocks (140 blocks);
 a 3.5 inch disk, $640 (1600 blocks); and hard discs, $800 * size in megabytes.
 The functions are printed on the bottom line of the screen. The following can
 be selected: Arrows, Quit, Read, Write, Dump, Scan.
      Read: Blocks from the damaged disks are accessed either by the up and down
 arrows, which select the blocks sequentially, or by entering 'R'. A window
 appears with 'Read Block $'. Enter the desired block number. The block is
 displayed in the lower half of the screen. The block number is displayed in the
 left margin at 'Read Block'. For ease of review, only the characters in the
 range of $20 - $7F (the text characters) are printed to the screen. All other
 characters are replaced with a period.
      Write: Enter 'W' to write the block to the new file. The block is
 displayed on the upper half of the screen. Only a previously read block can be
 written to file. The block number is displayed in the left margin at 'Write
 Block'.      The next block in the file can be accessed by the arrows or 'R'
 and the process repeated until all the blocks in the old file are transferred
 to the destination file. Once a block in the source file is found, succeeding
 blocks are frequently found in sequential order and easily accessed by the up
      Dump: Any block that has been read can be dumped to the printer by
 entering 'D'. The easiest way to reconstruct a file is to first dump all the
 blocks, which are identified with a block number,  to a printer. Determine the
 order of the blocks. Reenter the program and write the blocks to the
 destination file in the proper order.      The printer output is set to slot 1.
 If you use a different slot, then change the low nibble of byte $03 (C1) to the
 slot number. This is most easily accomplished using a block editing utility
 such as ProSel Block Warden. Alternately the following patch will suffice after
 setting the prefix to the directory containing RESURRECTION.
           POKE 768,19n  (where n = slot number + 2) 
      Scan: Scan allows bad blocks to be easily identified. Selecting 'S' brings
 up the 'SCAN BLOCK $' window. Enter the block number from which the scan should
 start. The bad block numbers will then be printed in hex. The scan can be
 interrupted by pressing any key. The block numbers can also be sent to a
      Auto-Restore: There are two Auto-Restore functions: by file name and by
 index block. Auto-Restore by file name is the best method to restore a file. It
 requires, however, that a parent directory be intact. Auto-Restore by index
 block only requires that the index block of the file be intact. It is less
 efficient than restoring by file name and should be used only after Auto-
 Restore by file name has failed. It is much more efficient than reconstructing
 a file using the Read/Write functions. Entering 'A' brings up a menu for
 selecting either Auto-Restore by file name or by index block.
      Auto-Restore by file will restore a file as long as the parent directory
 or subdirectory and the index block(s) of the file are intact. If the volume
 directory is damaged or any of the other directories up to, but not including,
 the parent subdirectory, the file can still be recovered. A common cause for
 failure to access a file is damage to the volume directory in block 2. If the
 directory file entry of the file is not in block 2, the file can be recovered.
 On selecting by file name, the 'Find File' window is opened. Enter the file
 name only. Do NOT enter any prefix. The file type must be the same as
 previously selected. Auto-Restore will search the damaged disk for the file.
 Pressing any key will abort the search. If the file is found, identifying
 attributes are displayed in a window. The attributes are parent directory or
 subdirectory, file type, size in blocks, and modification date and time. If
 this is the correct file enter 'Y' at 'Accept (N/Y)'. If not, you will be given
 the option of continuing the search or aborting. 
      When the file is accepted, Auto-Restore automatically reconstructs the
 damaged file under the destination file name. DO NOT INTERRUPT the
 reconstruction. When complete the program returns to the input menu.
      Auto-Restore by index block requires that there be at least two blocks in
 the file and cannot directly handle files in excess of 256 blocks. It is ideal
 for sapling files, that is, files of 2 - 256 blocks. Most files fall into this
 category. It cannot detect seedling files (1 block). Tree files ( > 256 blocks)
 must be reconstructed from file segments of 256 blocks. The algorithm used to
 detect an index block may not detect all index blocks and may recognize a non-
 index block as an index block (pseudo- index block). The former is more
 important in that a desired file cannot be detected. 
      Selecting Auto-Restore by index block presents a new function screen:
 Select Arrows (up and down), Accept and Next index block; and an 'Index Block
 $' window. Enter '0' in the window, when searching for a file for the first
 time. If you have an idea of approximately where the file is on the disk, then
 enter a block number that is known to be before the index block of the file.
 Select 'N'. The disk will be searched for an index block. When found, the first
 two blocks of the file will be displayed on the  screen. If you need more
 information in order to decide if you have the correct file then select the up
 arrow and two more blocks will be presented until the file ends. Selecting the
 down arrow, backs up two blocks. 
      When you are satisfied that the correct file has been found, select 'A'
 and the file will be reconstructed. In the search, errors such as 'Bad Block'
 and 'Block Range Error' may be encountered. The former indicates a bad block
 has been encountered. The latter indicates that the algorithm found a pseudo-
 index block and a file block number was tried that exceeded the volume size.
 Continue by selecting 'N' for the next index block. 
      With a little time and effort, tree files can be first reconstructed into
 multiple files of 256 blocks. AppleWorks can then be used to append one file to
 the next in order to reconstruct the original tree file. Not the best, but
 better than block by block.
      Quit: Enter 'Q' to complete the destination file.
      ESC: Entering ESC at any point in the program resets to the initial
 screen. At the initial 'Slot' request, ESC quits the program. The destination
 file is not saved.
 NOTE      The text files can be read with any appropriate utility such as
 'View' in Change-A-File. AWP and ADB files must first be processed by Change-A-
 File's 'AWP File Doctor' or 'Restore ADB' in order to be accessed by
 Icons      CF.RES.ICONS contains Change-A-File and Resurrection icons. The
 Change-A-File icon is courtesy of Karl Bunker. To use these icons in the
 Finder, place CF.RES.ICONS in the ICONS subdirectory of the boot volume
 (BOOT.VOLUME/ICONS/CF.RES.ICONS) and reboot.  The two programs must have file
      Auto-Restore is not accessible unless you have the CHANGE-A-FILE password.
 If RESURRECTION is placed in the same directory as CF.SYSTEM, the Auto-Restore
 function will be unlocked on entering the password and then quitting
      Transfer the CHANGE.FILE and RESURRECTION files to the volume directory of
 a disk under ProDOS (P8). Rename CHANGE.FILE to CF.SYSTEM. Be sure this file is
 the first .SYSTEM file in the directory (e.g. ahead of BASIC.SYSTEM). Boot the
 disk. (You must boot directly into CF.SYSTEM.) The password screen will be
 presented. Enter the password. When the menu is presented, select Quit. The
 CHANGE.FILE will be rewritten to the disk without the screen. The Auto-Restore
 function of RESURRECTION will be activated.  Rename CF.SYSTEM to CHANGE.FILE or
 any other name of your choice. Whether you have the password or not, the
 password screen will be removed. If you enter the password, all the utilities
 will be able to be used in both programs. If not, only the 'free' utilities
 will be able to be used. 
      The CHANGE-A-FILE password can be obtained for $10.00 from: 
           c/o Harold D. Portnoy 
           1431 Woodward 
           Bloomfield Hills, MI 48013
 All rights reserved.
 AppleWorks, copyright Claris Corporation ProSel, copyright Glen Bredon
      Suggestions, bugs and other trivia to:
         Harold D. Portnoy
         Compuserve [75156,2436]         GEnie [H.PORTNOY]
      1.0- First attempt.      1.1- Improved layout and docs. Adds scan.
 1.2- Adds Auto-Restore.      1.3- Improved Auto-Restore. Also removes bug.
 1.4- A few bug fixes and minor improvements.      1.5- Improved determination
 of volume size and a bug           fix.      1.6- Adds Auto-Restore by Index
 Block.      1.7- Improved algorithm for Auto-Restore 

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