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                         | THE JAM PACKER V4.0 |

                         Release Date:  17.06.1991

     The   JAM  Packer  is  an  executable/datafile  and  whole   disk 
compression  program.   A full GEM user interface provides  convenient 
and user-friendly operation.


     Four  compression  methods  are  implemented.

LZH -     This  is a modified version of the method used in the  first 
          Lharc  series.    LZH  provides  reasonably  fast  and  very 
          efficient  compression,   though  it  does  take  longer  to 
          uncompress  than  any  other method  available  in  the  JAM 

LZW -     This   method   provides  fast  and   reasonably   efficient 
          compression.  It has the fastest decompression speed.  It is 
          ideally  suited for when fast de-compression speed  is  more 
          important than smaller compressed file size (eg.  on a  hard 

V2 -      Compresses  very slowly,  but de-compression speed  is  much 
          better  than LZH.   It can also compress files smaller  than 
          LZW,  but not quite as good as LZH.   Since the introduction 
          of  the  ICE  pack  method  into  the  JAM  packer,   V2  is 
          essentially  redundant.   In  a future upgrade  it  will  be 
          removed and replaced by something much better.

ICE -     This  method is used in the Pack-Ice packer and is based  on 
          V2,  though it slightly improves on V2 in both time taken to 
          compress,  time  taken  to de-compress and  compressed  file 


     Two  types  of  files can be packed.   "Data"  files  are  simply 
     compressed.   "Program"  files are compressed and  the  necessary 
     code to de-compress and run them is included in the file.

     If a Program file is packed,  then you can choose whether or  not 
     the  screen  will "Flash" when unpacking and whether or  not  the 
     "Heading" will appear when the file unpacks.

NOTE:  Packing resource,  data,  dictionary, help or any other support 
       files  for a program will cause that program to fail.   If  you 
       think about it, this obviously cannot work as the program using 
       these  files has no idea they're packed or how to unpack  them!  

       Also  note  that  program  files may  not  decompress  and  run 
       properly from some shells (notably the Laser C shell).

     Holding down the ALTERNATE key during a pack will cause it to  be 
     aborted.   You are not given the option of resuming, so make sure 
     that when you hold down ALTERNATE, you really do want to stop the 
     current pack.

     This  option also works when in the "Disk  Packer",  though  only 
     when  data is being packed,  not when reading or writing  to  the 

     This  option  has been updated significantly since V3.0  and  now 
     works properly.

     The  "Disk  Packer"  reads in a whole disk and packs  it  into  a 
     single file.  This is useful for transmission of entire disks via 
     modem and archival purposes among other things.   You can  choose 
     either of the four pack methods to be used during the disk  pack, 
     or  alternatively  you can choose no compression from  the  "Disk 
     Packer" box.

     If the "use boot" box is selected, the format of the disk is read 
     from the boot sector.  Only use this option if you are absolutely 
     sure that the disk has a valid boot sector, otherwise the results 
     will be unpredictable.

     If the "use boot" option is not selected, the JAM packer attempts 
     to  determine  the format of the disk by  itself.   There  is  no 
     guarantee  that it will get it right,  though if any  mistake  is 
     made, it will be to pack too much data, rather than not enough.

     If this option is selected,  it is only active if the "use  boot" 
     box  is  selected.   It  ensures that  data  clusters  which  are 
     allocated  by the FAT (File Allocation Table) are the  only  data 
     packed.  This is useful if you have deleted files from a disk, as 
     although  deleted,  the  data  will  remain  on  the  disk  until 
     over-written by another file.

     This is used during a disk unpack only.   If the "format" box  is 
     highlighted, the disk will be formatted to the appropriate format 
     before data is written to it.

     Note:  11  sector format is not supported,  so if you  have  disk 
     packed  an 11 sector a track disk,  make sure you have  formatted 
     the  destination disk 11 sectors a track with a program  such  as 
     Fastcopy III.

     Select  this option when you want a fast conversion of  a  floppy 
     disk into a file.  No compression is used, the data from the disk 
     is just copied into a file.

     The  "Multi-Packer"  is a handy feature when a  large  number  of 
     files need to be packed.   Wildcards are supported.   Choose your 
     source  directory and type in the file name template to be  used.  
     Eg.  "*.*" will pack all programs in the selected directory;
          "*.DAT" will pack all programs with a ".DAT" extension.

     If the "Program" button is selected then files with the  extender 
     ".TOS",  ".TTP",  ".PRG"  or  ".APP" will be packed  as  programs 
     (executables  which  will uncompress and run),  as if  they  were 
     selected  individually  from  the normal pack  box  as  "Program" 
     files.   Otherwise, they will be packed as data files, which will 
     not automatically uncompress and run.

     The packed files overwrite the original files.


JAMPACK4.PRG   - The JAM packer program.
JAMPACK4.DOC   - What you are reading now.
DEPV2.S        - Assembly depack source code for V2.
DEPICE.S       - Assembly depack source code for ICE.
DEPLZW.S       - Assembly depack source code for LZW.
DEPLZH.S       - Assembly depack source code for LZH.
LDRUNLZH.S     - Trap #1 file load/depacker.


We take no responsibilty for any damage which may arise from the  use 
or misuse of this program.


You  may  make  copies and distribute this program,  as  long  as  the 
program  and  documentation file remain unchanged,  and no  profit  is 

This  program is shareware.   If you find it useful,  please  send  us 
something,  be it money or words of encouragement,  it doesn't matter.  
Bug reports and suggestions for improvement are also welcome.

Write to us at either of the following addresses.

     +-----------------+          +-----------------------+
     | Andrew Knipe    |          | Tim Knipe             |
     | P.O. Box 369    |          | RSD Maiden Gully Road |
     | 367 Collins St. |          | Bendigo, 3551         |
     | Melbourne, 3000 |          | Victoria              |
     | AUSTRALIA       |          | AUSTRALIA             |
     +-----------------+          +-----------------------+

                            .. * 
                            .   . 
                             *  .
                            .  . 

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