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/\______ ___/\_____ ________ __ /\ __ / ___/ ¬/ ¬// \__¬\ \_____ ¬\/ ¬\/ \| | \__ ¬\ /\__/ ¬| \_ / _/ | \_ / | | ¬| \ ¬ | // \ \ | / | ____/__ _ _____/ \__\ \______/\__ .::::::::::\__/\|::PRESENTS::\__/::::::::::. Typed and edited by DIT FOR FIREFLASH-SkIdRoW 20-12-1993 DISK EXPANDER V2.1 By SCHATZTRUHE TABLE OF CONTENTS 1. INTRODUCTION PAGE 1.1 About the program 2 1.2 Remarks 3 1.3 Functional overview 3 2. INSTALLATION 2.1 What to do before installation 3 2.2 Installing the program 4 2.2.1 Commodore`s installer 4 2.2.2 Installation on a hard disk 5 2.2.3 Installation on a floppy disk 6 1.3 Copy protection 6 3. USING DISKEXPANDER 3.1 Basic concepts 7 3.2 Starting DiskExpander from the WorkBench 11 3.3 Starting DiskExpander from the Shell 15 3.4 Inserting DiskExpander into the Startup-Sequence 15 3.5 Technical background and restrictions 17 4. THE COMPRESSION LIBRARIES 4.1 Basic concepts 18 4.2 The EPU0 - library 19 4.3 The EPU1 - library 19 4.4 The NUKE - library 20 4.5 The BLZW - library 20 4.6 The FAST - library 21 4.7 Additional libraries 22 5. THE UTILITY PROGRAMS 5.1 Device Packer 22 5.2 DEStatistics 25 6. MISCELLANEOUS 6.1 Hints for using the program 26 6.2 Special note to Kickstart 1.2/1.3 owners 28 6.3 Future enhancements 28 6.4 Registration 29 PAGE 1 1. INTRODUCTION 1.1 About the program Are you in need of more hard disk space? Have you been envying those high capacity hard disk drives available for IBM and highend Amiga's? Until now, the only solution has been a new, bigger hard disk or a special HD drive, both being rather expensive add ons for your computer. But now there is DiskExpander, a cheap alternative to the expensive ones mentioned before. DiskExpander can double the current capacity of your hard disk without the addition of any special hardware, consisting only of a software package. The secret behind this phenomenon is data compression. Any data that is written to disk undergoes a compression to 30% - 70% of its original size. When this data is needed again, DiskExpander decompresses it and puts it to its original form and size. All this happens automatically, hidden behind the multitasking system. Apart from a slight increase in access time, you will not notice any difference when using the programs and data. The reduction of disk space needed for a file is done by a number of highly optimized compression algorithms. These algorithms have been used on a lot of different computers for a long time and they have been proven to be reliable. To adjust DiskExpander to your personal needs, you may select whether compression shall be fast or efficient. Fast compression does not maximize data compression, while efficient compression takes more time. There are, of course, alternatives between these extremes. The compression algorithms are delivered in form of libraries. Recently, a version of these libraries called XKP has appeared to become the standard. These libraries have proven to be highly reliable and are being continuously being improved. A lot of XPK libraries are available on public domain disks, such as the Fred Fish series. DiskExpander supports this standard by using XPK libraries for packing and unpacking data. Some XKP libraries come along with DiskExpander, while a lot more can be installed from public domain disks. In addition, other common library formats are supported. This is explained in later chapters of this manual. DiskExpander and its utility programs have a workbench like graphical user interface which makes the program easy to use, even for people not so familiar with computers. All you have to do is tell DiskExpander which floppy or hard disk drive to compress. Anything else is done automatically. For advanced users there is a large number of parameters that can be changed to increase DiskExpander`s efficiency. The utility programs help you to easily compress already existing programs and data. Even whole hard disk full of files can be compressed, which provides you with a lot of free space. The program works well along with all devices of AmigaDOS. It is not limited to floppy disk or hard disks. Even normal floppy disks will have a capacity of about 1.5 MByte when compressed with DiskExpander. Now, a whole Workbench including fonts and printer drivers can be stored on just one disk. PAGE 2 The program cannot be started from the delivered disk. It has to be installed, even if used on floppy disks only, to adjust the software to the existing hardware. Most of the installation process is done automatically using Commodore`s Installer. The installation process is described in Chapter 2. BEFORE USING DISKEXPANDER FOR COMPRESSION OF FLOPPY OR HARD DISKS, PLEASE READ THIS MANUAL CAREFULLY. This helps you avoid problems (e.g. loss of data) that might occur when the program is used in the wrong way. 1.2 REMARKS On the program disk you will find a file called "Read.me!". Since the program is being constantly updated, this file contains information that was not available when this manual was printed. Please use it as an addendum to your manual. By clicking over the corresponding icon on the disk, the text is displayed on screen. You may also load the file into your favourite word processor or print it. 1.3 FUNCTIONAL OVERVIEW DiskExpander is a software package consisting of three programs. The most important one is of course, the program "DiskExpander" itself. This program is used to select the DEVICES to be compressed. It also serves to setup the COMPRESSION LIBRARY and a number of other parameters. A detailed description of this program is found in Chapter 3 of this manual. The program "DevicePacker" preforms another important task. It compresses existing files, directories and even whole devices. This becomes necessary when there are already programs and data on the hard disk or floppy before DiskExpander is first used. DevicePacker helps you to compress these files. Finally, the utility program "DEStatistics" calculates the pack-rate achieved with DiskExpander. The program can return a statistics of a single file or a whole device, depending on what your imports are. The results can be displayed as text or graphically. The two utility programs DevicePacker and DEStatistics are explained in Chapter 5. In addition to these three programs mentioned above, the disk contains a lot of other files necessary for a correct use of DiskExpander (e.g. XPK - libraries and Commodore`s Installer). 2. INSTALLATION 2.1 What To Do Before The Installation DiskExpander cannot be run from the distribution disk as this contains an uninitialized version of the program. Before you can use the program, it has to be installed, even if you PAGE 3 want to use it with floppy disks only. For this purpose, the install program allows you to copy the program to a Workbench disk. If you want to do this, please make a backup copy of your Workbench disk before you start the installation. In order to install DiskExpander you have to rename the duplicate to "WorkbenchDE". This copy is used during the installation process. You should not use your original Workbench disk, because DiskExpander compresses the contents of the disk to save space that is needed for the DiskExpander files. Due to this compression, the Workbench disk will contain more free space after installation than it did before. IF YOU WANT TO USE DISKEXPANDER ON A HARD DISK, IT`S A GOOD IDEA TO MAKE A BACKUP OF ALL THE PROGRAMS AND DATA ON THE HARD DISK BEFORE THE INSTALLATION. The software market offers a lot of different programs for this purpose, but you may also use the program "HDBackup" which is included on the Workbench 2.0 disks. Please read the Amiga documentation for information about this program. You should also make regular backups of your hard disk after DiskExpander has been installed. Since a hard disk contains an enormous number of files, the loss of data due to a hardware or software failure can be serious and quite annoying. Hard disks are sensitive electronic products and can be easily be damaged. A regular backup keeps the consequences of such damage to a minimum. 2.2 Installing The Program 2.2.1 Commodore`s Installer The DiskExpander software package is installed using Commodore`s Installer. Start the installation process with a double-click over the icon "INSTALLHD" for installation on a hard disk or over the icon "INSTALLDISK" for installation on a floppy disk. If you close the installation to take place on a floppy disk, please use the backup copy of your Workbench disk mentioned earlier. After the chosen program is loaded, a window with the welcome message appears on screen. Below this message you will find an area which serves to select one of the three different installation modes. NOVICE USER This setting is not used during the installation of DiskExpander and is therefore not an option. INTERMEDIATE USER This setting allows you to influence some aspects of the installation process. You may select the select the target path to which the program is installed. Any other task is performed automatically by the Installer. EXPERT USER This setting allows you to change some program parameters during the installation. You may specify which compression/decompression libraries should be installed with DiskExpander. PAGE 4 You may also choose between Kickstart 1.3 colours and those of the new OS 2.x. The rest of the installation is similar to the selection "Intermediate User". The lower portion of the window contains four gadgets. The upper left one "PROCEED WITH INSTALL" starts the installation process while the upper one "ABORT INSTALL" aborts it. The two gadgets below are of little importance. The "ABOUT .." gadget displays information about the install program itself and the "HELP .." gadgets calls the online help function. Please select the desired mode of installation and then click over the gadget "PROCEED WITH INSTALL" to start. Another window is displayed. Please click again over the "PROCEED" gadget without changing any parameters in that window. Please note that the DiskExpander original disk must not be write protected during installation. 2.2.2. INSTALLATION ON A HARD DISK The installation of DiskExpander on a hard disk requires that you have booted your system from the hard disk, before the installation process. The logical directories LIBS:, L:, and C: must be assigned correctly, which normally happens automatically when booting from a hard disk. If you have not already done this, please start the installation program by double clicking over the "INSTALLHD" icon. After the two welcome windows mentioned in the above paragraph, you are asked to enter your name and address. These data will be stored on the original program disk. Please enter your personal data correctly. This, together with returning the registration card, allows you to buy updates to future versions of the program containing additional features. Incorrect or incomplete entries are not acceptable. After entering your personal data, you can choose the directory in which DiskExpander and its utility programs shall be stored on the hard disk. You may, of course, create a new directory especially for that purpose using the Installer. The output directory "DISKEXPANDER" will be created automatically. Inputs like "WORK:" or "HD!:TOOLS" for superior drawers to the "DISKEXPANDER" one are sufficient. But that all subdirectories superior to "DISKEXPANDER" must exit before installation (e.g. "TOOLS" on HD1:). The program is then installed to "HD!:TOOLS/DISKEXPANDER". Having chosen the path, you may select any number of compression/decompression libraries to be installed with the program. This selection is only available to those who have chosen the "Expert User" installation mode. Otherwise, all the libraries will be installed automatically, which is recommended since the libraries do not use a lot of disk space. If you are an "Expert User" you may also choose whether the program icons shall be displayed in Workbench 1.3 or 2.x style. The install mode "Intermediate User" chooses the icons that match your current operating system version. PAGE 5 After entering these parameters, the DiskExpander files will be copied to the chosen directory. If no error occurs during this copying process, the program will be in an executable state afterwards, and you may use it to compress files on your hard disk and floppy disks. This is explained in Chapter 4 of this manual. 2.2.3. INSTALLATION ON A FLOPPY DISK The installation on a floppy disk is also handled by Commodore's Installer. Please remember to use a backup of your Workbench disk for installation. This copied disk must be named "WORKBENCHDE" for the process to work properly. If you do not know how to rename a disk please consult your AmigaDOS manual for the details. When you have copied and renamed the disk, start the installation with a double-click on the "INSTALLDISK" icon. After the two welcome windows mentioned in paragraph 2.1.1, you are asked to enter your name and address. These data will be stored on the original program disk. If you have chosen the option "EXPERT USER", you will now be able to set some program parameters. First you may select the compression libraries to be installed. Then you are asked whether you prefer the program icons to be displayed in Workbench 1.3 or 2.x style. The option "INTERMEDIATE USER" will not allow you to make these decisions. DiskExpander will be installed with all libraries and the icons that match your current operating system version. You are now asked to insert the copy of Workbench disk into a drive. The installation program will compress existing files on this disk to create space necessary for DiskExpander and its data files. Afterwards, the different programs belonging to the DiskExpander software package are copied to the disk, and the Startup-Sequence is modified. The installation is finished. You will now have an executable version of DiskExpander on the copy of Workbench disk. When booting the system using this workbench copy, DiskExpander will be started and preform its packing job. Please read Chapter 4 of this manual for further information. 2.3 COPY PROTECTION Yes, the program DiskExpander does contain a copy protection. This copy- protection has been installed on demand of JAROSLAV MACHACEK, who developed the software. It took Jaroslav Machacek a lot of time and hard work to program DiskExpander, and he wants to protect his work from unauthorized copying this way. Fortunately, DiskExpander`s copy protection is a new and quite INTELLIGENT one, Which does not hinder the honest program owner from working with the software. You simply have to enter your name and address when the program is installed, as explained above. During the daily use of DiskExpander, the copy protection will be transparent to the user. PAGE 6 Any major changes in DiskExpander`s configuration can make it necessary to use the original disk again. In this case, simply insert the original disk into the internal drive DF):, even when the drive`s LED is lit continuously. The program will continue to work then. It will be possible to use DiskExpander if you cannot find your original disk at the moment or if you click the gadget "Cancel" by mistake. Already compressed files will still be decompressed, but DiskExpander will not compress files anymore. However, during the next boot process, the original disk will be required. During disk use a requester may occur which asks you to insert the original program disk. Afterwards you are requested to insert your workbench copy again. In this case, remove the write protection of the WB disk shortly to avoid the insertion of the original disk every time you re-boot your system. If you want to compress a whole diskette with the "DEVICEPACKER" there may not be enough storage space left even for the condensed data. A 100 percent full" diskette can not be packed with the "DEVICEPACKER". The maximum use for a diskette before packing is limited to 98 percent. Please note that the original program disk cannot be copied using the Workbench`s copy function, because some sectors on the disk are protected. To get a backup copy of your original disk, use the program DEBACKUP found on the original disk. This program uses Commodore`s Installer to copy all files from the original disk to a fresh formatted and empty disk, which must be named "DEBACKUP". This disk might become useful in case your original disk becomes unreadable due to physical damage. It will allow you to use DiskExpander for decompression of existing files. Registered program owners may order a new original disk. This requires returning the defective disk and the small fee of $5 to the Schatztruhe Gmbh. We will ship out the replacement within 3 days after receipt. 3. USING DISKEXPANDER 3.1. BASIC CONCEPTS After the successful installation, the different programs of the software package may be used. The main program called DiskExpander is found in the newly created directory of your choice on the hard disk or the floppy disk, depending on where you you installed the software. Use this program to select the drives to be compressed during future use. There are also some adjustable parameters which will be explained in the following paragraphs. DiskExpander can be run from the Workbench as well as from the Shell. In either case the same parameters will be required, through the input of these parameters will work different. Therefore the parameters will be explained with no regard to a specific input method (Workbench, Shell). Paragraphs 3.2 and 3.3 deal with the characteristics of a start from either Workbench or Shell. The different parameters available for configuring DiskExpander can be grouped into three categories. The first group contains parameters which are indispensable for the program to PAGE 7 work correctly. The devices to be compressed belong to this group, as well as the compression library to be used. The second group of parameters contains commands that DiskExpander shall execute on the specified device, such as installation or removal of compression routines to or from AmigaDOS. The third group provides a number of parameters which adjust DiskExpander to your personal needs. You may select whether data to be stored on a device should always be compressed, and whether the directory command reports the compressed file size or the original (decompressed) size. Since the parameters belonging to the first group are more important than the other ones, they will be explained first. DEVICE The most important parameter is the selection of the device (floppy disk, hard disk ..) DiskExpander shall work on. Compression routines can be installed to and removed from this device at will. Any device similar to a floppy disk or a hard disk will work with DiskExpander. A more detailed specification is given in Chapter 3.5 "TECHNICAL BACKGROUND". When you have started DiskExpander using the graphical user interface, the device may be chosen from a list of all available devices. LIBRARY This is another very important parameter . It is used to select the library that is used for compression and decompression on the selected device. Along with DiskExpander comes a number of these libraries suitable for different purposes. A list of advantages and disadvantages of those libraries is given in Chapter 4. Please note that the names of the libraries especially developed for DiskExpander (epu0 and epu1) must be written in lower case, whereas the names of the XPK libraries must be written in capitals. Here, too, the program allows you to select one library from a list of available ones using the mouse if the program uses the graphical user interface. If no library is chosen, the XPK library NUKE is used as default. During our testing period, this library achieved the best results, especially in compression speed. BLOCK This parameter determines the amount of memory used during the compression of a file. This memory is permanently used and can range from 2 to 60 KByte. The default is 10. A smaller Block value will use less memory, but compression speed and efficiency will also decrease. If you set Block to 20, exactly 2x20 KByte of RAM will be reserved for opening a file. TABLE This is the maximum file size that DiskExpander can handle in multiples of Block. It`s important for managing the compressed files. Table may vary from 500 to 20000 with a default of 1000. As setting of, for example, Block = 20 and Table = 1000 results in a maximum file size of 20 MByte (20x1000x1000). PAGE 8 The following group of parameters contains the commands DiskExpander can execute: INSTALL This command serves to install compression routines for the specified device into AmigaDOS. Using the default setting will result in compression of any file during a write process and decompression when a file is being read later. REMOVE This command is used to remove a previously installed DiskExpander from a specified device. After this command is executed, no data will be compressed when written to the device. Please note that there will also be no decompression of files already packed, so these files cannot be read correctly without DiskExpander. If there are open files when this command is selected, the execution of the command is delayed until the files are closed. The compression routines will then be removed from AmigaDOS and the used memory will be released. A re-installation of DiskExpander on this device is only possible after this has been done successfully. INFO This command gives you an overview of the current settings of DiskExpander concerning the specified device. It is only available from the Shell. When using the graphical user interface, the setting of all device is shown at startup. MODIFY This command, too, is only available from the Shell. It serves to change settings of a device that has already been installed without having to specify all settings again. All parameters not changed will keep their values. There are also a few commands which allow you to adjust DiskExpander to personal needs. These are in detail: UNPACK This is on by default. Any data from the specified device is decompressed during the loading process. NO PACK Choosing this option prevents decompression of data read from the specified device. Its purpose is to allow copying of compressed data from one device to another without unpacking it. PACK This option is on by default. Any data written to the specified device undergoes a compression before it is stored. NO PACK Choose this option to prevent compression of data written to the specified device. PAGE 9 EXAMINE "Examine" refers to the internal AmigaDOS command which is often abbreviated "Exam". This command calculates, for example, the length of a single file, and is used by the command "list c:dir" and others. Choose this option if you want any command displaying the size of a file to show the size of the decompressed (that means the virtual file size) file instead of the physical size. "Examine" is used by default. It makes determination of the file size a bit slower. NO EXAMINE Choose the option if you want the "Examine" command to return the physical size of the compressed file instead of the decompressed file size. EXNEXT The internal AmigaDOS command "ExNext" is similar to "Examine". It serves to determine the length of files. Unlike "Examine" is used to get the size of a group of files (i.e., all the files in a directory) as displayed by "dir" or "list". If "ExNext" is on, the size of the decompressed files are shown instead of the sizes of the physical disk files. The option on by default. NO EXNEXT Use this command if you want the size of the compressed files to be displayed by commands like "list" or "dir". HMODE This is a default setting. If HMode is on, DiskExpander checks whether the compressed part of a file is being written to disk is already bigger than the original file. In case this happens DiskExpander stops the compression and writes the file as a normal (decompressed) Amiga file. This option serves to prevent a second compression of an already packed file if this file is written again. LMODE If this option is activated, there will be no check as done by "HMode". Any files written to the device is compressed by DiskExpander. More detailed information about DiskExpander, including some restrictions resulting from the technology used that are worth knowing, is given in Chapter 3.5 of this manual, it is strongly recommended to read that chapter, as this may prevent problems. PAGE 10 3.2. STARTING DISKEXPANDER FROM THE WORKBENCH The graphical user interface that appears on screen when DiskExpander is started from the Workbench is the most comfortable way to use the program. In the centre of the Workbench screen a window opens. this is where different parameters may be set and also where commands can be executed. *** See Fig 1 *** In the upper left corner of the window, there are five gadgets with the names "Unpack", Pack", "Exam", "Exnext" and NMode". They belong to the corresponding functions explained in the above paragraph. When there is a little tick next to the gadget, the function is activated. When the tick is missing, the corresponding opposite function is active ("No Unpack", "No Pack", "No Exam", " No ExNext" and "LMode"). Right above the gadgets is a string gadget where you may specify the device for which all the parameters are set. To change this value, simply click over this area and change the text. Do not forget the colon at the end of the device name. Alternatively, you may click over the gadget "Devices" at the lower window border, which will display a list of available devices. *** See Fig 2 *** In addition to the device name, the actual settings will be shown. A tick in the column named "U" means that the "Unpack" option is active for the corresponding device. The other options are treated in the same way. The order of options is the same as in the main window. You may select a device from this list using the mouse. The name of the device will then be shown in the string gadget. The string gadget "Library" is used to choose a compression library for the selected device. Please note that name of the XPK libraries must be typed in capitals and all others (epu0 and PAGE 11 epu1) must be typed in lower case. Again, there is a list of available libraries from which one library can be chosen via the mouse. Simply click the gadget "Library" at the lower window border. *** See Fig 3 *** When this manual was ready for press, the XPK library NUKE produced the best compression results, so we made this library the default one. In the case this should change, the program will eventually use another default library. There are also string gadgets for the parameters "Table" and "Block" which already contain the default values. For additional information, The current status of the selected device is shown in the last row. This is where you can see whether DiskExpander has already been installed on the device, or if it has been deactivated. DiskExpander's essential program functions, namely installation of DiskExpander's compressions routines for the selected device and removal of these routines from the selected device, are activated by the two gadgets !Install" and "Remove". Please note that removing the compression routines from a device take a delay of a few seconds, because DiskExpander checks whether there are any open files or not. If you want to install DiskExpander again on the same device, this is not possible until the delay is over. It is, of course, possible to use the selected device during the wait period. If you want to change some of a device's parameters, you may do this without having to remove DiskExpander from the device via the "Remove" gadget and then installing it again. All changes made to any device parameters are updated when you exit DiskExpander. A further special feature that is available when starting DiskExpander from the Workbench is to communicate with DiskExpander via ToolTypes. ToolTypes are program parameters that can be stored together with a program's icon. They are created using the Workbench function "Information". If you have not any experience in the use of ToolTypes, you should read the corresponding chapters of your Amiga manual first. DiskExpander supports the following Tooltypes: DEVICE This is where you should enter the device, to which the given ToolTypes refer. The correct syntax is: DEVICE=RAD: (this will install DiskExpander to the device named RAD: or remove it from that device). This ToolType is absolutely essential for using DiskExpander with ToolTypes. PAGE 12 LIBRARY This ToolType is used to select a compression library for the selected device. Please use the following syntax: LIBRARY=NUKE (this will use library NUKE with the selected device). Do not forget to type the names of XPK libraries in upper case and the other libraries names in lower case. This is an indispensable ToolType. BLOCK Use this ToolType to set the maximum size of one data block for compression and decompression. The default value is 10, which is equivalent to a size of 10 KByte. TABLE Use this ToolType to set the maximum number of blocks a single file may consist of. This affects the parameter "Table" mentioned above. The default is 1000. PACK Use this ToolType to activate or deactivate data compression on the selected device. Enter PACK=YES to enable compression and PACK=NO to disable it. Default is PACK=YES. UNPACK This ToolType is similar to the last one. Use UNPACK=YES to enable data compression and UNPACK=NO to disable it. Default is UNPACK=YES. EXAM Use EXAM=YES to enable the parameter "Examine" and EXAM=NO to disable it. Default is EXAM=YES EXNEXT Use EXNEXT=YES to enable the parameter "ExNext" and EXNEXT=NO to disable it. Default is EXNET=YES. MODE This ToolType chooses the compression mode. MODE=H selects HMode and MODE=L selects LMode. Default is MODE=H. X This ToolType sets the left border of DiskExpander's window on the Workbench Screen. Please enter X=n, where n is a number. Y This ToolType sets the upper border of DiskExpander's window on the Workbench screen. Please enter X=n, where n is a number. This ToolType, together with the last one, sets the upper left corner of the window. INSTALL This ToolType activates DiskExpander for the selected device. The correct syntax is: INSTALL=YES. In case both parameters, INSTALL and REMOVE should have the value YES, DiskExpander checks whether the selected device has already been installed and will install the device only if it is inactive. PAGE 13 REMOVE This ToolType removes DiskExpander from the selected device. The correct syntax is: REMOVE=YES. In case both parameters, INSTALL and REMOVE should have the value YES, DiskExpander checks whether the selected device has already been installed and will remove the device only if it is active. OPENWINDOW This ToolType determines whether or not the graphical user interface will appear on screen. The commands INSTALL and REMOVE will have no effect unless OPENWINDOW has the value NO. Use the setting OPENWINDOW=YES if you want the graphical user interface to appear on the screen automatically. BORDER If the list contains the ToolType BORDER, the appearance of the gadgets border will change. You may find this option useful when working with older versions of the Amiga operating system (up to Kickstart 1.3). Especially interesting is the possibility to install and remove devices without further communication between DiskExpander and the user, even without opening the user interface, simply via the ToolTypes INSTALL and REMOVE. You might expect to need different versions of DiskExpander on your floppy or hard disk if you want to provide INSTALL and REMOVE icons for any available device, but this is not necessary. All you need is a new "Project" icon for each of devices, in which you enter the ToolType and DiskExpander as the corresponding main program. A suitable icon is found on the program disk in the directory DEicons. Simply copy this file to your floppy or hard disk, create the ToolTypes and rename them. You may, of course, copy the file into the directory WBStartup, if you want automatic installation of DiskExpander after every boot (this requires AmigaOS 2.0 or newer). Please note that in this case DiskExpander will be installed at a point of time far at the end of the boot process, so it is necessary that all commands used before DiskExpander's installation are stored on a decompressed device. In this and similar cases, we recommend to leave the boot device decompressed. The last function not mentioned until now is the ability to automatically install the current values into the Startup-sequence, which ensures that DiskExpander will be run again after booting the computer. As this function is rather complex, we have spent a whole chapter (namely Chapter 3.5) to explain this part of the program. It comes right after the description of the use of DiskExpander from the shell. PAGE 14 3.3 STARTING DISKEXPANDER FROM THE SHELL As an alternative to using DiskExpander from the Workbench, you may start it either from the Shell of from the AmigaDOS CLI. In these cases the program uses the following parameters: DISKEXPANDER DEVICE name [PACK/!PACK] [UNPACK/!UNPACK] [EXAM/!EXAM] [EXNEXT/!EXNEXT] [HMODE//LMODE] [BLOCK size] [TABLE size] [LIBRARY name] [?/WB/INFO/MODIFY/REMOVE] The parameter order is of no importance, though we recommend to use the given order for clarity. The parameter "DEVICE" needs a second parameter "name", which must be the name of a hard disk partition, a floppy disk or a hard disk. The parameters "BLOCK" and "TABLE" need a numerical second parameter called "size". The parameters have been explained several times in this manual, so we refrain from doing this again here. It is important to use the "!" for a negation of the parameters which can be negated, so if you want to switch off the option PACK, you will have to use "!PACK". The command "?" lists all available program parameters. If you use the command "WB", the graphical user interface already explained in Chapter 3.2 will appear on screen even if you run DiskExpander from the shell. 3.4 INSERTING DISKEXPANDER INTO THE STARTUP-SEQUENCE Since the program has to be installed newly after every boot of the computer, it is useful to have this done automatically. An integration of DiskExpander into the Startup-sequence is the most practical way to achieve this, since the Startup-Sequence is, in fact, started after every boot. All you have to do is insert the command for starting DiskExpander in the Startup-Sequence, preferably at the beginning. You may do this using a text editor like AmigaDOS ED. A more convenient way, however, is to use a function we have integrated into the DiskExpander main program exactly for that purpose. This function is called "Modify Startup" and can be reached via the graphical user interface. You may have already noticed the corresponding gadget. Use it to have modifications to the Startup-Sequence done automatically. To achieve more flexibility, we have included several programs options that can be called by a pulldown menu in the graphical user interface. PAGE 15 *** See fig 4 *** The following seven options are available DISPLAYED PARAMETERS .... Use this option to have only those parameters in the Startup-Sequence that refer to the device momentary displayed in the user interface. Parameters are taken directly from the user interface and written to the Startup-Sequence. the selected device does not have to be installed. This option is automatically activated when the program is started. INSTALLED PARAMETERS .... Use this option to add all installed devices to the Startup-Sequence. We recommend to use this kind of installation when there is a large number os installed devices whose parameters have to be added to the Startup- Sequence. REMOVE ALL .... If you choose this option and then click over the "Modify Startup" - gadget, all existing DiskExpander entries will be removed from the Startup-Sequence before any changes are made. Then, the, new entries are added to the Startup-Sequence. In case neither of the first two options is marked with a tick, this option just removes all existing DiskExpander entries from the Startup, without writing new ones. REMOVE SELECTIVE .... When this option is active, DiskExpander removes only those entries from the Startup-Sequence, that will be newly installed. This is the default setting. The next three parameters are used to tell DiskExpander where to insert the entries into the Startup-Sequence: INSERT AFTER MOUNT OR AS FIRST LINE .... This setting can be used for devices that are installed in the Startup- Sequence via the command MOUNT. In this case, the corresponding DiskExpander call must be inserted after the MOUNT command. The option is used for devices installed using MOUNT as well as for devices that do not need "mounting". If there's a MOUNT for the selected device, DiskExpander will insert the entry after the mount. If no MOUNT exists, the entry will be inserted at the beginning of the Startup-Sequence. This is the default setting. INSERT AFTER MOUNT OR NOWHERE .... This option is similar to the one mentioned before. Installation entries will be inserted after the device's MOUNT. If there is no such MOUNT, the device will not be inserted. PAGE 16 INSERT AS 1ST LINE .... The use of this option forces DiskExpander to insert its installation entries at the beginning of the Startup-Sequence. The combination of these options provided any reasonable possibility of an installation DiskExpander into the Startup-Sequence. 3.5. TECHNICAL BACKGROUND AND RESTRICTIONS DiskExpander is basically a program that modifies parts of AmigaDOS to the affect that all data undergoes a compression when being saved and a decompression when restored later. This process is, of course, invisible to the user. DiskExpander has to be started after every boot of the computer. How this can be done automatically was explained in the previous paragraph about adding DiskExpander to the Startup-Sequence. Internally, the program hooks itself to the AmigaDOS and watches data input and output. DiskExpander catches any access to a packed device and uses its compression routines instead of the original AmigaDOS functions. This is, as mentioned before, invisible to the user. Apart from a slight increase in access time due to the compression, the user will not notice any difference. This technique works well along with existing Amiga software, and the amount of memory needed for that purpose is a few KBytes, which is obviously not very much, but this is explained in further detail in Chapter 5. When a compressed file is being written to disk,DiskExpander also stores the name of the compression algorithm and the chosen parameters. In case you change the DiskExpander setup, you will still be able to restore the old files, because DiskExpander knows which compression library and which parameters to use. If you later save or overwrite the file, DiskExpander will use the new library and the new parameters automatically. There are also some restrictions which must be taken into account to guarantee a problem free working of the program. The most important restriction is the one already mentioned: DiskExpander has to be started after every boot of the computer. This is normally an automatic procedure, but will only work if all files loaded before the execution of the Startup-Sequence are stored in an decompressed way, the Startup- Sequence itself and all the files belonging to the DiskExpander software package (DiskExpander, handlers, libraries). If any of these files undergo a compression, the operating system will not be able to execute them correctly during a boot process. However, no data will be lost due to these faults. If this problem occurs, just start DiskExpander manually, switch off the option "Pack" for the boot device, and use the utility program "DevicePacker" to decompress the files. After this procedure, everything should work normally. We describe the method of packing all files except vital ones for booting the computer in Chapter 6 "Miscellaneous". Another possibility especially for hard disk owners is to create a boot partition which contains all necessary data for the setup process in uncompressed form and eventually several data partitions which can be furnished with the DiskExpander at will. PAGE 17 Another restriction refers to the devices that can be compressed. It is only possible to pack devices whose structure is similar to the one of a floppy disk or hard disk. This means the devices must have an input as well as an output. It is not possible to pack a device such as a printer. In technical terms, this means that the devices must support AmigaDOS commands SEEK and LOCK. The condition is fulfilled by floppy disks, hard disks and most ram disks. The RAM: (AmigaOS version 2.0 and higher) and the device PC0: are not yet supported by DiskExpander and thus may not be compressed. During the use of DiskExpander, two additional AmigaDOS errors may occur: ERROR_BAD_FILE ERROR:FILE FORMAT INVALID OR WRONG CODE:3020 This error occurs when DiskExpander is not able to handle a compressed file due to physical or logical error on the device. ERROR_OPEN_IMPOSSIBLE ERROR: UNABLE TO OPEN FILE CODE :3201 This error occurs during the attempt to open a file, when there is either not enough memory to allocate, or when the chosen compression library is not found. 4. THE COMPRESSION LIBRARIES 4.1 BASIC CONCEPTS DiskExpander does not contain a fixed number of pack algorithms firmly built into the program. The program uses a variable number of external libraries for compression purposes instead. This allows you to use different algorithms for different purposes, which provides you with optimal solutions for your specific problems. In Chapter 3 of this manual, the selection of a pack library for a device was explained. The following paragraphs will aid you to choose the right library by listing the advantages and disadvantages of the libraries that come along with DiskExpander. The different libraries are stored in the logical directory LIBS:, the same directory they are copied to during the installation process. When DiskExpander is installed to a Workbench disk, there will also be a directory LIBS: containing the libraries. A hard disk containing an installed version of DiskExpander will have the libraries stored in a directory LIBS: on the correct partition. As mentioned a few times before, DiskExpander can be used with a large number of libraries fulfilling the XPK standard. The XPK standard was developed by Urban Dominik Mueller, Bryan Ford and others. The compression routines implemented in these libraries can be used for a lot of purposes. You may use them in nearly every programming language, even in AmigaBASIC, if you need compression routines in your own programs. For this purpose we PAGE 18 have stored further information on the XPK standard and the libraries on the DiskExpander disk. You will find detailed documentation and information on how to call the pack routines from a programming language. The informational files are stored in the form of a LHA file and must be unpacked before you can use them. Due to copyright reasons, the well known LHA packer needed for that purpose is not part of the DiskExpander package. If you are in need of this packer, please take a look at some PD disks or download it from a mailbox. The complete XPK package is found on Fish disk 754. The XPKMaster library normally needed for the use of other XPK libraries is not necessary for the use of the libraries with DiskExpander. 4.2. THE LIBRARY EPU0 The library EPU0 was developed especially for use with DiskExpander. It is based on the LZSS algorithm, and its performance values are average. The algorithm uses a slow compression, but is fast enough for using with DiskExpander. The compression rate (the disk space gained by compression compared to the original file size) is also not the possible maximum, but quite useful depending on the format of the file to be compressed. There are better algorithms available as XPK libraries in term of speed as well as compression efficiency. Since the library EPU0 does not need much main memory as more efficient algorithms do, it may often be the best choice. The EPU libraries are not part of the XPK package. They differ internally from the XPK standard and may thus not be used in self-written programs the way it is explained in the XPK package. Please note the name of this library must be typed in lower case when using it with DiskExpander. 4.3. THE LIBRARY EPU1 In addition to the library EPU0 there is another library called EPU1 that was developed especially for use with DiskExpander. Unlike library EPU0, EPU1 is not a stand-alone compression library. It is used to provide an interface to the pack routines of the LH.library. The LH.library was developed by O.Barthel and P.Krekel and is not part of the DiskExpander package due to copyright reasons. You will find this library on PD disks (e.g. Fish 436). The LH.library contains a highly optimized Assembler version of compression routines used by the well known LHArc packer. The implementation of the Lzhuf algorithm has a very high compression rate and also excellent compression speed. For this reason, we have chosen to support the indirect use of this algorithm by DiskExpander. On Fish disk 436 you will find further information on the algorithm and some example programs that will help you use the LH/library in your own programs. PAGE 19 The name of the library EPU1 must also be typed in lower case to provide correct operation of DiskExpander. 4.4. THE LIBRARY NUKE NUKE is an XPK library that contains a highly optimized implementation of the well known LZ77 algorithm. This algorithm. This algorithm is used in a large number of other packers, such as PowerPacker or Imploder. The aim in developing this library was to provide efficient compression and fast decompression. The basic idea behind this packer was that most files are compressed only once and then decompressed (during read) a lot of times. Actually, this packer is excellent in regard to speed and efficiency, though not necessarily the optimal packer currently available. Data compression is not that fast, but the performance values are still good. To achieve these excellent compression rates, a large memory block has to be searched for identical byte sequences. If this search is successful, the position at which the sequence occurred together with the size of the sequence is saved, rather than the bytes themselves. Naturally this kind of search takes a lot of processor performance and also a lot of main memory. The developer of this library was able, though, to produce a polished implementation of the algorithm and thus achieves a compression speed of 35KByte per second on an Amiga 3000. As the algorithm needs a lot of main memory, this library should not be used on systems having less than 1 MByte RAM. Owners of 512K computers should use the EPU0-library or avoid extensive use of the multitasking system. To allow easy comparison of the different libraries belonging to the XPK package, performance statistics are given for each library. These statistics were produced using the standard XPK benchmark system (A3000/25 with SCRAM, compression of the AmigaVision program). METHOD PACKING UNPACKING PACKING UNPACKING COMPRESSION MEMORY MEMORY SPEED SPEED RATIO NUKE 192K 0K 35 K/s 613 K/s 45.2% Please note that the name of the library NUKE, as well as the names of the other XPK-libraries, must be typed in capitals when used with DiskExpander. 4.5. THE LIBRARY BLZW The XPK library BLZW is a highly optimized implementation of the popular LZW compression algorithm, also used in packers like ARJ and ZOO. While a lot of known XPK libraries were developed for fast data compression by assuming that most files are compressed only once and decompressed often, BLZW provides a high compression speed as well. This ability is highly interesting for an application like DiskExpander. PAGE 20 Thus, the library BLZW is an interesting alternative for those devices, where a lot of files are saved again and again, mainly data disks or hard disk partitions used for data storage. In those cases, we recommend the use of this library to avoid long waiting periods when saving files. We have a performance statistics for this library as well. The statistics were produced with the standard XPK benchmark system. METHOD PACKING UNPACKING PACKING UNPACKING COMPRESSION MEMORY MEMORY SPEED SPEED RATIO BLZW 30K 16K 134 K/s 356 K/s 32.4% Please note that the name of the library BLZW, as well as the names of the other XPK-libraries, must be typed in capitals when used with DiskExpander. 4.6. THE LIBRARY FAST The library FAST is another part of XPK package. Its main purpose is to be especially fast. Based on the LZRW1 compression routines (belonging to the family of LZ77-packers), this library actually achieves enormous speed in decompression, which makes it highly desirable for use with DiskExpander. In comparison to NUKE, the library FAST package achieves two times NUKE's decompression speed. Unfortunately a final version of the library FAST was unavailable when this manual was printed. Our test version only managed to pack about 20 KByte per second, but this should change in the final version, which may be included with DiskExpander. The programmer's goal is a compression rate of about 50 - 60 KByte per second, which would be double the compression speed of NUKE. The following performance statistics are presented in order to allow a comparison between FAST and the other XPK libraries. The statistics were produced with the standard XPK benchmark system. Please not that performance values may change in the final version of this library. METHOD PACKING UNPACKING PACKING UNPACKING COMPRESSION MEMORY MEMORY SPEED SPEED RATIO FAST 96 0K 426 K/s 1048 K/s 32.7% PAGE 21 4.7. ADDITIONAL LIBRARIES There is the possibility that some new pack algorithms will become available after this manual has been printed. In order to make them available to you, we will include them into the DiskExpander package as long as copyright makes this possible. They will be stored on the program disk; a documentation of the new libraries will be found in a file called "Read.me!". Please read this file in any case, because it may contain valuable information you will not find in this manual. For this reason, a general recommendation for one specific pack library is not possible. When this manual was ready for press, the library FAST was not available in a final version, so the XPK library NUKE produced the best results in speed as well as in compression rate. Following is a summary of the different XPK libraries that come along with DiskExpander. COMPRESSION RATE COMPRESSION SPEED DECOMPRESSION SPEED NUKE + + ++ BLZW 0 ++ + FAST + 0 ++ 0 = AVERAGE + = GOOD ++ = EXCELLENT 5. THE UTILITY PROGRAMS 5.1. DEVICEPACKER The utility program DevicePacker included in the DiskExpander software package was developed to allow compression of program and data files already stored on a device before the installation of DiskExpander. It is also possible to use the program for a data decompression or to compress the existing files using another library. DevicePacker creates a copy of the given file. This file may be stored in compressed or decompressed form, depending on the chosen parameters. The original file will be deleted afterwards, but the program is not limited to work on single files. You may use it on directories (including subdirectories, if you want to) and even whole devices. As mentioned before, DevicePacker needs DiskExpander to work correctly. Without DiskExpander already installed, DevicePacker is neither able to compress files nor to decompress them. DevicePacker can be run from the Workbench as well as from the Shell. When running the program from the Workbench, a graphical user interface appears on the screen, which allows a comfortable use of the program via the mouse. The same user interface will appear when the program is run from the Shell without any parameters. PAGE 22 *** See fig 5 *** The most important program parameters is the path to be compressed. You will find a string gadget in the user interface for that purpose. You may enter a directory name as well as a single file name into the gadget. It is not necessary to type the file or directory name; you can also click over the gadget left to the string gadget. A small file requester will be activated which allows you to choose the directory using the mouse. This file requester will be either the one included in the ASL library (or the ARP requester, if you are running Kickstart 1.2/1.3). If none of the two file requesters is available, the corresponding gadget cannot be chosen. *** See fig 6 *** When the path is selected, the gadget "Process files" can be activated, which starts the desired action for the chosen file or path. The status line displays the file actually handled. After all files have been handled, you may start the process again on another path, or you may exit the program by clicking on either the gadget "Quit program" or the close- gadget in the upper left corner of the window. In addition to the gadgets found in the user interface, the following functions are also accessible via the program menu. "Include Subdirs" in the menu "Preferences" selected whether DevicePacker shall automatically handle subdirectories of the selected directory. The option is on by default. PAGE 23 "Forbidden files" allows or forbids DevicePacker to create new versions of those files that must not be compressed by DiskExpander (as explained in Chapter 3.3.). this option is off by default (no tick next to the menu option). In case any of these files has been compressed by mistake, you will have to turn this option on and decompress the files again using DevicePacker. When the program is started from the Shell, it demands the path to deal with as command line parameter. If the additional parameter "ALL" is entered, DevicePacker will handle everything, including the subdirectories. In case no parameters are given, the graphical user interface appears on the screen. The parameter "?" returns a list of parameters possible at start from the Shell. To compress files already stored on a device please do the following: - Start DiskExpander from the selected device. The parameter "PACK" must be activated. The other parameters are not important, but we recommend not to change them the first time. - Start the program DevicePacker, preferably from the workbench, and select the device. - Start the compression process by clicking on the gadget "Process files". - When the compression is finished you may exit DevicePacker. If no errors occurred during this process, all files on the selected device are now stored in a compressed form. Please note that you cannot read these files without DiskExpander installed. If you want to decompress all files that were previously compressed with DiskExpander, you can also use DevicePacker. The procedure is as follows. - Start DiskExpander for the selected device. The parameters "PACK" must be turned off, while "UNPACK" must still be turned on. All other parameters are unimportant and should keep there values. - Start the program DevicePacker, preferably from the workbench, and select the device, the directory or even a single file. - Start the decompression process by clicking on the gadget "Process files". This might be useful when the Startup-sequence or the System- Configuration have been compressed by mistake. Use this function to cancel the mistake without loss of data. Another purpose of DevicePacker is to pack files that have already been packed before. This is useful when a new pack library is invented that gives better results in speed or efficiency, but your files are already compressed with an older library. in this case, do the following: PAGE 24 - Start DiskExpander for the selected device. The parameter "PACK" must be turned on, as well as the parameter "UNPACK". Enter the name of the new library into the string gadget "LIBRARY". All other parameters are without importance and should keep their values. - Start the program DevicePacker, preferably from the Workbench, and select the device, the directory or even a single file. - Start the compression process by clicking on the gadget "Process files". Now, all existing files will be decompressed using the old library and then compressed again with the new one. This ensures that your files can be packed with the best existing packer, even in the future. 5.2. DESTATISTICS To inform you about the practical use of DiskExpander at any time, we have included a program called DEStatistics into the program package. This program displays a lot of useful information about a file, for example the compression rate and the library used. If you want, DEStatistics can be copied to the DiskExpander directory during the installation. DEStatistics will display the following values: File name, physical and virtual size, compression rate (called pack rate) and the name of the library used for the compression. Additionally, the average sizes and compression rates are shown, in case DEStatistics is used on a group of files. *** See fig 7 *** The program DEStatistics can be started from the Workbench as well as from the Shell. When started from the workbench, a window with some gadgets for controlling the program via mouse appears on screen. Further, there is a equivalent menu option for any gadget. The most important gadget is the string gadget for the path. Use this string gadget to specify the single file or directory on which DEStatistics shall display information. As an alternative to typing the path, you can click on the folder gadget left to the string gadget. A small file PAGE 25 requester appears on screen and you can select the path via mouse. After the path has been set correctly, click over the gadget "Create statistics". DEStatistics now reads all the files in the chosen path, which can take a little time depending on the number of files. When the statistics have been produced, DEStatistics displays the calculated values in the central part of the window. In case the directory contains more files than can be displayed on screen at the same time, you can use the scrollbar, and the direction gadgets to move through the statistics. Directly below the single files data, the average values are shown. In addition to this, the pack rate is displayed graphically. To allow quick search for specific data, the statistics can be sorted according to file name, library name and pack rate. The menu "Preferences" contains the corresponding options "By Name", "By Library" and "By Pack Rate". When there is no demand for sorting, use the menu option "No Sort". A sort according to file name or library name returns the list files in alphabetical order of either the file names or the library names. A sort according to pack rate returns the files with higher pack rates at the top of the list. The default value is "No Sort", which displays the files in the order DEStatistics reads them. Use the menu option "Include Subdirs" in the menu "Preferences" to select whether the statistics shall contain subdirectories as well. This option is on by default. When DEStatistics is started from the shell without additional parameters, the user interface window appears on screen. If you start the program with path as parameter, the files in that path are read and their statistics values will be displayed in the Shell window. This output can be redirected to another device, for example to the printer. In this case, add the redirection command ">PRT:" to your command line. The whole command line looks as follows: DEStatistics >PRT: DH0:Pictures Statistics of the files stored in the directory "DH0:Pictures" will be produced and then displayed on the printer. If the additional parameter "ALL" is added to the command line, DEStatistics will display everything, including the subdirectories. The parameter "?" returns a list of parameters possible for a start from shell. 6. MISCELLANEOUS 6.1. HINTS FOR USING THE PROGRAM This chapter contains some hints that might be useful when working with DiskExpander and the utility programs. Since DiskExpander is a very flexible program, and therefore suitable for a lot of purpose, we can not propose the optimal solution for any possible purpose. We recommend experimenting a bit with the program's features. You should, for example, find out the compression library that is best suited for your specific purpose by testing all the libraries that come along with DiskExpander. This may be a different PAGE 26 library for any device or hard disk partition, depending on the kind of file stored there. The best way to find out the right library is the combined use of DiskExpander and DEStatistics. Use DiskExpander to compress all files on the device with the library you want to test. Then use DEStatistics to compare the average pack rate with those of the other libraries. the library returning the best values should be the one of your choice for this device. If you want to start DiskExpander on demand instead of having it started automatically by the Startup-Sequence, there is a comfortable solution which makes it easy to install or remove DiskExpander for a specified device. In this situation, the use of some icons on the Workbench is a good idea. As already explained in Chapter 3.2. ("Start from the Workbench"), ToolTypes may serve to set the different program parameters. So it is useful to create an icon for installing DiskExpander on a device and another icon for removing it. You may, of course, create any number of icons for other purposes simply by copying from the folder DEIcons and renaming them afterwards. Please note that the main program DiskExpander only needs to be stared on the device once. A new copy of the program for every icon is not needed. It is important to know that some files must not be compressed by DiskExpander. These include Startup-Sequence, the System-Configuration, the main file DiskExpander, the needed handler files stored in the directory L: and the pack libraries. In most cases, these files are stored on the boot device. To ensure that files will not be compressed by mistake, perform the following steps for the boot device: First install DiskExpander on the boot device using the pack library of your choice. The option PACK must be activated. Now compress all the files on the device using DevicePacker. Since the option "Forbidden files" is on by default, only those files that are allowed to will be compressed. When this process is finished successfully, all files will be compressed except the ones that are "forbidden". Start DiskExpander and select the boot device again. Turn on the option UNPACK and, this is very important, turn off the option PACK. Write this setup to the Startup-Sequence via "Modify Startup". From now on, no data on the boot device will be packed anymore, since the files are already compressed. A last note referring to the use of DiskExpander with packers like LHA and Zoo: It is of course, possible to use packers along with DiskExpander, but it is necessary to turn the options "Exam" and "ExNext" on. The packer programs compare the decompressed file size with the size of the file they produce to calculate their pack rate. This pack rate will note be correct if the two options are turned off. Some programs like "PasTEX", "Multiview", "Amiback 2.0B" and "Directory Opus 3.42" show problems concerning the "Exam" and "ExNext" option of DiskExpander. This is not a malfunction of "DiskExpander". We recommend to leave "ExNext" and "Exam" turned on generally to guarantee the cooperation between various programs and "DE". PAGE 27 6.2. SPECIAL NOTE TO KICKSTART 1.2/1.3 OWNERS Under the previous versions of kickstart the TrackDisk.device does not work correctly all the time. the most common error that may occur is that your Amiga does not want to read your original diskette and opens an requester with the following statement: INSERT DISPEXPANDER ORIGINAL-DISK IN UNIT 0 In this case we recommend to incorporate the call of TrackSalve into your Startup-Sequence. TrackSalve can be found in the "InstallData" drawer on your DiskExpander original disk and should be run with the following option: TRACKSALVE A Your original diskette will now be accepted without any problem. 6.3. FUTURE ENHANCEMENTS DiskExpander is being continuously upgraded. We plan to release version 3.0 of the program which will contain a lot of interesting new features. Some of these features we plan on including are: COMPRESSION METHOD ADJUSTABLE FOR SINGLE DIRECTORIES This makes it possible to compress only a part of a device. It also allows to compress different directories with different libraries. This is extremely useful because most pack algorithms were developed with a specific kind of data in mind (e.g. text or graphics). This feature will make it possible to pack a directory containing graphics with a library developed especially for that purpose. NEW PACK ALGORITHMS New routines for compression and decompression have been developed. These new routines often work faster or more efficient than old ones. We aim to include these new packers in the DiskExpander package. AREXX PORT IMPLEMENTATION The programming language ARexx allows DiskExpander's parameters to be changed from inside other programs. this is a major increase in flexibility. FUTURE UTILITY PROGRAMS We plan to include, a program for defragmenting the hard disk. This program would be able to clean up the whole disk and increase access time by optimally rearranging the files. LHA ARCHIVES We also plan to integrate the option of LHA archives into DiskExpander. PAGE 28 6.4. REGISTRATION Any owner of DiskExpander who returns the registration card will automatically be informed about new versions of the program. There will also be the possibility to receive updates. Register your program copy, because this allows us to inform you about the further development of DiskExpander. Please enter your personal data correctly. If you intentionally enter a nonsense name, you will lose the right to obtain updates. In case you have any ideas for additional program functions or enhancement of existing functions, please feel free to contact us. If your idea can be realized, we will include them in future versions of DiskExpander. PAGE 29