RCOMP/RDECOMP compressing/decompressing program About this software The author You can contact me as follows: E-Mail: Compuserve (CIS): 100116,3357 FidoNet: 2:301/811.26 Snail-Mail: Rolf Aeschbacher Bacheggweg 2 CH-8424 Embrach Switzerland Comments, bug reports, donations etc. welcome! Copyright, Disclaimer This program is FREEWARE. This means that you may spread it freely (unaltered, with all files included), but I will retain copyright to the code. Note that this is the first release of this program, it may contain bugs. I do not supply any warranty about its suitability for use. Installing Copy the two OPO files into any \OPO directory of your choice. To start, select it from the list under the RunOpl icon. RComp v 0.1 RComp compresses files using a flexible code algorithm (Huffman coding). You can use files of any filetype/content, however some files won't compress well or not at all. Typical reduction in filesize is about 20 to 30 percent. The process is very complex and it takes a lot of time to compress files in the OPL language. In C it would have been easier to program and would run several times faster - but unfortunately I don't have a C compiler... After the start of the program you are presented with a dialog where you choose the file to be compressed. The program then starts processing that file and keeps informing you what it's doing. Finally, it displays the filename that has been generated and which compression ratio has been reached. If however the compressed file should be larger than the original it tells you that and automatically deletes the .CMP file. Press any key to exit the program. The generated file will always have the extension .CMP. RDecomp v 0.1 This program reverses the compression done with RComp. First you have to choose a file to decompress. Only files with the extension .CMP are displayed (if you would like to see all files, press TAB twice, then DELETE and ENTER). After that, the program checks whether your choice is a valid file and then displays the original filename and filesize. Now it's up to you to decide about the two possibilities to decompress the file: a) Decompress to screen This is only suitable for files which contain pure ASCII. The file is decompressed 'on the fly' and displayed page by page. Press any key to see the next page. You can also press MENU for the following options: Psion-Z Zoom in, increase font size Psion-Shift-Z Zoom out, decrease font size Psion-P Show position in file Psion-A Display author info Psion-B Goto bookmark This tries to load a 'bookmark' file which has the same path/filename as the actual file but with the extension .CMB (see Psion-X about how to generate a bookmark). The text display then continues from where you stoped the last time. Psion-X Exit the program Before the program terminates it asks whether it should save the actual position in a bookmark file. Press ENTER the save a 'bookmark', SPACE to exit without bookmark, or ESC to return to the file display. b) Decompress to file This is faster than the output to screen. Use this choice for binary files (programs, WRD files, spreadsheets etc.) which contain characters that cannot be displayed. If the file to be generated alreday exists you are given the choice to overwrite that file or to abort the program. If anything goes right the file generated by RDecomp has exactly the same contents as the original file. Note however that checksums are not yet calculated - this means that a corrupted .CMP file would not be detected by the program. It is advisable to decompress the file again right after compressing and compare the two files before you delete the original file. This check can be done easily with another application available from me: CRC32, a program which computes the standard 32 bit checksum of files.