THE SPARK ARCHIVER

David Spencer takes a look at a Desktop archiver and file compressor.

Subscribers to the RISC User magazine disc may recall that in the past we have published two versions of a utility called Arc as a bonus item. Arc is a command line driven utility which both compresses and bundles together files. Given a set of files, Arc will combine them into a single file, the length of which will be less than the combined lengths of the individual files. The main use for which Arc is intended is in the downloading of files from bulletin boards and viewdata systems. These typically use archived files, especially with IBM PC programs, both because they take up less room, and also because it is much simpler to download a single file than a group of them. Because Arc is designed to cope with several standard archive formats, it is possible to decompress many files with it, though the actual decompressed files may not be of much use if they are for another system. Now, David Pilling who implemented Arc on the Archimedes, has followed the RISC OS philosophy and developed a multi-tasking Desktop version called Spark.

When Spark is installed, it places an icon on the iconbar. Pressing the Menu button over the icon offers Quit and Info options, and a New archive option. Selecting this pops up a save box from which to create an empty archive. Archive files are represented by a picture of Noah's Ark. Dragging an archive onto the iconbar icon will open a pseudo directory viewer, and new files can be added to the archive by dragging them into this viewer. Similarly, file are recovered from the archive simply by dragging them out. Menu options allow you to change the archive format, and the archiving method, so that it is possible, for example, to archive only files that are newer than the version already in the archive. Other options allow the archive to be encrypted using a password, and the integrity of the archive checked to see if the files are all readable.

DOCUMENTATION

The 'user guide' comes in the form of a text file on the disc and a short application to display it. These notes detail how to use Spark, and any possible problems. While they are relatively short, they are perfectly adequate for what is a very easy-to-use product.

BONUS ITEMS

Included on the Spark disc are a couple of public domain programs. The first of these is the RISC User Dustbin which was originally published on the magazine disc for Volume 2 Issue 6. For readers who haven't seen it, this allows files to be deleted by dragging them into the bin. The second bonus item is a utility to make the Desktop 'sticky'. This allows objects to be dragged out of directory viewers and placed anywhere on the Desktop background. Thereafter, the system will remember where the object came from (and hence actually is), and there is even a facility to save the Desktop so that when it is restarted all the objects are there. While at first sight this appears to be a very useful utility, it suffers from the major drawback that it falls over if the original of any file on the Desktop is deleted, moved or renamed.

CONCLUSION

I can see two main reasons why people would use Spark. Firstly, for its original purpose of packaging files for transfer via modems, and secondly for compressing files when making an archive, or a backup, of a hard disc. In the first case, Spark performs the task with ease. However, although the file compression is very good (in terms of space saved), each archive file has to fit on a single floppy. Therefore, to make a backup of an entire hard disc, it is much simpler to use a dedicated backup utility. Whatever your needs, if you feel that Spark would be useful, then you really can't go wrong at under £6.
ProductSpark Archiver
SupplierDavid Pilling
 PO Box 22,
 Thornton Cleveleys,
 Blackpool FY5 1LR.
Price£5.95 inc. VAT and p&p