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- Help for !CBAdecode (version 1.01)
- ==================================
-
- * This program is FREEWARE
- * You may copy/distribute it as much as you like so long as it is not
- * copied or distributed for profit, or as part of a commercial product.
- * Use (of application and source) is entirely at your own risk.
- *
- * This program uses calls and source code from the DeskLib library
-
- This application is designed specifically to make decoding
- comp.binaries.acorn postings easier and quicker. It will NOT work with
- postings to other usenet or FidoNet groups! (This is because it relies on
- some header data that we place when we post files, which cannot be expected
- in other groups)
-
- This application can be run in two ways:
- (Impressive, huh? How many other RISC OS applications do you know which
- can do this? (Not that any others would need to...))
-
-
- From the desktop
- ================
-
- Double-click the !CBAdecode icon. A window should appear.
-
- Drag any files that you wish to decode to the window (The order in which you
- do this is not important).
- You can also drag a directory to the window, and all files inside that
- directory (but NOT any files in subdirectories of it) will be scanned.
-
- => And now you can drag files from another application (i.e. your
- => newsreader) as well (please see the note at the bottom of this file
- => before trying this option!)
-
- As each file is given to the application, it is scanned to find any valid
- cba posting parts in it. For every valid posted binary found, an icon that
- looks like an archive file icon (Displayed as "Full Info") will appear.
-
- The information on this line indicates the name the post will be saved as,
- the approximate size (actually, it is the correct size, rounded UP to the
- nearest 37 kilobytes) that it will be when decoded, and the number of parts
- that have been found out of the number expected.
-
- When some but not all of the parts have been found, the icon will be grey
- and unselectable. Once all the parts have been found, the file will be
- automatically selected.
-
- This initial scan is non-multitasking, but usually takes less than a second
- on an Arm-2 machine to scan a typical 50kB post message file from a fast
- hard drive. From fast file media (ramdisc/hard drive) the operation is
- pretty quick, and from slow media the desktop response would be very
- sluggish, so you'll have to put up with it singletasking for now...
-
- Once all files have been found (the icon will become a coloured one rather
- than greyed out, and will automatically be selected (inverted)), you are
- ready to decode the file.
-
- To decode files, select the ones you want, just as in a normal filer window,
- and drag them to any filer window. Don't drag them to an application,
- because this won't work! (It appears to save into the CSD but don't count on
- this property! New versions of the application might try to do something
- clever like actually passing the decode file to the app.) As soon as you
- complete the drag, uudecoding will begin.
-
- This uudecoding phaze is conducted in the background on the desktop. This
- means that most of the time you shouldn't notice its operation too badly,
- except where filing operations are slow (this is particularly noticable when
- it is necessary to swap files). The main reason that this multitasks is so
- that you can see its progress, and so that you can hit the close-window icon
- to quit (and thus abort the operation) at any point.
-
- If a file of the same name as the attempted output file (called, e.g.
- "file") exists, names A_file, B_file, C_file ... will be tried. If Z_file
- is reached (very unlikely) without finding a unique filename, then
- the attempt will be aborted completely.
-
- If you wish to clear the list of files and start fresh, bring up the menu,
- and click on "Clear files". The menu also has an info window and a quit
- option.
-
- To quit, use the quit on the menu, or simply close the decoder window.
-
-
- From the command-line (Archimedes or UNIX)
- =====================
-
- Run the application with the syntax:
- CBAdecode [options] [list_of_filenames]
-
- e.g.
- CBAdecode csa.95 csa.96 csa.97 (Archimedes)
- CBAdecode csa/95 csa/96 csa/97 (UNIX)
-
- NOTE: Currently, you CANNOT give a directory name or any wildcarded
- filenames to the command-line version.
-
- Any complete and valid postings found will be decoded immediately, exactly
- as in the WIMP version, but without the fancy WIMP features. Decoded files
- will be placed into the CSD (currently selected directory)
-
- CBAdecode has two command-line flags:
- -d Sets desktop operation mode. This manke CBAdecode try to start
- up as a desktop task. It should only be used in the desktop
- !Run file. DO NOT use it from within a taskwindow!
- -b <size> Sets the input and output buffer size. Specified in terms of
- kilobytes. The default value is 16 (16 kilobytes), which
- results in an extra 32k (2 buffers) being needed.
- Values <= 4 will result in operating-system buffers being used
- (as these are 4k anyway), but will cause a lot of disc
- seeking, which slows down operation on floppies considerably.
- Values > 64k will not make much of a difference unless all
- posted parts are contained in one large input file.
- Values outside the range 0..128 cause an error.
- Note also, that if memory is not available for the buffers,
- only operating-system buffers will be used (so if you specify
- too large a value, it will drop back to 4k buffers)
-
- (The -b flag is used in the !Run file for desktop operation, and can also be
- changed to a default you are happier with)
-
- Operation
- =========
-
- The way the program scans for parts means that you do not need to delete
- message headers and signatures, concatenate files, or even get them in the
- right order - everything is done automatically for you!
-
- In fact, if you do strip headers, the program will FAIL, so just leave the
- message files you get from c.b.a alone, and pass them to this program in
- their RAW, unprocessed form.
-
- The application will cope with all of the posted messages concatenated into
- one (or more) file(s), or a lot of seperate files.
-
- It also handles any mixture of parts from different postings without
- complaint.
-
- The only thing it won't currently handle is a posting with more than 32
- parts in it (which is a 1.6 Megabyte posting...). However, such a large
- posting will produce an archive file of approximately 1MB, which is a bit
- big for many people to handle anyway, so it is extremely unlikely that
- binaries larger than this will be posted on c.b.a. in one archive chunk.
-
-
- Problem shooting
- ================
-
- Don't shoot problems. It's antisocial. (Bdooom-Tsh!)
-
- What can you do wrong? Here's a list:
- (There are 2 types of error - warnings, which indicate possible problems,
- but usually don't affect the outcome of the decode (which are not even
- reported under the WIMP), and bad errors, which will cause the application
- to abort its attempt to decode that particular posting. (Some very bad
- and unlikely errors may even cause the application to quit)
-
- * Not all parts present
- You will not be able to decode a posting until files containing all the
- relevant parts have been supplied. (These incomplete postings are shown on
- the desktop in grey)
-
- * One or more parts duplicated
- The duplicate parts are ignored without comment. (actually, on the
- commandline a warning is given, just ignore it)
-
- * The quoted total number of posted parts changes from one part to another
- Processing of that posting will abort, and the next posting will be
- started. This shouldn't happen unless the messages get corrupted or
- you happen to get 2 different postings under the same name (unlikely!)
-
- * Too many parts in the posting
- The application thinks there are supposed to be (eg) 5 parts in the
- posting, and it has found a part number less than 1 or greater than 5.
- This usually indicates corruption of some of the files.
-
- * Filing errors
- If any problems occur when trying to read or write any files (most likely
- because an input file wasn't found or because the disc is full), the
- application will abort.
- For disc full errors, try decoding only a single post at a time, and
- if necessary, decode to a different disc than the source files are on
- (note that this will require disc swapping unless using 2 drives or a
- RAMdisc)
-
- * UUcode errors
- These are usually fatal (uucode is either right or wrong), and are usually
- caused by parts of the uucode data being corrupted or missing. There isn't
- much that can be done about this - try to get a new copy of the offending
- files.
-
- If anything goes wrong, what can you do to fix it?
- * Check that you are giving it the correct set of files, and try again.
-
- * If you still can't get any joy, then you will have to resort to decoding
- the file by hand - strip headers and footers, concatenate all the text
- together in the correct order, and use Spark, SparkFS, or uudecode
- to decode the file.
-
-
- Decoding files direct from other applications
- =============================================
-
- If you drag a file to !CBAdecode from other applications (Edit or a
- newsreader most likely), then CBAdecode will save the file as
- !CBAdecode.temp.<number>
- This temporary file will be used when you subsequently drag archives out to
- a filer window.
-
- When you next quit !CBAdecode, ALL files in the !CBAdecode.temp directory
- will be wiped. This includes any parts that have not been used.
-
- DON'T delete your original messages until you have a complete, working
- archive from CBAdecode - don't expect CCBAdecode to keep the file for you!
-
- *FUTURE* versions of CBAdecode may be upgraded to keep any parts that have
- not yet been decoded successfully, so that you can just drag in any new
- messages and 'skim off' any completed postings...
-
-
- The author
- ==========
-
- If you have any bug reports or suggestions to send to the author, or if you
- want to offer him an extremely highly paid job and a Porsche (preference,
- black 930 or 944), write to:
-
- * Jason Williams
- * R.D.2, Manuel Road,
- * Silverdale,
- * North Auckland,
- * NEW ZEALAND.
- *
- * jwil1@cs.aukuni.ac.nz
- *
- * (Moderator of usenet groups comp.binaries.acorn and comp.sources.acorn)
-
- P.S.
- ====
-
- Apologies for the humour - I'm in a good mood today ;-)
-