home *** CD-ROM | disk | FTP | other *** search
- #: 19823 S1/Help/Data Lib Tools
- 30-Jun-89 16:35:25
- Sb: #ARC & SDA Files
- Fm: Steve Sileo/Sysop 76703,4244
- To: [F] Bob Greenfield 73077,3602
-
- Bob,
-
- SDA stands for 'self-dissolving archive,' a fancy phrase perhaps, but nothing
- difficult.
-
- An archive is a file which is in reality one or more files squeezed together or
- compressed, and then stored as one unit. This makes it easier to transfer
- files. One needn't worry that one has downloaded all the necessary files to
- make a program work if all the necessary files are stored together.
-
- Archives (ARC files) are usually unpacked or uncompressed using the ARC utility
- (ARC230.BIN in CBMART's LIB1), but they can be made to un-arc all by
- themselves: self-dissolving or SDA. To use an SDA, simply download it as a
- program file, load it, and run it. It will then unpack all the files it
- contains and write them to disk.
-
- That's basically all there is.
-
- -steve
-
-
-
-
-
-
- #: 19847 S1/Help/Data Lib Tools
- 01-Jul-89 22:13:30
- Sb: #19823-#ARC & SDA Files
- Fm: Ted Bernhardi 70407,1346
- To: Steve Sileo/Sysop 76703,4244 (X)
-
- Steve,
-
- I think it's important to add that an SDA file does NOT need to have an
- extention of '.SDA', while a file that is ARC'd MUST have an extension of
- '.ARC' in it's name in order to be dissolved with the ARC.230 Utility.
-
- A lot of the difficulity arrises due to the fact that both types are named with
- a '.BIN' extension in the DL's.
-
- I would like to see a trend toward all files being SDA type files.
-
- Ted
-
-
- #: 19853 S1/Help/Data Lib Tools
- 01-Jul-89 23:38:10
- Sb: #19847-#ARC & SDA Files
- Fm: Ed Flinn/Sysop 76703,4032
- To: Ted Bernhardi 70407,1346 (X)
-
- Ted,
- That's interesting. Personally, I'm prejudiced against SDA files in favor
- of regular ARC. SDA files are always larger than a corresponding ARC would be,
- since each SDA, by definition, contains the deARCing program. SDA files are
- machine specific, either 64 or 128. This is probably mainly of interest to
- GEOS 128 users, since they can use most GEOS 64 files, but need to GO64 to
- dissolve a 64 mode SDA. 128 owners who have bought CS-DOS, the commercial 128
- version of ARC, can dissolve ARC files in 128 mode. Also, I've yet to find a
- program that'll let me build SDA files on a 1581. ARC itself trashes the
- directory of a 1581 when the ARC/A command is used, and the ARC <-> SDA
- programs I've seen don't know *what* to do with the lil wonder. All this is
- just my personal feelings, and shouldn't be taken as any kind of statement of
- the policy of this forum <grin>
-
-
- #: 19858 S1/Help/Data Lib Tools
- 02-Jul-89 00:50:49
- Sb: #19853-#ARC & SDA Files
- Fm: Ted Bernhardi 70407,1346
- To: Ed Flinn/Sysop 76703,4032 (X)
-
- One of the good features of SDA's is their ability to disolve repeatedly,
- and onto a different disk than the Archive.
-
- ARC'd prgms must disolve to the same disk that contains the Archive.
- To store the Archive disk means an additional step of transferring the
- dissolved files to a separate disk, and scratching them off the original.
-
- There is much more flexibility with the ARC utility, but for combining a
- game with some docs it usually
- isn't necessary.
-
- I like your disclaimer statement!
-
- Ted
-
-
- #: 19860 S1/Help/Data Lib Tools
- 02-Jul-89 01:44:36
- Sb: #19858-#ARC & SDA Files
- Fm: Ed Flinn/Sysop 76703,4032
- To: Ted Bernhardi 70407,1346
-
- Ted,
- Nope, ARC doesn't have to dissolve to the same disk as the input. For
- instance, assume input is MYFILE.ARC on drive 8, output to be on drive 9. The
- command sequence would be:
-
- c: (to make 9 current)
- arc/x a:myfile (to dissolve the input from 8)
-
-
- I have had some problems if one drive is a 1571 with a double-sided disk in
- it, but am convinced I could figure out how to deal with that, if I had the
- ambition <grin>
-
-
- #: 19861 S1/Help/Data Lib Tools
- 02-Jul-89 01:45:50
- Sb: #19860-ARC & SDA Files
- Fm: Ed Flinn/Sysop 76703,4032
- To: Ed Flinn/Sysop 76703,4032 (X)
-
- Oh yeah. The simple command
-
- arc/x a:myfile c:*.*
-
- or something like it should work regardless of the "current" drive, *but
- doesn't*. <shrug>
-
- #: 19862 S1/Help/Data Lib Tools
- 02-Jul-89 01:47:08
- Sb: #19860-ARC & SDA Files
- Fm: Ed Flinn/Sysop 76703,4032
- To: Ed Flinn/Sysop 76703,4032 (X)
-
- All of which is, of course, beside the point for users who only *have* one
- drive. They certainly benefit from SDA's.
-
- #: 19848 S1/Help/Data Lib Tools
- 01-Jul-89 22:20:04
- Sb: #19823-#ARC & SDA Files
- Fm: Ted Bernhardi 70407,1346
- To: Steve Sileo/Sysop 76703,4244 (X)
-
- Steve,
-
- One more question- Do you know if it matters whether an ARC or SDA file with a
- .BIN extension and downloaded with Vidtex needs to be processed using the
- 'XSTRIP' utility before being dissolved?
-
- Ted
-
-
- #: 19851 S1/Help/Data Lib Tools
- 01-Jul-89 23:18:50
- Sb: #19848-#ARC & SDA Files
- Fm: Steve Sileo/Sysop 76703,4244
- To: Ted Bernhardi 70407,1346 (X)
-
- Ted,
-
- I don't remember ever having to strip off the xmodem padding from an ARC or SDA
- file. Then again, I think I can count on one hand the number of files which
- just wouldn't work until I did strip 'em. Maybe I've just been lucky. Then
- again, maybe I just haven't downloaded enough files!!!
-
- -steve
-
-
- #: 19857 S1/Help/Data Lib Tools
- 02-Jul-89 00:38:09
- Sb: #19851-ARC & SDA Files
- Fm: Ted Bernhardi 70407,1346
- To: Steve Sileo/Sysop 76703,4244
-
- I haven't had any problems disolving either SDA or ARC files
- without doing any stripping first either.
-
- In theory all files D/L with Vidtex that are .BIN types ought to be
- run through the stripper prg first.
-
- However, as you said, I never do it unless it says it needs stripping in
- the file description (as does XTRIP.BIN).
-
- Most of the time the padding doesn't seem to affect the program
- at all.
-
- I just thought I'd check.
-
- Ted
-
- #: 19854 S1/Help/Data Lib Tools
- 01-Jul-89 23:40:30
- Sb: #19848-#ARC & SDA Files
- Fm: Ed Flinn/Sysop 76703,4032
- To: Ted Bernhardi 70407,1346 (X)
-
- Ted,
- As I remember, ARC is specifically built to be able to ignore Xmodem
- padding. SDA's would depend on the particular SDA program being used, but I've
- yet to see one fail because of padding. It is possible, I suppose, that a
- really large SDA could be pushed over the allowable size threshold by padding,
- but I haven't seen it happen.
-
-
- #: 19859 S1/Help/Data Lib Tools
- 02-Jul-89 00:52:17
- Sb: #19854-ARC & SDA Files
- Fm: Ted Bernhardi 70407,1346
- To: Ed Flinn/Sysop 76703,4032 (X)
-
- Nope, me neither.
-
-
- #: 19869 S1/Help/Data Lib Tools
- 02-Jul-89 11:16:48
- Sb: #19861-ARC & SDA Files
- Fm: Marte Brengle 76703,4242
- To: Ed Flinn/Sysop 76703,4032 (X)
-
- Yeah, I noticed that too! The drive whirred and it acted like it was
- dissolving, but the files never turned up anywhere, on any disk. Got me
- totally confused.
-
- I have also noticed that on occasion, when trying to un-ARC files on a GEOS
- disk, I will get a "dir error" message. I gather that the program is
- encountering the GEOS information and getting confused. Sometimes the stuff
- will un-ARC successfully and sometimes it won't. I've gone back to un-ARC-ing
- on a regular disk and then moving the files over to the GEOS disk. Takes a
- little extra time but saves a lot of aggravation.
-
- --M--
-
-