Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!mcsun!ukc!acorn!pcolmer
From: pcolmer@acorn.co.uk (Philip Colmer)
Newsgroups: comp.sys.acorn
Subject: Re: 1. Questions 2. Archivers in Comp.sys.binary 3. alt.language.wars ?
Message-ID: <5352@acorn.co.uk>
Date: 25 Feb 91 08:09:05 GMT
References: <8660@castle.ed.ac.uk>
Sender: pcolmer@acorn.co.uk
Distribution: comp
Organization: Acorn Computers Ltd, Cambridge, England
Lines: 51

In article <8660@castle.ed.ac.uk> aighb@castle.ed.ac.uk (Geoffrey Ballinger) writes:

>	Excuse me if I am being thick but I always thought that !Spark
>produced a compressed *binary* archive a la arc, zip, etc.,  while (if
>the above synopsis is correct) !submit/!extract produced an uncompressed
>*ascii* archive. If this is the case then we should use a combination of
>the two, i.e. !submit a !Spark-ed file. Anybody want to correct me?

Yeah, I will :-)

Both !Spark and !Submit/!Extract produce binary archives. !Spark produces an
Archimedes derivative of the PC ARC format. !Submit produces a UNIX tar file
- NB although !Submit uses Frank Lancaster's tar port and Frank has added
RISC OS support, !Submit does NOT use it, thus assuring full UNIX
compatibility.

After creating the binary archive, both applications produce uuencoded (ie
ASCII) versions, ready for posting.

The main differences are:

* Spark archives can only be read on RISC OS machines with the appropriate
version of Spark. This is because of the "changes" that David Pilling made
to the "specification" of an ARC file. This has drawbacks for people who get
their news via UNIX machines as it means that they cannot tell whether or
not they want to spend money downloading an article to their Archimedes
because it needs to be downloaded before they can tell what is in it. If we
use !Submit/Extract, this is not so much of a problem as the tar file can be
decoded on the UNIX machine first.

* anyone creating a Spark archive for posting as an article has to pay
PARTICULAR attention if the archive gets big because of the 100K mail size
imposed by most mail gateways. !Submit gets around this automatically by
knowing of this limitation and splitting uuencodings up to the appropriate
size.

* when you come to rejoin *multiple* articles, you need to strip the head
and tail off Spark articles (I believe). You don't need to for !Extract.

Of course, the above seems slightly (?) biased in favour of !Submit/!Extract
which is not too suprising since I wrote them ... but then I took care to
overcome many of the problems associated with posting articles to the news
system, which (after all) is NOT what !Spark was designed for in the first
place.

--Fil.

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