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From: LEICHTER-JERRY@YALE.ARPA
Newsgroups: comp.os.vms
Subject: Re: Why no system() under VAX C
Message-ID: <8706182037.AA06476@ucbvax.Berkeley.EDU>
Date: Thu, 18-Jun-87 18:08:29 EDT
Article-I.D.: ucbvax.8706182037.AA06476
Posted: Thu Jun 18 18:08:29 1987
Date-Received: Sun, 21-Jun-87 15:52:00 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: <LEICHTER-JERRY@YALE.ARPA>
Distribution: world
Organization: The ARPA Internet
Lines: 45


    	1. WHY should layered products become dependant on the version
    	   of VMS.  BAD. 
    
Two reasons:  (a)  The layered product often depends on features new to some
particular version of VMS; (b) in the particular case of the VAX C OTS (and
other language OTS's), the OTS code ships with ALL VMS systems, so that you
can compile a C program and then run it on ANY VMS system, whether that system
has VAX C on it or not.  (This has always been the case for VMS languages
other than C; but C Version 1 didn't ship its OTS with VMS.  You then had
trouble - some technical, some licensing - moving compiled C code to systems
that didn't have the C compiler.  Bad news.)

The alternative is to ship the OTS with BOTH the layered product AND VMS.
This leads to all sorts of unpleasantnesses, as it becomes much more difficult
to determine what works on what system, and what should be installed on what
system.  For example, if the VAX C V2.3 kit containing the same OTS that
shipped with VMS V4.6 were installed on a V4.7 (or whatever) system, it would
replace a newer, presumably improved version of the OTS with an older one.

Despite the problems, this HAS been done on occasion, probably in cases where
new compiler features were so closely tied to new OTS features that it was
pointless to use the new compiler with the old OTS.  That's not the case with
VAX C - the new compiler will work perfectly well with the old OTS, since they
are not really too closely coupled.

    	2. Release notes are part of the installation procedure and no
    	   longer (for some time now) on hard copy.  Hey DEC,  how do
    	   we know if this product should be installed or not.  If
    	   you are telling us that VMS 4.6 is required to make use
    	   of VAX C 2.3, then I would not have installed this version
    	   yet.  Now your support group is saying that we should
    	   actually wait for VMS to catch up.  BAD.
    
When you try to install the product, you are asked whether you want to actully
install it, print the release notes, or both.  Just ask for "release notes
only".  (There may even be a VMSINSTAL option that does this - I don't remem-
ber.)

The advantage of having the release notes on the kit, instead of in printed
form, is that they can be more up to date - getting stuff printed has a long
lead time, but if you've changed ANYTHING on the kit, you have the opportunity
to change the release notes, too.
							-- Jerry
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