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From: dmurdoch@watstat.waterloo.edu (Duncan Murdoch)
Newsgroups: comp.lang.pascal
Subject: Re: TP Units
Message-ID: <1991Jun10.031607.5549@maytag.waterloo.edu>
Date: 10 Jun 91 03:16:07 GMT
References: <1991Jun9.150801.5178@minyos.xx.rmit.oz.au>
Sender: news@maytag.waterloo.edu (News Owner)
Organization: University of Waterloo
Lines: 22

In article <1991Jun9.150801.5178@minyos.xx.rmit.oz.au> s882023@minyos.xx.rmit.oz.au (Andy P [PB]) writes:
>Could someone please tell me how
>compatible Turbo pascal 5.5 units are with TP-6 ...
>also TP5.0 any (dos) versions really ..

The compiled units (i.e. .TPU files) are not compatible at all between
different versions of the System unit.  Every release of TP so far has had
a new system unit, and all but the last (TPW) had a new .TPU format as well.

If you have source code, things aren't so bad.  The changes from 4 to 5 and
5.5 probably won't cause you any trouble.  You'll only have trouble going
to 6.0 if
 - you have buggy code:  6.0 is less forgiving.  It requires that 
   assembler routines clean up the stack properly, and that you never
   try to dereference a pointer after you've disposed of it.
 - you have code that depends on the working of the heap manager.  It's
   quite different, so that'll have to be rewritten.  You're almost sure
   to get a compile-time error if this is the case, because Borland changed
   the names of some variables when their implementation changed.

Duncan Murdoch
dmurdoch@watstat.waterloo.edu