Xref: utzoo comp.sys.amiga.programmer:3263 alt.sources.amiga:221
Path: utzoo!utgpu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!think.com!mintaka!olivea!tardis!jms
From: jms@tardis.Tymnet.COM (Joe Smith)
Newsgroups: comp.sys.amiga.programmer,alt.sources.amiga
Subject: Re: Short Hello World
Summary: OK to depend on binary compatibility
Message-ID: <1804@tardis.Tymnet.COM>
Date: 6 May 91 05:41:39 GMT
References: <1991Apr30.213936.22878@ux1.cso.uiuc.edu> <1991May2.102554.8679@cs.umu.se> <1991May5.011748.11595@zorch.SF-Bay.ORG>
Reply-To: jms@tardis.Tymnet.COM (Joe Smith)
Organization: BT Tymnet, San Jose, CA
Lines: 33

In article <1991May5.011748.11595@zorch.SF-Bay.ORG> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes:
>dvljrt@cs.umu.se (Joakim Rosqvist) writes:
>> OpenLib=-408
>> Output=-60
>> Write=-48
>>   jsr    OpenLib(a6)
>>   jsr    Output(a6)
>>   jmp    write(a6)
>
>You've managed, in a 15 line program, to include 3 "magic numbers"
>that are dependent on the release of dos.library, so that your code need
>not merely be reassembled for an operating system upgrade, but rewritten.

I was about to post an article saying "don't be absurd, Kent.  If
Commodore were to change the library offsets, existing binaries would
stop working, therefore the offsets are engraved in stone; they will
never change."

But then I remembered that some of them HAVE changed.  OpenLibrary used to
be -408, now it is -552.  Offset -408 is still supported, however, as
OldOpenLibrary.  Using the old definitions is works, the program won't get
the newest features.

>Doing the linker's job for it is _not_ a smart move, as the first
>three lines clearly demonstrate.

Using the most recent *.h or *.i files is just as good as letting the linker
get the definitions out of amiga.lib.
-- 
Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com
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