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From: ONM07@DMSWWU1A.BITNET (Julian Reschke)
Newsgroups: comp.sys.atari.st
Subject: Re:  POOLFIX4 and the XBRA Standard
Message-ID: <9004090954.AA05031@freya.math.dmswwu>
Date: 10 Apr 90 07:05:29 GMT
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X-Unparsable-Date: Mon, 9 Apr 90 12:54:13 MSZ

In article <22912@watdragon.waterloo.edu> anthony howe writes:
> Hmm. I think I have not been paying attention again and missed
> something important on the net. Being a developer and not having a
> complete set of docs bothers me to no end.
>
> What is the XBRA standard as mentioned in the POOLFIX4 article? Is
> there a blurb on how to it is done? Can some kinf soul send it to me
> please.
XBRA is based on a old proposal by Moshe Braner (hence the name, 'eXtended
BRAner'). It is a protocol for programs for revectoring system vectors
and looks like this:

        dc.b    'XBRA'  ; magic number for 'xbra was used'
        dc.b    'FOOB'  ; 4 characters unique id for the program (should
                        ; be printable characters, id's starting with '_'
                        ; are reserved for Atari)
oldvec: ds.l    1       ; contains old value of the changed vector
newvec: ...here goes the new code...

Using this protocol, programs can:
- find out, if they are already installed
- follow a vector chain up to the start

This protocol is officially documented by Atari Germany and is used
in ca. 100 german programs.


___________________________ cut here _____________________________________
Julian F. Reschke, Hensenstr. 142, D-4400 Muenster, Phone: ++49 251 861241
eMail: ONM07@DMSWWU1A.BITNET, "Julian Reschke" @ MAUS MS  (++49 251 77216)
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