Path: utzoo!attcan!uunet!fernwood!portal!atari!ataritx!dwh
From: dwh@ataritx.uucp (Dave Hanna)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: What do the Bombs mean?
Summary: Bombs mean an unexpected 68000 exception
Keywords: bombs exception
Message-ID: <1990Oct4.152607.3778@ataritx.uucp>
Date: 4 Oct 90 15:26:07 GMT
References: <`$R%X?_@rpi.edu>
Reply-To: dwh@ataritx.UUCP (Dave Hanna)
Organization: Atari Microsystems Corp.
Lines: 31

In article <`$R%X?_@rpi.edu> onders@degas.ipl.rpi.edu (Timothy E. Onders) writes:
>In particular, what do 3 bombs mean? Does anyone have a list of the
>different bombs?  

Bombs occur when the 68000 takes an unexpected exception trap.  The
number of bombs is equal to the exception number.  The more common
ones: 
    - 2 bombs is a bus error, usually occurring because you accessed
      non-existent memory, often because of using something as a pointer
      that wasn't a pointer, or wasn't initialized.
    - 3 bombs is an address error, meaning that you accessed a word
      or long word operand at an odd address.  May have similar causes
      to a bus error.
    - 4 bombs are an illegal instruction, which probably means your
      program took a wild jump an started executing data.
    - 11 bombs is an F-line emulator, meaning that your program tried
      to execute an instruction starting with the bits "1111...'.
      These instructions are reserved for the co-processor (which 
      doesn't exist in ST's.  It probably means your program took
      a wild jump into an area of memory that was filled with all
      FF's

If you see a large number of bombs, it may indicate that more than
one exception happened.
>					Tim Onders


-- 
    Dave Hanna    Atari Microsystems Corp
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