Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!wuarchive!uunet!mcsun!corton!loria!loria.crin.fr!domen From: domen@wiener.crin.fr (Eric Domenjoud) Newsgroups: comp.sys.atari.st.tech Subject: Re: How does one relocate the Mouse ptr from pt A to B? Message-ID: Date: 4 Jan 91 15:04:44 GMT References: <9577@ncar.ucar.edu> <1990Dec20.100134.21871@qut.edu.au> <1990Dec24.131906.22082@qut.edu.au> Sender: news@loria.crin.fr Organization: CRIN, Nancy, France Lines: 23 In-reply-to: zseelunnon@qut.edu.au's message of 24 Dec 90 18:19:06 GMT In article <1990Dec24.131906.22082@qut.edu.au> zseelunnon@qut.edu.au writes: > Hmm! didn't know that one (I have TOS1.4) and have not seen this behaviour, > what exception does it cause ?. I have a pile of interrupt routines running > and occasionally get a spurious-interrupt exception generated (lotsa bombs ). > I would have thought that this change would have been atomic. > > Can you say B.U.G. ????? > > BTW - From memory the mouse vector is stored in a documented place > in the LINE-A variable set so I spose you could be more atomic about it > and do it yourself there ( At the risk of being TT incompatible I guess ) It does not cause an exception but simply crashes the ST. The problem is due to the fact that setting the mouse vectors lasts more than one cycle and thus may be interrupted. If the mouse moves while the vector is beeing setted, the mouse handler is called and the ST crashes because the vector is not a valid one. Try to write a program that calls vex_motv 10000 times and move the mouse. With TOS 1.0, it crashes. Eric Domenjoud e-mail: domen@loria.crin.fr