Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!sdcsvax!ucsdhub!hp-sdd!hplabs!hpcea!hpfcdc!hpfcrj!bayes From: bayes@hpfcrj.HP.COM (Scott Bayes) Newsgroups: comp.sys.mac Subject: Re: I've heard of disclaimers but this is ridiculous Message-ID: <3940002@hpfcrj.HP.COM> Date: 15 Dec 87 19:59:29 GMT References: <7006@apple.UUCP> Organization: HP/SSO Ft. Collins, CO. Lines: 30 >The third paragraph of section 8.4 (page 8-22) in a current 680x0 >manual states, and I quote, > > "The system software should not depend on a particular > exception generating a particular stack frame. For compatibility > with future devices, the software should be able to handle > any type of stack frame for any type of exception." > >HELLO?? WHAT THE HELL DOES THAT MEAN???? >Seems just a bit "too" general for me. Isn't it a bit late in the game >to publish such a general disclaimer on the part now??!?!! Does this mean >I have to go back and rewrite all the exception handlers I've ever >written for the 680x0 parts and turn them into psychic AI modules? >How can I write an exception handler and NOT depend on what the exception >stack frame looks like? I couldn't find the reference in my 68020 manual. I'm guessing it means you should check the frame format word, and from that you can find the nature of the frame data. I believe I remember hearing that the 68882, for example, may generate a larger, different frame for the same co-processor exception that the 68881 could generate. We have a bit of code that does something on the edge of assuming that a given exception has a given frame; we'll have to turn the handler involved, should we support the 68882. Disclaimer: the opinion expressed above is my personal opinion, and does not reflect an official position of Hewlett-Packard Co. Scott Bayes hpfcla!bayes