Path: utzoo!attcan!uunet!samsung!sdd.hp.com!decwrl!bacchus.pa.dec.com!deccrl!shlump.nac.dec.com!engage.enet.dec.com!ynotme.enet.dec.com!wallace From: wallace@ynotme.enet.dec.com (Ray Wallace) Newsgroups: comp.sys.atari.st.tech Subject: Re: What do the Bombs mean? Message-ID: <2089@engage.enet.dec.com> Date: 4 Oct 90 16:11:41 GMT Sender: news@engage.enet.dec.com Organization: Digital Equipment Corporation Lines: 55 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? I used to have one but I can not find it now. The number of bombs is equivalent to the number of the 68000 exception which occured. Note that if the ST gets an error while (or just after) it is drawing bombs, it will sometimes draw bombs for the 2nd error as well (on the same "line"). For example if you see 11 bombs it is most likely that two errors occured, for example; 5 bombs followed by 6 bombs. -< Description of BOMBS >- -------------------------------------------------------------------------------- This description of ST bombs was originaly posted to the Usenet by Andie Ness. I've added a comment on large numbers of bombs. Here's a list of what the various numbers of bombs mean... 1 - Impossible. If you get 1 bomb, take your ST to a repair shop. 2 - Bus error. This means you have tried to access memory outside the computer's valid address space (or tried to access a protected area in user mode). 3 - Address error. This usually results from doing a word or long operation on an odd byte boundary. 4 - Illegal instruction. You figure it out. 5 - Divide by 0. Usually generated by the divs and divu instructions, though if I recall correctly some others can cause it as well. 6 - CHK instruction trap. If a chk instruction returns an illegal value, this trap is executed. Chk is actually pretty dumb, in my opinion, unless you're using Pascal. 7 - TRAPV instruction. You get this by executing a trapv instruction when the overflow bit is set. Most programs don't use trapv, so this one shouldn't pop up much. 8 - Privilege violation. This one appears when a supervisor-only instruction is encountered in user mode. 9 - Trace. If you've got the trace bit set, this trap will occur after each instruction. Great for debuggers. 10 - Line-A. You shouldn't get this, as it's the interface Atari uses to get to graphics routines. 11 - Line-F. This is supposed to be a hook for math coprocessors, but Atari (DRI?) used it for GEM instead. I would have preferred a coprocessor. The others are pretty much undefined; if you get one, something weird is going on. From 32 to 47 bombs mean that you made a trap call whose vector wasn't set. --- Ray Wallace (INTERNET,UUCP) wallace@oldtmr.enet.dec.com (UUCP) ...!decwrl!oldtmr.enet!wallace (INTERNET) wallace%oldtmr.enet@decwrl.dec.com ---