In answer to your questions:

1. "Core" (note: not _a core_, just _core_) is an old-fashioned term
   (from back in the days when dinosaurs roamed the earth) for computer 
   memory.  Back in those days, computer memories were actually made
   from tiny magnetic donut-shaped cores.  "Core" just means a copy
   of the program's memory.

   It is dumped - ie, copied to a disk file - so that someone with the
   requisite knowledge and tools (not me!) can take a look at it and
   maybe figure out what went wrong with the program.  A program's
   core is usually only dumped when something unexpected happens.

2. This one is much easier - NetBSD/Mac68k doesn't yet support the
   Mac's floppy drive, so there's no way to "format a floppy for
   NetBSD use."

3. An illegal instruction is just what it says:  the computer was
   trying to run your program and it ran across an instruction that
   it didn't understand.  A Sgementation Fault simply means that the
   program tried to access an area of memory that it shouldn't have,
   or tried to write into an area of memory that was marked for read-
   only access.

   Both of these conditions are frequent "something unexpected" that
   can result in core dumps.  (See #1).


Now, before you ask "Now that I know _what_ these things are, but _why_
are they happening to me?" you need to tell us a lot more about your
system.  What kind of Mac are you running NetBSD on?  How much memory
do you have?  What version of NetBSD are you running?  (Or, where and
when did you get the distribution?)  What is the rest of your system's
configuration?  Were you running in singe-user or multi-user mode?

The answers to these questions can best be answered by sending us the
output from the dmesg command.  If that command doesn't work, you'll
need to copy down _ALL_ of the stuff that NetBSD/Mac68k prints out
during the system startup, and then type it all back in.

HTH...

On Mon, 20 Jul 1998, Augey Mikus wrote:

> ok, i have now compiled a lit of problems i am having at the moment, thank
> you for your help.
> 
> 1. when typing "ps" there are a few errors that seem to revolve around the
> others when they choose, sometime the error is Segmentation Fault,
> sometimes its Illegal instruction, sometime not an error at all, mostly
> when there are errors there is a lot of core dumping. 
> 
> 2. when typing "df" segmentation fault. 
> 
> 3. when typing gcc, g++.... illegal instruction - core dump. 
> 
> 4. when typing ps aux .....lets just say it doesnt get past 3 prcesses.... 
> 
> Questions. 
> 
> 1. what is a core and why is it dumped? 
> 
> 2. how do i format a floppy to NetBSD usage? 
> 
> 3. what is an illegal instruction, and segmentaion fault? 
> 
> Sorry for the bother, and to all of you who take time out of their busy
> schedules to help someone new at Unix on a mac, full marks, and may you
> live a happy long and prospor life. :) 
> 
> Augey Mikus <mikus@flinet.com>
> 
> 

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