Path: utzoo!attcan!uunet!mcvax!cernvax!ethz!macman
From: macman@ethz.UUCP (Danny Schwendener)
Newsgroups: comp.sys.mac
Subject: Re: Why am I getting this sad mac?
Summary: microprocessors performing a double summersault
Keywords: sad mac errors bing
Message-ID: <606@ethz.UUCP>
Date: 11 Sep 88 13:52:09 GMT
References: <5026@netnews.upenn.edu>
Reply-To: macman@ethz.UUCP (Danny Schwendener)
Organization: ETH Zuerich, Switzerland
Lines: 35

In article <5026@netnews.upenn.edu> hodas@eniac.seas.upenn.edu (Josh Hodas) writes:
>My brother is having some trouble with my old mac now in his posession.
>This is a 512E upgraded with a Human Touch Computer Products (now defunct
>but I know their engineers) 3-2-1 board which features a 12 MHz 68000
>and an additional 1.5 meg of ram (for 2 Meg total).
>
>TOday for the second time in recent weeks while working in Pagemaker (not
>sure if its 2.0 or a more recent rev) he suddenly got a sad mac with 0f0003
>which on boot-up would be an illegal instruction trap.

If the sad mac code was 0F000D, it would mean that you touched the NMI
switch (also called "Programmer's switch" on the side of your mac. If
not, you're in big trouble.

Normally, an exception state interrupt is trapped and handled by the
System Error Handler routine SysError, which displays the bomb
alert on the screen. Debugger like Macsbug or TMON patch the trap
jump table to replace SysError by their own error handler.

In your case, the interrupt ("Illegal Instruction") has *not* been
handled in a normal way. This indicates either that a part of your system
jump table was clobbered, or that you have a hardware problem. If this
is the case, I'd guess that either your 3-2-1 board or the heat inside
the computer case may be the culprit (It's not the first time I'd see
a microprocessor performing a double summersault in an unfriendly
environment).

-- Danny

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