Xref: utzoo comp.unix.questions:19891 comp.unix.wizards:20590
Path: utzoo!utgpu!watserv1!watmath!att!dptg!lzga!bogatko
From: bogatko@lzga.ATT.COM (George Bogatko)
Newsgroups: comp.unix.questions,comp.unix.wizards
Subject: bus errors - thanks
Message-ID: <1818@lzga.ATT.COM>
Date: 14 Feb 90 02:26:30 GMT
Organization: AT&T BL Middletown/Lincroft NJ USA
Lines: 38


Thanks to all for the help with the bus errors.  I was somewhat relieved
to see that it was not such a naive question after all.  The problem cropped
up during hardware changes (phone switch related), and may be a new
garbage message (hence the missing NULL byte), or a perhaps a real 'BUS' error.

**********

Incidently:

main()
{
char x[8];
long y;
long z;

	y = 0xaabbccdd;
	memcpy(x, &y, sizeof(long));
	memcpy(x+4, &y, sizeof(long));
	z = *(long *)(&x[1]);  /* kaboom? */
	printf("z=%#x\n", z);
	return 0;
}

prints:  
	SysVr2.0   vax-8600: 0xddaabbcc

	SysVr3.1   3B4000:   EMT Trap -|
	SysVr3.1   3B600:    EMT Trap  |--same guts
	SysVr3.2.1 3B600:    EMT Trap -|

	SysVr3.5   UNIXPC:   Bus Error

I don't have access to a 6386 machine at the moment.

Thanks again

GB