Orphaned Response

[tim at ISM780B.UUCP]

/* Written  7:23 pm  Oct 26, 1985 by guy at sun in net.unix-wizar */

don't think Motorola tells you 1) that it won't kill the system if you RTE
with arbitrary bits or 2) how to make sure that a bus error frame is safe.

/* End of text from net.unix-wizar */

If you want to see _wierd_ behaviour from a 68010, try changing the PC
in a bus error stack frame.

We had a case like this in the Callan Unistar 312 ( 68012 based box, running
a system V pageing system ).  We wanted to deliver a signal that a user was
wanting to trap, but we also want to rerun an instruction, since the reason
we are in kernel mode is that we have just finished a page fault.  By
experiment it was found that the 68012 is totally shpxrq(rot 13) by this.
We got around this with the trace bit.

				Tim Smith
				ihnp4!cithep!tim
				ihnp4!ima!ism780!ism780b!tim <- or something
								like that!