Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!nosc!ucsd!ucbvax!CORY.BERKELEY.EDU!dillon From: dillon@CORY.BERKELEY.EDU (Matt Dillon) Newsgroups: comp.sys.amiga Subject: Another 68020 difference Message-ID: <8806240024.AA11802@cory.Berkeley.EDU> Date: 24 Jun 88 00:24:50 GMT Sender: daemon@ucbvax.BERKELEY.EDU Lines: 14 A friend of mine got caught by this one: BSET is atomic, right? OR.w #1,memory? wrong Guess what? The 68020 has no compunction for interrupting an instruction in the middle of its execution. So all those supposedly atomic single-instruction operations people have probably been doing, and not surrounding them with Forbid()/Permit(), create windows of vulnerability if you've got a 68020. -Matt