Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!cbmvax!daveh From: daveh@cbmvax.UUCP (Dave Haynie) Newsgroups: comp.sys.amiga.tech Subject: Re: Longword alignment with 68020 Message-ID: <6046@cbmvax.UUCP> Date: 22 Feb 89 17:58:16 GMT References: <27183@sgi.SGI.COM> Distribution: na Organization: Commodore Technology, West Chester, PA Lines: 28 in article <27183@sgi.SGI.COM>, scotth@harlie.SGI.COM (Scott Henry) says: > From article <6031@cbmvax.UUCP>, by daveh@cbmvax.UUCP (Dave Haynie): >> ... but data doesn't have to be aligned at all. > Does this mean that the 68020 will work with byte-aligned word and longword > data? Is there an echo in here? > No more odd-address traps on data? :-)? Is this, then another potential > incompatibility with the 680?0 series? You got it. It's an Amiga operating system requirement that word or longword data be word aligned, and, in some cases, longword aligned. It is not in any way a requirement of the 68020 or 68030 hardware. The reason for this is that the 32 bit CPUs have a much more clever bus sizing mechanism than the 16 bit ones. The 68020/30 can do other strange things, like running code out of 8 bit memory, that the 68000/10 can't. >> Dave Haynie ... > Scott Henry -- Dave Haynie "The 32 Bit Guy" Commodore-Amiga "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: D-DAVE H BIX: hazy Amiga -- It's not just a job, it's an obsession