Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!think!bloom-beacon!apple!well!ewhac
From: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Longword alignment with 68020
Message-ID: <10803@well.UUCP>
Date: 22 Feb 89 10:07:25 GMT
References: <712@cord.UUCP>
Reply-To: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
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Quote: "I'm not wearing any pants...  Film at eleven."  -- Kentucky Fried Movie

In article <712@cord.UUCP> nsw@cord.UUCP (Neil Weinstock) writes:
>Do the 68020/32-bit memory boards (ala A2620) require that longword data
>be longword-aligned?  [ ... ]
>
	No.  You will achieve optimum performance if you do align your
logwords/pointers on longword boundaries, but you'll still be able to fetch
longwords on arbitrary word boundaries.

	As an extra added bonus, the '020 will read and write words on odd
*byte* boundaries (but you pay a heavy performance penalty).  An entire
class of Gurus almost disappears!  (Type 00000003, Address error.)

>(The blitter requires its data word-aligned, right?  That has been my
>experience.)
>
	Yes.

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Leo L. Schwab -- The Guy in The Cape	INET: well!ewhac@ucbvax.Berkeley.EDU
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