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Article #700Re: Difference between a 386 and a 386sx
From: Marc Brandis
Date: Wed, 26 Sep 1990 16:28
Date: Wed, 26 Sep 1990 16:28
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1236 bytes
Yes, there is a way to distinguish, but it involves measuring the time. Just do a long DWORD string instruction (like STOSD), do it once aligned on a dword boundary and once aligned on a word boundary but unaligned on a dword boundary (that is at the same address+2). Time both runs. On a 386DX, the time for these two access sequences differs quite a lot, as it needs one access for each doubleword in the aligned case and two in the unaligned case. On the 386SX, the times are the same as it requires two bus cycles anyway. (* I speak only for myself. Marc-Michael Brandis Institut fuer Computersysteme ETH Zentrum CH-8092 Zuerich, Switzerland e-mail: brandis@inf.ethz.ch brandis@iis.ethz.ch Temporarily at HP, marcb@hp-ptp.ptp.hp.com *)
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!sun-barr!cs.utexas.edu!sdd.hp.com!samsung!zaphod.mps.ohio-state.edu!swrinde!ucsd!ucbvax!hplabs!hpcc05!hp-ptp!marcb From: marcb@hp-ptp.HP.COM (Marc Brandis) Newsgroups: comp.sys.intel Subject: Re: Difference between a 386 and a 386sx Message-ID: <1310001@hp-ptp.HP.COM> Date: 26 Sep 90 16:28:36 GMT References: <1990Sep16.194605.11968@ecn.purdue.edu> Organization: HP Pacific Technology Park - Sunnyvale, Ca. Lines: 19