Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!uhccux!yuan
From: yuan@uhccux.uhcc.hawaii.edu (Yuan 'Hacker' Chang)
Newsgroups: comp.sys.mac.hardware
Subject: Re: 4Mb SIMMs (Really: Parity checking on IIci)
Message-ID: <6585@uhccux.uhcc.hawaii.edu>
Date: 14 Feb 90 02:22:16 GMT
References: <1446@key.COM>
Reply-To: yuan@uhccux.uhcc.hawaii.edu (Yuan 'Hacker' Chang)
Organization: Univ. of Barbarians.  Honolulu, Hawaii
Lines: 17

In article <1446@key.COM> russ@xanadu.key.COM (Russell Donnan) writes:
-
-First of all, let me say that I hate parity memory as much as the next
-guy...  BUT, I understand its usefulness.  A flipped bit where it doesn't
-count will not make you lose work in another area.  Parity is checked on
-a READ of memory.  So if you get a parity error, it is either your
-current application and associated data, or the Mac OS which had troubles.

	I thought parity is checked whenever the memory is refreshed.
After all, a refresh is pretty much a read-and-write cycle.  But then,
maybe it is much more efficient just to parity check memory that is being
read...
-- 
Yuan Chang 				      "What can go wrong, did"
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