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From: sasaki@HARVARD.HARVARD.EDU.UUCP
Newsgroups: mod.computers.vax
Subject: BIO's vs. DIO's
Message-ID: <8701301208.AA01708@ucbvax.Berkeley.EDU>
Date: Thu, 29-Jan-87 23:43:56 EST
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Posted: Thu Jan 29 23:43:56 1987
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This is easy. The difference between direct i/o and buffered i/o is
that direct i/o goes directly from the device into your address space.
Data in a buffered i/o goes into a system buffer, which is then copied
into your address space.

Reverse the above for write operations.

From a practical point of view, disk i/o is direct (tapes too), while
terminal i/o is buffered.
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  Marty Sasaki				uucp:   harvard!sasaki
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