Article View: comp.sys.ibm.pc
Article #8814Re: 32-bit addressing on the 80386 in real mode?!?
From: Ralf.Brown
Date: Thu, 18 Jan 1990 12:32
Date: Thu, 18 Jan 1990 12:32
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1392 bytes
In article <1990Jan18.055726.20604@wam.umd.edu>, walrus@wam.umd.edu (Udo Karl Schuermann) wrote:
}produces a 4 GByte address range. In real mode, the registers are only
}16 bits long, and in addition, the segment and offset registers overlap
}such that the total number of bits used is not the sum of 16 + 16 being
}32 bits but only 20. This has the unfortunate (and often confusing)
}side-effect of giving you 16 different addresses for each byte in the
}real mode address space.
Actually, that's 4096 different addresses for each byte....
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!pt.cs.cmu.edu!b.gp.cs.cmu.edu!Ralf.Brown@B.GP.CS.CMU.EDU From: Ralf.Brown@B.GP.CS.CMU.EDU Newsgroups: comp.sys.ibm.pc Subject: Re: 32-bit addressing on the 80386 in real mode?!? Message-ID: <25b5c57c@ralf> Date: 18 Jan 90 12:32:44 GMT Sender: ralf@b.gp.cs.cmu.edu Organization: Carnegie Mellon University School of Computer Science Lines: 16 In-Reply-To: <1990Jan18.055726.20604@wam.umd.edu>