Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!altos!altos86!rcollins
From: rcollins@altos86.Altos.COM (Robert Collins)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Need help with 386 asm for 32-bit segments
Message-ID: <116@altos86.Altos.COM>
Date: 14 Mar 91 20:44:42 GMT
References: <91071.130848REIDMP@MAINE.BITNET>
Reply-To: rcollins@altos86.UUCP (Robert Collins)
Organization: Altos Computer Systems, San Jose, CA
Lines: 22

In article <91071.130848REIDMP@MAINE.BITNET> REIDMP@MAINE.BITNET (Reid M. Pinchback) writes:
>Though I've done enough 86/286 asm in past, I'm new to the 386.
>I've scanned assorted books/manuals on 386 asm.  I want to use
>32-bit segments, but I'm not sure how to set them up.  
>Can this be done in real mode, or do I need to go to all the grief of
>figuring out how to cope with protected mode?

The 32-bit segment flag is only contained in a '386 descriptor table entry.
Therefore, you must be in protected mode to execute 32-bit code.  You
can use 32-bit operands in real-mode simply by using a 'USE16' segment
and write code using 32-bit operands.  32-bit code is different than
using 32-bit operands.  32-bit code, in addition to defaulting to 32-bit
operands, uses different encodings on some of the CPU instructions.
Therefore there is a need to tell the compiler which version of the
opcodes to compile.


-- 
"Worship the Lord your God, and serve him only."  Mat. 4:10
Robert Collins                 UUCP:  ...!sun!altos86!rcollins
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