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Article #5221Re: Need help with 386 asm for 32-bit segments
From: Robert Collins
Date: Thu, 14 Mar 1991 20:44
Date: Thu, 14 Mar 1991 20:44
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1578 bytes
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 HOME: (408) 225-8002 WORK: (408) 432-6200 x4356
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Path: arc1-ca.pugleaf.net!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