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From: johnl@ima.ISC.COM (John R. Levine)
Newsgroups: comp.sys.ibm.pc
Subject: Re: MASM Question
Message-ID: <719@ima.ISC.COM>
Date: Fri, 25-Sep-87 16:01:48 EDT
Article-I.D.: ima.719
Posted: Fri Sep 25 16:01:48 1987
Date-Received: Sun, 27-Sep-87 03:02:10 EDT
References: <1617@killer.UUCP>
Reply-To: johnl@ima.UUCP (John R. Levine)
Organization: Not enough to make any difference
Lines: 24
Keywords: Align type PAGE

In article <1617@killer.UUCP> tad@killer.UUCP (Tad Marko) writes:
>I was flipping through my Microsoft MASM manual (I'm trying to learn
>80x86 ASM), and I noticed an align type PAGE (256 byte alignment).
>What I want to know is, WHY?  

Three guesses:

A) Some kinds of ROMS used to come in 256 byte sizes, this would make it
	easier to write ROMable code.
B) Some kinds of disks used to have 256 byte sectors, this would make it
	easier to assemble grotty boot programs.
C) When the original programmer was writing the first 8086 assembler, he
	was used to some previous micro like the 8080 where eight-bit
	offsets were used, and he implemented and documented it before 
	someone noticed that it was useless on an 8086.

The astute reader will note that you can get any alignment you want by
use of the .ORG pseudo-op, so ALIGN is no more than syntactic sugar in
any case.
-- 
John R. Levine, IECC, PO Box 349, Cambridge MA 02238-0349, +1 617 492 3869
{ ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.something
The Iran-Contra affair:  None of this would have happened if Ronald Reagan
were still alive.