Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.sys.apple2
Subject: Re: One Byte Memory Reads
Message-ID: <13516@smoke.BRL.MIL>
Date: 9 Aug 90 21:54:23 GMT
References: <900808130731.2020095d@CCC.NERSC.GOV> <1990Aug8.202707.29249@laguna.ccsf.caltech.edu>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 14

In article <1990Aug8.202707.29249@laguna.ccsf.caltech.edu> toddpw@tybalt.caltech.edu (Todd P. Whitesel) writes:
>Weelll... in assembly it's a joke -- I don't know how the compilers handle it
>but in C you should be able to declare a char variable at a fixed address and
>the compiler will figure out that you want to do some byte-wide I/O.

C implementations are allowed to use wider access paths than logically
necessary to pick up the precise amount of data.  For example, a 16-bit
word could be loaded and the unwanted 8 bits masked off.  I don't know
what code existing Apple IIGS compilers actually generate for this.

>I don't know how you do this in APW/ORCA -- YET -- because I am fighting the
>impulse to order it as the official release of 1.1 approaches...

ORCA/C 1.1 has already been released.