From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,29f36805b9a20fe8
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2001-04-03 16:24:04 PST
Newsgroups: comp.lang.ada
Path: 
 supernews.google.com!sn-xit-03!supernews.com!cyclone-sf.pbi.net!63.208.208.143!feed2.onemain.com!feed1.onemain.com!europa.netcrusader.net!208.184.7.66!newsfeed.skycache.com!Cidera!news-reader.ntrnet.net!uunet!ash.uu.net!world!bobduff
From: Robert A Duff <bobduff@world.std.com>
Subject: Re: Streams in Ada
Sender: bobduff@world.std.com (Robert A Duff)
Message-ID: <wccn19x6032.fsf@world.std.com>
Date: Tue, 3 Apr 2001 23:21:52 GMT
References: <v7mx6.7111$MZ2.1190619@news2-win.server.ntlworld.com>
	<wccwv95fulm.fsf@world.std.com>
	<iq%x6.234$UK4.22262@www.newsranger.com>
	<tglmpjxutl.fsf@mercury.rus.uni-stuttgart.de>
	<9aa3dd$efb$1@nh.pace.co.uk>
	<tgofufwd4x.fsf@mercury.rus.uni-stuttgart.de>
	<zc1y6.352$UK4.34815@www.newsranger.com>
	<tgpuevurlk.fsf@mercury.rus.uni-stuttgart.de>
	<wccae5zw4hm.fsf@world.std.com> <9aakcq$kj9$1@nh.pace.co.uk>
	<87g0fqpa4b.fsf@deneb.enyo.de> <9acma8$d5k$1@nh.pace.co.uk>
	<87r8z9j1dw.fsf@deneb.enyo.de>
Organization: The World Public Access UNIX, Brookline, MA
X-Newsreader: Gnus v5.3/Emacs 19.34
Xref: supernews.google.com comp.lang.ada:6422
Date: 2001-04-03T23:21:52+00:00
List-Id: <comp.lang.ada>

Florian Weimer <fw@deneb.enyo.de> writes:

> "Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> writes:
> 
> > I suppose that may be what it would be if you thought of the *LARGEST*
> > addressable unit - but going the other direction is I think what was
> > intended.
> 
> No, the smallest unit which ordinarily hits the memory bus on the
> message I'm typing is 32 octets -- a cache line. ;-)
> 
> > AFAIK, Alphas will address a single byte
> 
> In standardeese, you're correct (a byte is commonly defined as the
> smallest addressable storage unit),

Perhaps nowadays, but in the old days, that wasn't true.  People talked
about "byte addressable", meaning you can address bytes (whatever that
means -- 8 bits?  something smaller than a word?).

>... but if you mean a single octet,
> I don't think so, AFAIK, the original Alpha CPU doesn't have this
> feature.  (Modern CPUs which also can operate in a PC-like environment
> probably have octet) Can anyone shed some light on this issue?

An address on the Alpha points to a single octet (8-bit byte).  The
original Alpha had no instructions for loading a byte, but I would still
call it an "addressable unit".  So on Alpha, an Ada compiler ought to
define:

    Storage_Unit = 8
    Word_Size = 64

- Bob