From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.4 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 20288 invoked from network); 3 Feb 2021 23:47:03 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 3 Feb 2021 23:47:03 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 239959C8D9; Thu, 4 Feb 2021 09:47:02 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id E70239BA47; Thu, 4 Feb 2021 09:46:37 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (1024-bit key; unprotected) header.d=ieee.org header.i=@ieee.org header.b="gMNpbzEI"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 5E92A9BA47; Thu, 4 Feb 2021 09:46:34 +1000 (AEST) Received: from mail-lf1-f53.google.com (mail-lf1-f53.google.com [209.85.167.53]) by minnie.tuhs.org (Postfix) with ESMTPS id B038C9BA40 for ; Thu, 4 Feb 2021 09:46:32 +1000 (AEST) Received: by mail-lf1-f53.google.com with SMTP id a8so1773754lfi.8 for ; Wed, 03 Feb 2021 15:46:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ieee.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=dq/7849gDX+0ySMh2NKeki4IKSTMdZkd94H6sy4OGfM=; b=gMNpbzEIF9yofXbc/qkGgL8COy1NcvTNBW7ST1voLjNotZdtT2LHeF1WicrgbaVQjA o15GAknCfIOAvkcIryfA4N3BqrlyIvNUXbSbOXwLnLXglzYh+UFbvdD04WfnZ7qttufq aPLA8bibdVv/vpVcASfhhhAynpuCrJLN/Y7oQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=dq/7849gDX+0ySMh2NKeki4IKSTMdZkd94H6sy4OGfM=; b=d0hy+NiOnKv1vtlrrPQtfjbwopufDhphYMPEToxSFFdZW+dtMAPrniLH7KQrIjyPA2 K8iJ5y+PzdjBHcsr1Us815rvlJz8wSG3RG8q+zxXdC3PGg8k9qKCIOPxFYnd5cR1QCKd QPiCXAR8LlbICmeAqcNu6H+1OtjvDmFxhfm+ryvWTzddvz03m38AS5CzgwHmb/ClN+gk 4Et/CNsfAtbySkoq5c+IDU2PCUKNIKcREcaSfA+64BwOdZumEXZ160Wi0TFvkKO9HxYy nPjuRHLpn0u4ztIXSYT880CRwgCWWskeUTux2eK2lquFgenl7PiGY2UEC9yIlVYU3u01 Fccw== X-Gm-Message-State: AOAM5338c4mGIZf7RMqnZ+Mp2YpuhXQW0fckgXiIpGxIEiyLzmS7GPme nKRgLcOJHW6D92jqR/ZpLKGGYRoWWNHh7ZbQhcIEUBqHH6Zsow== X-Google-Smtp-Source: ABdhPJxPOaCaahOQSpR4cUQvezSfWSZW+v/y5+c3CkGdr6YxitOa46RmdNvyNlWb7L4jZU8Vlmqil/p0wObf/eRLnmw= X-Received: by 2002:ac2:4d47:: with SMTP id 7mr2980969lfp.58.1612395990958; Wed, 03 Feb 2021 15:46:30 -0800 (PST) MIME-Version: 1.0 References: <202009202026.08KKQ2x6137303@tahoe.cs.dartmouth.edu> <20210202234703.GH4227@mcvoy.com> <20210203001900.GI4227@mcvoy.com> In-Reply-To: From: Tom Lyon Date: Wed, 3 Feb 2021 15:46:20 -0800 Message-ID: To: Dave Horsfall Content-Type: multipart/alternative; boundary="000000000000476efd05ba773271" Subject: Re: [TUHS] reviving a bit of WWB X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Eunuchs Hysterical Society Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --000000000000476efd05ba773271 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable System/360s, or at least 370s, could do ASCII perfectly well. When we started UNIX on VM/370, it was clear to us that we wanted to run with ASCII. But some otherwise intelligent people told us that it *just couldn't be done* - the instructions depended on EBCDIC. But I think there was only 1 machine instruction with any hint of EBCDIC - and it was an instruction that no-one could imagine being used by a compiler, Of course, plenty of EBCDIC/ASCII conversions went on in drivers, etc, but that was easy. On Wed, Feb 3, 2021 at 12:09 PM Dave Horsfall wrote: > On Wed, 3 Feb 2021, Peter Jeremy wrote: > > > I'm not sure that 16 (or any other 2^n) bits is that obvious up front. > > Does anyone know why the computer industry wound up standardising on > > 8-bit bytes? > > Best reason I can think of is System/360 with 8-bit EBCDIC (Ugh! Who sai= d > that "J" should follow "I"?). I'm told that you could coerce it into > using ASCII, although I've never seen it. > > > Scientific computers were word-based and the number of bits in a word i= s > > more driven by the desired float range/precision. Commercial computers > > needed to support BCD numbers and typically 6-bit characters. ASCII > > (when it turned up) was 7 bits and so 8-bit characters wasted =E2=85=9B= of the > > storage. Minis tended to have shorter word sizes to minimise the amoun= t > > of hardware. > > Why would you want to have a 7-bit symbol? Powers of two seem to be > natural on a binary machine (although there is a running joke that CDC > boxes has 7-1/2 bit bytes... > > I guess the real question is why did we move to binary machines at all; > were there ever any ternary machines? > > -- Dave --=20 - Tom --000000000000476efd05ba773271 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Sys= tem/360s, or at least 370s, could do ASCII perfectly well.

When we started UNIX on VM/370, it was c= lear to us that we wanted to run with ASCII.=C2=A0 But some otherwise intel= ligent people told us that it *just couldn't be done* - the instruction= s depended on EBCDIC.
But I think there was only 1 machine instruction with any hint of EB= CDIC - and it was an instruction that no-one could imagine being used by a = compiler,

<= /div>
Of course, plen= ty of EBCDIC/ASCII conversions went on in drivers, etc, but that was easy.<= /div>

On Wed, Feb 3, 2021 at 12:09 PM Dave Horsfall <dave@horsfall.org> wrote:
On Wed, 3 Feb 2021, Peter Jeremy wrote:
> I'm not sure that 16 (or any other 2^n) bits is that obvious up fr= ont.
> Does anyone know why the computer industry wound up standardising on <= br> > 8-bit bytes?

Best reason I can think of is System/360 with 8-bit EBCDIC (Ugh!=C2=A0 Who = said
that "J" should follow "I"?).=C2=A0 I'm told that y= ou could coerce it into
using ASCII, although I've never seen it.

> Scientific computers were word-based and the number of bits in a word = is
> more driven by the desired float range/precision.=C2=A0 Commercial com= puters
> needed to support BCD numbers and typically 6-bit characters. ASCII > (when it turned up) was 7 bits and so 8-bit characters wasted =E2=85= =9B of the
> storage.=C2=A0 Minis tended to have shorter word sizes to minimise the= amount
> of hardware.

Why would you want to have a 7-bit symbol?=C2=A0 Powers of two seem to be <= br> natural on a binary machine (although there is a running joke that CDC
boxes has 7-1/2 bit bytes...

I guess the real question is why did we move to binary machines at all; were there ever any ternary machines?

-- Dave


--
- Tom
--000000000000476efd05ba773271--