Re: 64-bit bytes

From	Richard Heathfield <invalid@see.sig.invalid>
Organization	Go, ion artisan!
Subject	Re: 64-bit bytes
Newsgroups	comp.programming
References	(3 earlier) <07379e64-43df-4e01-9506-fee7d5f56c80@googlegroups.com> <GCEsw.973563$CW3.557830@fx07.am4> <98fc37e8-b786-4f52-8524-6d692c35f916@googlegroups.com> <ckMsw.1258654$u67.1004769@fx08.am4> <374f87c5-3ba9-48c3-8445-8ba4ab6af507@googlegroups.com>
Message-ID	<fcRsw.841985$kK3.398507@fx10.am4> (permalink)
Date	2015-01-12 14:51 +0000

Show all headers | View raw

robin.vowels@gmail.com wrote:

> On Monday, January 12, 2015 at 8:19:07 PM UTC+11, Richard Heathfield
> wrote:
>> r.nospam@gmail.com wrote:
>> 
>> > On Monday, January 12, 2015 at 11:32:42 AM UTC+11, Richard Heathfield
>> > wrote:
>> >> r.nospam.vowels@gmail.com wrote:
>> >> 
>> >> <snip>
>> >>  
>> >> > A byte is a fixed-length field of 8 bits.
>> >> 
>> >> ...except when it isn't. For example, some embedded systems
>> >> ("freestanding implementations") use 32-bit bytes. At least one of the
>> >> Analog SHARC chips uses 32-bit bytes.
>> > 
>> > They are more appropriately called "words".
>> 
>> So what would you call the smallest addressable unit of memory, then?
>> That's what "byte" is supposed to mean, after all.
> 
> No it's not.  There are machines where the smallest addressable unit of
> memory is the bit.

On such machines, bytes are 1 bit wide. (And yes, there are such machines. I 
designed a virtual machine with 1-bit bytes. I wrote four programs for it, 
three of which were rather dull.

> 
>> So if the smallest addressable
>> unit in a system is 12 bits, presumably a byte is 12 bits wide on that
>> system.
> 
> That would be a word.

Unless you work for MS.

> 
>> (There was a Cray, I forget which, with actual genuine 64-bit bytes,
> 
> They were 64-bit words.

You're just moving the problem on.

> Most of the early machines had words, of length 24 bits, 32, 36, 60 bits,
> etc etc.

And some had 9-bit bytes. Some even had 6-bit bytes.

<snip>

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within

Thread

64-bit bytes fir <profesor.fir@gmail.com> - 2015-01-05 01:38 -0800
  Re: 64-bit bytes robin.vowels@gmail.com - 2015-01-08 00:46 -0800
    Re: 64-bit bytes fir <profesor.fir@gmail.com> - 2015-01-08 00:53 -0800
      Re: 64-bit bytes robin.vowels@gmail.com - 2015-01-11 15:46 -0800
        Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 00:32 +0000
          Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 01:35 +0000
            Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 09:07 +0000
              Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 11:43 +0000
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 11:59 +0000
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 12:21 +0000
                Re: 64-bit bytes Mark Carroll <mtbc@bcs.org> - 2015-01-12 12:36 +0000
                Re: 64-bit bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-12 14:15 +0000
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 14:34 +0000
                Re: 64-bit bytes "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-01-12 16:35 +0100
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 17:42 +0000
                Re: 64-bit bytes "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-01-12 19:11 +0100
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 19:18 +0000
                Re: 64-bit bytes "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-01-12 21:34 +0100
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 22:01 +0000
                Re: 64-bit bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-13 00:51 +0000
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 13:18 +0000
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 14:16 +0000
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 14:48 +0000
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-12 15:05 +0000
                Re: 64-bit bytes Robert Wessel <robertwessel2@yahoo.com> - 2015-01-12 15:43 -0600
              Re: 64-bit bytes Kaz Kylheku <kaz@kylheku.com> - 2015-01-12 21:05 +0000
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 22:12 +0000
            Re: 64-bit bytes "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-01-12 10:12 +0100
          Re: 64-bit bytes robin.vowels@gmail.com - 2015-01-11 20:56 -0800
            Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 09:19 +0000
              Re: 64-bit bytes robin.vowels@gmail.com - 2015-01-12 06:22 -0800
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-12 14:51 +0000
                Re: 64-bit bytes robin.vowels@gmail.com - 2015-01-12 15:46 -0800
                Re: 64-bit bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-13 01:16 +0000
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-13 01:53 +0000
                Re: 64-bit bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-13 13:28 +0000
                Re: 64-bit bytes Richard Heathfield <invalid@see.sig.invalid> - 2015-01-13 13:57 +0000
                Re: 64-bit bytes "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-01-13 15:32 +0100
                Re: 64-bit bytes fir <profesor.fir@gmail.com> - 2015-01-13 06:33 -0800
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-13 16:41 +0000
                Re: 64-bit bytes fir <profesor.fir@gmail.com> - 2015-01-13 15:25 -0800
                Re: 64-bit bytes BartC <bc@freeuk.com> - 2015-01-13 23:49 +0000
                Re: 64-bit bytes fir <profesor.fir@gmail.com> - 2015-01-13 23:57 -0800

csiph-web