Re: Getting started with AVR and C

From	glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups	comp.arch.embedded, comp.lang.c
Subject	Re: Getting started with AVR and C
Date	2012-11-29 21:23 +0000
Organization	Aioe.org NNTP Server
Message-ID	<k98jou$n5a$1@speranza.aioe.org> (permalink)
References	(6 earlier) <0.b3ca9d18d0528a0b5ff8.20121129011842GMT.871ufdtde5.fsf@bsb.me.uk> <JaGdnZ29kdH_XivNnZ2dnUVZ_oOdnZ2d@web-ster.com> <k97ulf$jpg$3@reader1.panix.com> <k980sv$sh4$1@dont-email.me> <diefb8p226eou89jtfpg1ddfflsubt9sq0@4ax.com>

Cross-posted to 2 groups.

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In comp.lang.c Jon Kirwan <jonk@infinitefactors.org> wrote:
> On Thu, 29 Nov 2012 11:01:34 -0500, James Kuyper
> <jameskuyper@verizon.net> wrote:

>><snip>
>>Claims have frequently been made on
>>comp.lang.c that, while the C standard allows CHAR_BIT != 8, the

As I remember the stories, the CRAY-1 had 64 bit char.

>>existence of such implementations is a myth. I'm glad to have a specific
>>counter example to cite.
>><snip>

> I believe that C was implemented on the PDP-10. I didn't use
> it when I was programming the PDP-10 (I used assembly, then,
> and some other languages... but not C, until I worked on Unix
> v6 in '78.) But that was a 36-bit machine. And ASCII was
> packed into 7 bits so that 5 chars fit in a word. No one used
> 8, so far as I recall. That was the standard method. So I'm
> curious now what the C implementation did.

Yes the TOPS-10 file format stores ASCII as 5 characters
to the word, but C can't do that. In a discussion some time
ago about actual implementations, 9 and 18 bit char were
discussed. The PDP-10 has instructions for operating on
halfwords, which could be used, possibly with execute (XCT)
to select the appropriate instruction, or for loops an 
unrolled loop. Or 9 bit chars using the byte instructions.

> Of course, all that is prior to any standard. But it might be
> another case to discuss, anyway.

I keep wondering about a C compiler for the 7090, one of the
last sign magnitude machines, and also 36 bits. It was usual
to store six 6 bit BCDIC (more often called just BCD) characters
per word. Also, 6 bit characters on 7  track magnetic tape.

The card reader on the 704, and I will guess also the 7090, 
reads one card row into two 36 bit words, ignoring the last
eight columns. Software had to convert that into 12 
characters in two words.

-- glen

Thread

Getting started with AVR and C Robert Roland <fake@ddress.no> - 2012-11-24 17:41 +0100
  Re: Getting started with AVR and C hamilton <hamilton@nothere.com> - 2012-11-24 09:55 -0700
    Re: Getting started with AVR and C David Brown <david.brown@removethis.hesbynett.no> - 2012-11-25 10:39 +0100
  Re: Getting started with AVR and C Rene <a@b.c> - 2012-11-24 18:03 +0100
    Re: Getting started with AVR and C Rene <a@b.c> - 2012-12-10 13:21 +0100
      Re: Getting started with AVR and C Christopher Head <chead@is.invalid> - 2012-12-10 18:33 -0800
        Re: Getting started with AVR and C Rene <a@b.c> - 2012-12-11 12:34 +0100
  Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.please> - 2012-11-24 12:44 -0600
  Re: Getting started with AVR and C me@linnix.info-for.us - 2012-11-24 11:12 -0800
  Re: Getting started with AVR and C mike <ham789@netzero.net> - 2012-11-24 11:28 -0800
    Re: Getting started with AVR and C me@linnix.info-for.us - 2012-11-24 11:42 -0800
      Re: Getting started with AVR and C mike <ham789@netzero.net> - 2012-11-25 07:01 -0800
    Re: Getting started with AVR and C David Brown <david.brown@removethis.hesbynett.no> - 2012-11-25 20:14 +0100
  Re: Getting started with AVR and C Ivan Shmakov <oneingray@gmail.com> - 2012-11-25 03:18 +0700
  Re: Getting started with AVR and C Ivan Shmakov <oneingray@gmail.com> - 2012-11-25 04:18 +0700
    Re: Getting started with AVR and C Richard Damon <news.x.richarddamon@xoxy.net> - 2012-11-24 17:09 -0500
    Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-24 22:12 +0000
      Re: Getting started with AVR and C Dave Nadler <drn@nadler.com> - 2012-11-24 21:01 -0800
        statement / expression contexts in C Ivan Shmakov <oneingray@gmail.com> - 2012-11-28 12:54 +0700
      Re: Getting started with AVR and C Ivan Shmakov <oneingray@gmail.com> - 2012-11-28 13:37 +0700
        Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-28 14:49 +0000
        Re: Getting started with AVR and C Frank Miles <fpm@u.washington.edu> - 2012-11-28 17:53 +0000
          Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-28 18:05 +0000
            Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 12:56 -0600
              Re: Getting started with AVR and C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-11-28 21:45 +0000
                Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 15:55 -0600
                Re: Getting started with AVR and C David Brown <david.brown@removethis.hesbynett.no> - 2012-11-29 01:35 +0100
                Re: Getting started with AVR and C Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-11-29 01:47 +0100
                Re: Getting started with AVR and C David Brown <david@westcontrol.removethisbit.com> - 2012-11-29 09:24 +0100
                Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-29 01:18 +0000
                Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 20:07 -0600
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 15:23 +0000
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 11:01 -0500
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 19:19 +0000
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 14:32 -0500
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-11-29 11:44 -0800
                Re: Getting started with AVR and C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-11-29 21:23 +0000
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-11-29 18:15 -0800
                Re: Getting started with AVR and C me@linnix.info-for.us - 2012-11-30 09:26 -0800
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-11-30 13:22 -0800
                Re: Getting started with AVR and C me@linnix.info-for.us - 2012-11-30 14:10 -0800
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-11-30 15:16 -0800
                Re: Getting started with AVR and C Mel Wilson <mwilson@the-wire.com> - 2012-11-30 17:36 -0500
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-11-30 15:18 -0800
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-01 10:08 +0200
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-01 00:45 -0800
                Re: Getting started with AVR and C Ed Beroset <beroset@mindspring.com> - 2012-12-01 08:00 -0500
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-01 13:22 -0800
                Re: Getting started with AVR and C Mark Borgerson <mborgerson@comcast.net> - 2012-12-01 17:33 -0800
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-01 17:43 -0800
                Re: Getting started with AVR and C Mark Borgerson <mborgerson@comcast.net> - 2012-12-02 14:13 -0800
                Re: Getting started with AVR and C Walter Banks <walter@bytecraft.com> - 2012-12-04 20:34 -0500
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-04 18:25 -0800
                Re: Getting started with AVR and C Walter Banks <walter@bytecraft.com> - 2012-12-05 07:55 -0500
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 12:11 -0800
                Re: Getting started with AVR and C Mark Borgerson <mborgerson@comcast.net> - 2012-12-05 07:52 -0800
                Re: Getting started with AVR and C Walter Banks <walter@bytecraft.com> - 2012-12-05 11:02 -0500
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-05 21:28 +0200
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 12:21 -0800
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-05 23:05 +0200
                Re: Getting started with AVR and C Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2012-12-05 23:22 +0200
                Re: Getting started with AVR and C Niklas Holsti <niklas.holsti@tidorum.invalid> - 2012-12-06 00:00 +0200
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 12:17 -0800
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-05 23:10 +0200
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 15:25 -0800
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-06 07:15 +0200
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 21:52 -0800
                Re: Getting started with AVR and C Lanarcam <lanarcam1@yahoo.fr> - 2012-12-06 20:59 +0100
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-06 12:38 -0800
                Re: Getting started with AVR and C George Neuner <gneuner2@comcast.net> - 2012-12-06 20:39 -0500
                Re: Getting started with AVR and C Walter Banks <walter@bytecraft.com> - 2012-12-06 22:31 -0500
                Re: Getting started with AVR and C Mel Wilson <mwilson@the-wire.com> - 2012-12-05 16:32 -0500
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 15:25 -0800
                Re: Getting started with AVR and C dp <dp@tgi-sci.com> - 2012-12-05 17:04 -0800
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-12-05 22:01 -0800
                Re: Getting started with AVR and C Ian Malcolm <See.My.Sig.for.email@totally.invalid> - 2012-12-06 14:05 +0000
                Re: Getting started with AVR and C dp <dp@tgi-sci.com> - 2012-12-06 10:28 -0800
                Re: Getting started with AVR and C Mark Borgerson <mborgerson@comcast.net> - 2012-12-06 16:58 -0800
                Re: Getting started with AVR and C Mark Borgerson <mborgerson@comcast.net> - 2012-12-06 07:34 -0800
                Re: Getting started with AVR and C Walter Banks <walter@bytecraft.com> - 2012-12-06 10:55 -0500
                Re: Getting started with AVR and C Rich Webb <bbew.ar@mapson.nozirev.ten> - 2012-12-06 11:11 -0500
                Re: Getting started with AVR and C Rocky <RobertGush@gmail.com> - 2012-12-06 21:38 -0800
                Re: Getting started with AVR and C dp <dp@tgi-sci.com> - 2012-12-07 03:49 -0800
                Re: Getting started with AVR and C Robert Wessel <robertwessel2@yahoo.com> - 2012-12-01 02:58 -0600
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-01 17:28 +0200
                Re: Getting started with AVR and C Robert Wessel <robertwessel2@yahoo.com> - 2012-12-01 11:55 -0600
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-11-29 22:17 +0200
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-11-29 12:36 -0800
                Re: Getting started with AVR and C Stephen Sprunk <stephen@sprunk.org> - 2012-11-29 16:22 -0600
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-11-29 18:36 -0800
                Re: Getting started with AVR and C "Boudewijn Dijkstra" <sp4mtr4p.boudewijn@indes.com> - 2012-12-11 10:53 +0100
                Re: Getting started with AVR and C John Devereux <john@devereux.me.uk> - 2012-12-11 14:53 +0000
                Unicode Ivan Shmakov <oneingray@gmail.com> - 2012-12-14 23:25 +0700
                Re: Getting started with AVR and C Richard Damon <news.x.richarddamon@xoxy.net> - 2012-12-15 14:30 -0500
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-12-15 12:24 -0800
                Re: Getting started with AVR and C Richard Damon <news.x.richarddamon@xoxy.net> - 2012-12-15 18:02 -0500
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-12-15 15:45 -0800
                Re: Getting started with AVR and C Richard Damon <news.x.richarddamon@xoxy.net> - 2012-12-16 22:55 -0500
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-12-16 23:20 -0800
                Re: Getting started with AVR and C Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-12-17 12:27 +0200
                Re: Getting started with AVR and C John Devereux <john@devereux.me.uk> - 2012-12-17 11:17 +0000
                Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-17 14:07 +0000
                Re: Getting started with AVR and C Nobody <nobody@nowhere.com> - 2012-12-16 03:28 +0000
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-12-16 10:40 +0200
                Re: Getting started with AVR and C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-11-29 02:31 +0000
                Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-29 03:36 +0000
                Re: Getting started with AVR and C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-11-29 03:55 +0000
                Re: Getting started with AVR and C Christopher Head <chead@is.invalid> - 2012-11-28 23:24 -0800
                Re: Getting started with AVR and C David Brown <david@westcontrol.removethisbit.com> - 2012-11-29 09:37 +0100
                Re: Getting started with AVR and C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-11-29 11:31 +0000
                Re: Getting started with AVR and C David Brown <david@westcontrol.removethisbit.com> - 2012-11-29 13:44 +0100
                Re: Getting started with AVR and C Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-11-29 13:22 +0100
                Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-29 13:32 +0000
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-11-29 11:28 -0800
                Re: Getting started with AVR and C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-29 13:20 +0000
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 09:07 -0500
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 09:17 -0500
                Re: Getting started with AVR and C pete <pfiland@mindspring.com> - 2012-11-29 18:25 -0500
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 22:46 -0500
                Re: Getting started with AVR and C lawrence.jones@siemens.com - 2012-11-30 11:47 -0500
                Re: Getting started with AVR and C Keith Thompson <kst-u@mib.org> - 2012-11-29 11:38 -0800
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 15:21 -0500
              Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-28 22:26 +0000
                Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 17:32 -0600
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-28 19:02 -0500
                Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 18:29 -0600
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-28 23:39 -0500
                Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.please> - 2012-11-29 00:59 -0600
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 07:57 -0500
                Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-29 13:02 -0600
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 15:19 +0000
                Re: Getting started with AVR and C Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-11-29 12:03 +0200
                Re: Getting started with AVR and C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-11-29 11:39 +0000
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-29 08:04 -0500
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 15:17 +0000
              Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 19:19 -0600
                Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-28 23:44 -0500
          Re: Getting started with AVR and C James Kuyper <jameskuyper@verizon.net> - 2012-11-28 13:15 -0500
            Re: Getting started with AVR and C Arlet Ottens <usenet+5@c-scape.nl> - 2012-11-28 19:17 +0100
              Re: Getting started with AVR and C Tim Wescott <tim@seemywebsite.com> - 2012-11-28 19:30 -0600
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 15:29 +0000
                Re: Getting started with AVR and C John Devereux <john@devereux.me.uk> - 2012-11-29 16:36 +0000
                Re: Getting started with AVR and C upsidedown@downunder.com - 2012-11-29 22:40 +0200
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-11-29 13:55 -0800
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 22:06 +0000
                Re: Getting started with AVR and C Jon Kirwan <jonk@infinitefactors.org> - 2012-11-29 14:22 -0800
                Re: Getting started with AVR and C Grant Edwards <invalid@invalid.invalid> - 2012-11-29 21:59 +0000
                Re: Getting started with AVR and C John Devereux <john@devereux.me.uk> - 2012-11-30 08:29 +0000
    Re: Getting started with AVR and C Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-11-25 05:41 -0800
    Re: Getting started with AVR and C Rosario1903 <Rosario@invalid.invalid> - 2012-11-27 10:21 +0100
  Re: Getting started with AVR and C dbr@kbrx.com - 2012-11-24 21:49 +0000
    Re: Getting started with AVR and C MK <mk@nospam.co.uk> - 2012-11-25 12:24 +0000
      Re: Getting started with AVR and C Ian Malcolm <See.My.Sig.for.email@totally.invalid> - 2012-11-26 00:08 +0000

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