Re: Bit twiddling

On Sun, 5 Jun 2005 09:24:48 +0100, Chris Croughton
<chris@xxxxxxxxxxxx> wrote:

> On Sat, 04 Jun 2005 09:11:56 -0400, Joe Wright
<snip>
> > More interesting is a bit's value in time. Think of async serial bytes:
> > start bit, 8 data bits and stop bit. It is of crucial importance that we
> > know whether the bit after the start bit is the lsb or the msb of the
> > byte. I used to know. Really. :-)
>
> LSB first (see CCITT V.24) <g>. That one I /do/ remember, I was
> programming async serial comms for a long time...
>
I never saw the CCITT one, but once did the ANSI (X3) equivalent
(which I believe was also FIPSed back when those mattered). It was
rather amusing because it had all the structure of any X3 standard:
identification of sponsor and participants in development, rules for
applicability, name and address of the secretariat, etc., totalling
about a page, but the substantive content was one short sentence,
something like "The order of bit transmission of ASCII on a serial
interface shall be least to most significant."

- David.Thompson1 at worldnet.att.net
.