It was the electron flow cabal.  Their sworn purpose was to abolish
the conventional flow model and get everyone to follow the 'real' way
electrons move.  They secretly infiltrated the various committees so
they could push their model, which included using negative voltages
all over the POTS and in any other area they could push their agenda.

It would have worked, too, if it weren't for those meddling kids.

/tongue in cheek

-Adam

On Sat, Nov 14, 2009 at 5:55 AM, Wouter van Ooijen <wouter@voti.nl> wrote:
> In a lesson I want to explain asynch serial data format and RS232 signal
> levels.
>
> AFAIK the RS232 signal levels predate the 5V TTL levels (correct)?
>
> The TTL-RS232 level converters/shifters are all inverting. Does anyone
> know why? Because inverting drivers are slightly easier to build? Or
> were the asynch-on-TTL levels chosen first, and as a consequence the
> drivers had to be inverters?
>
> --
>
> Wouter van Ooijen
>
> -- -------------------------------------------
> Van Ooijen Technische Informatica: www.voti.nl
> consultancy, development, PICmicro products
> docent Hogeschool van Utrecht: www.voti.nl/hvu
>
> --
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