AVR-Chat

--- In AVR-Chat@yahoogroups.com, "Anurag Chugh" <lithiumhead@m...> 
wrote:

> I wrote to one of the authors of
> the digital design books we use
> as text in college on why 5v was
> choosen as logic one...

5 volts was not "chosen as logic one". You're confusing logic levels 
with the supply voltage of the logic circuits.

> this is what he has to say.. 
> PS please read the linked essay

> Or perhaps it's more like the reason
> that railroad tracks are separated
> by the width that they are
> (see www.naciente.com/essay94.htm).

This is pretty pathetic. If you read the essay, for heavens sake also 
read up on the railroad boom in the United States and the wide variety 
of gauges that were originally used for the different lines. The essay 
may be funny, but it does not accurately represent the facts.

Your author clearly doesn't know the answer to your question. If you're 
really interested, you should research RTL and DTL, which were wiped 
out by TTL and also ECL which was around at the time and still lives 
on. That shouldn't be to hard for a college student. First, get it 
clear in your mind whether you are interested in the supply voltage or 
logic levels.

Here's another gross simplification of reality: those that can do, 
those that can't teach, and those that can't teach write the text books.

Graham.