back to the AGC, was Re: TTL 7400's Available

[Chuck Guzis]

On 2 Jan 2007 at 22:18, Brent Hilpert wrote:

> Yes, I'm finding those references as well. Although it seems quite early for
> electroluminescent displays too, don't know of anything else that was using
> them at that time, esp. in 7-seg form.

I recall a Popular Science (IIRC) article of around that same time 
gushing about how EL was going to revolutionize the world and one of 
the applications shown was a large 7 segment display.   

Work with EL generated quite a bit of interest back in the 60's, 
including light amplification for radiography (make a sandwich of 
dots of EL cells with CdS photoresistors and apply an AC voltage.  
The dark cells will tend to stay dark, while those that fluoresce 
under bombardment will form a feedback loop.)  Reminds me of making a 
code practice oscillator by sandwiching a carbon mic with an 
earphone.  I don't know if the technology ever made it to prime time.

So that it used EL doesn't surprise me.  The only other alternatives 
(incandescent, plasma, mechanical) were probably too power-hungry 
and/or fragile.

Cheers,
Chuck