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Looking for (really) old construction article

Benjy Boy

Sep 30, 2014
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Sep 30, 2014
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I am looking for a computer construction article from my youth. The
project contained several flip-flops to form a counter. Each
flip-flop was on a single board and constructed from two TO-3 power
transistors, one of which drove an incandescent lamp. The counter was
driven by a rotary phone dial. The circuit added numbers dialed
on the rotary dial. To subtract, you had to do ten's complement or
some such. The output was read in binary from the incandescent lights.

I thought the article was in Popular Electronics from the mid-1950's or
early 1960's, but some time with a microfiche machine hasn't turned
up the article. I did find a similar article in the November 1966
Electronics Illustrated (http://www.dos4ever.com/ring/ELIL.pdf);
however, this circuit uses neon blubs to form the counter.

A similar device is shown in a picture at The Obsolete Computer Museum
site on top of a TRS-80: http://www.radar58.com/Computer/pcs.jpg

I'm interested in the article for its historical significance since
it is one of the earliest computer projects I know of. Any help
locating the article would be appreciated.
 

KMoffett

Jan 21, 2009
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Jan 21, 2009
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Wow. I remember that! Lots of 2N3055s and a rotary telephone dial as an input number/count generator. But, all my Poptronics magazines went long ago.

Ken
 

shrtrnd

Jan 15, 2010
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Jan 15, 2010
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3,876
Maybe Popular Electronics has an archive. Did you contact them to ask?
 

Benjy Boy

Sep 30, 2014
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Sep 30, 2014
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I believe that the transistors were indeed 2N3055's. I had forgotten that.

I've looked on the web for Popular Electronic archives. Also, I looked at the issues I could find on microfiche. From the Wikipedia article on Popular Electronics, it seems the publisher hasn't been in business for awhile.
 

Benjy Boy

Sep 30, 2014
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Sep 30, 2014
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Ken, Thanks for the links. That's really great! I had missed that site. It appears they have all the issues missing from the collection I looked at. I'm not sure the article I'm looking for is in PE, but it probably was. So now I can be sure. Benjy
 

KMoffett

Jan 21, 2009
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Jan 21, 2009
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Yeah! OK, I was wrong about Popular Electronics and the 2N3055. But it was a TO-3 case. :)

Ken
 
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