In a message dated 2/28/2001 7:32:36 PM Eastern Standard Time,
barry@ZMICRO.COM writes:

<< >        Speaking of old technology, anyone remember the (RCA, I think)
Numitron
 >display? It was a seven segment display using incandescent filaments. You
 >could use them just like an LED seven segment, but could not multiplex
 >them without adding a bunch of diodes.
 >
 >Harold

 A friend of mine built his first project, a digital clock, using
 the Numitron tubes.  A counter, decoder, driver for each digit.

 Actually, it was his second project.  His first attempt involved
 building all the logic out of TRANSISTORS, then he got turned
 onto TTL and scrapped all that.  I still have one of the discrete
 counter boards and used to use it as a prop when giving basic
 digital logic presentations.  (As in, "This chip here does what
 this board over here did.")

 This was 1972.  After I met him, he turned me on to TTL stuff.
 My first project like this was almost a Nixie clock.  The
 company (B&F) that I got the kit from took their clock and
 added a timebase board, and voila...frequency counter.
 Unfortunately the 180V for the displays came in contact
 with the 5V for the logic...decimated the poor thing.  I
 rebuilt it and learned ALL about logic and troubleshooting.

 Barry
  >>
This is a great chuckle for me.  I graduated EE, 1960, and I very well
remember these evolutions.  Thanks for the memory.

I wonder if one can still buy Nixie tubes.  They were cool.

Max

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