Neon bulb logic elements link? - test-drb@ccmp.vtda.org

25 May 2005

...

Subject: Re: Neon bulb logic elements link?
   From: "Dwight K. Elvey" <dwight.elvey at amd.com>
   Date: Wed, 25 May 2005 16:05:54 -0700 (PDT)
     To: cctalk at classiccmp.org

 From: "Eric Smith" <eric at
brouhaha.com>

I wrote:
  You turn on a particular tube by dropping the X
line to 0V and raising
 the Y line to +105V.  The selected tube sees 105V, while the other tubes
 in the same row and column see 97.5V. 
Tom wrote:
  I think your idea is generally right, but this
detail seems wrong:
 when X goes from +7.5V to 0V, the entire line will see 105V,
 striking the entire line. 
Nope.

                  7.5V            0V

                   X0             X1
                    |              |
                    |              |
 97.5V  Y0 --------90V-----------97.5V
                    |              |
                    |              |
105.0V  Y1 --------97.5V----------105V

Locations (0,0), (1,0), and (1,0) are all still below the strike
voltage.

Hi
 When building neon logic, it might be better to consider
using capacitive coupling to connect up your logic.
Otherwise you may find that you'll have a significant
level shifting problem.
 Just a thought
Dwight

The general design rules were pulse logic based so capacitive coupling 
was the norm and diodes were not uncommon.

I've done simple binary counters and shift registers with NE2s and
it's fun and fairly tolerent.  Somewhere I've seen a complete schematic
for a 3T (Tic Tac Toe) player that used Neon lamps and 2D21 thyratrons.

Allison