27 Feb
2003
27 Feb
'03
4:13 p.m.
Robert Nansel wrote:
I came across reference to a file, LAMP.ZIP, you
posted briefly for the
Classic Computer list back in '99. Would it be possible for me to get this
file? I'm fascinated by the idea of making counters, logic gates, and
memory elements using neon lamps, but repeated google searches reveal very,
very little hard information (other than there were such circuits).
Yes you can. I had a old electronic magazine* around years 1960 to 1962
that had such a beast.Alas the box I had my old magizines in got wet. :(
They switch the same way as a tunnel diode switches, using negitive
resistance and brute force. Inputs are capacitor coupled if I remember
right with diode logic for gating logic.
Also, I've read a few pages on early calculators
(such as the Anita) using
something similar to neon lamps for logic gates and ring counters, though
the pictures lead me to believe they are actually 4-lead gas triodes or
thyratrons of some kind. Do you know what these beaties actually were?
They had decade counters but I don't have any links handy. Nixie tubes
are nice too.
Finally, I've repeatedly run across mention that
neon device switching is
slow, but how slow are they?
I think 1000 cycles per second do to RC time constants. Any how
don't use neon bulbs with a built in dropping resistor. Paint
the bulb black to prevent light from triggering the devices.
Cosmic rays may do that too.
You assistance is appreciated!
Ben.
* those days magazines had few ads and profesional
content.