Can anyone explain what a gas neon diode is?

Post by **lynda** » Tue Jan 22, 2008 9:38 pm

Help! I have a very off topic question... I have an interview on Friday for a brilliant job to conserve ERNIE the original premium bond computer. I've been doing a bit of research online about it, and apparently it generated random numbers using a gas neon diode. Has anyone got any ideas about what that is and how it works - in simple terms please!

Thank you!

Post by **bmcecosse** » Tue Jan 22, 2008 9:45 pm

Diode is a device that only lets current flow in one direction. One way valve! Gas neon suggests glowing. Can't see it doing any counting on it's own - maybe they are the visual display of the numbers - I seem to remember ancient film of little circles of light going round and round ?

Post by **Orkney** » Tue Jan 22, 2008 9:46 pm

Sorry no, but whilst your there can you give the bugger a kick from me on account of he seems to have forgoten all about my £5 of bonds from since i was an infant !!!

Post by **lynda** » Tue Jan 22, 2008 9:59 pm

The wikipedia page describes it slightly differently as "generating its bond numbers based on the signal noise created by a bank of neon tubes".

I had £25 worth of premium bonds from 1984, just given up and cashed them in

Sorry Orkney, I probably shouldn't kick the machines with the interviewers present if I want any chance of getting the job....

Post by **bmcecosse** » Tue Jan 22, 2008 10:01 pm

Well found - perhaps that's where the 'randomness' creeps in. Good luck with the job. And do come back and tell us what they really are !

Post by **alex_holden** » Tue Jan 22, 2008 10:07 pm

Woah, that sounds fun. I hope you get the job.

A biassed diode can be used as a source of entropy in a RNG through the avalanche effect. Basically if you bias it until it's about to break down, you can't predict exactly when it's going to do so.

Not heard of a neon diode. It may actually use a neon lamp - they have interesting electrical properties and were used in some early digital computers (not just as display devices).

Post by **alex_holden** » Tue Jan 22, 2008 10:10 pm

bmcecosse wrote:I seem to remember ancient film of little circles of light going round and round ?

That sounds like a dekatron - a neon tube that acts as a digital counter. http://en.wikipedia.org/wiki/Dekatron

Post by **bigginger** » Tue Jan 22, 2008 10:14 pm

From what I remember, the Ernie that they showed on TV looked very much like a display prop, not a genuine electronic device
a

Post by **Orkney** » Tue Jan 22, 2008 10:18 pm

Err whats that in English then Alex ?

Post by **alex_holden** » Tue Jan 22, 2008 10:20 pm

bigginger wrote:From what I remember, the Ernie that they showed on TV looked very much like a display prop, not a genuine electronic device
a

I wouldn't be surprised if there was a small metal box inside doing the real work!

Post by **alex_holden** » Tue Jan 22, 2008 10:22 pm

Orkney wrote:Err whats that in English then Alex ?

Well there's these little glass tubes with pixies inside. You give them an electric shock, and if they go "eek" that's a number 0, if they go "argh" that's a number 1.

Post by **Orkney** » Tue Jan 22, 2008 10:23 pm

I wouldn't be surprised if there was a small metal box inside doing the real work!

or a Gerbil with some buttons with peanuts stuck to them

Post by **Peetee** » Wed Jan 23, 2008 7:13 am

I probably shouldn't kick the machines with the interviewers present if I want any chance of getting the job

Maybe that has the same effect as hitting a Minor fuel pump with a hammer.

Good luck.

Post by **8009STEVE** » Wed Jan 23, 2008 10:15 am

if they go "eek" that's a number 0, if they go "argh" that's a number 1.

There are 10 types of people who can read binary. Those that can and those that cant.

Post by **bigginger** » Wed Jan 23, 2008 2:02 pm

Good to see that joke again on here.

It never dulls
a

Post by **Kevin** » Wed Jan 23, 2008 5:48 pm

Good to see that joke again on here. It never dulls
a

Thank goodness you said that Andrew as it difficult to understand this new teknologey stuff

at the best of times.

Post by **bmcecosse** » Thu Jan 24, 2008 1:24 pm

I doubt it would be a 'small metal box' - more likely a huge shed full of equipment doing the work.

Post by **alex_holden** » Thu Jan 24, 2008 1:30 pm

The actual secure random number generator could be very small indeed. Back then it would probably have been linked to an ordinary mainframe computer that did the administrative stuff like figuring out who had won.

Post by **lynda** » Sat Jan 26, 2008 2:43 pm

I've made it back from the depths of Wiltshire! About 550 miles in two days in my Moggy with no problems

I think the interview went well, just have to wait until next week to find out...

I don't have an answer about the diode thing, they didn't ask me to explain so I decided not to demonstrate total ignorance of how it worked by asking them - that can wait until I get the job (if I get it!). Definitely no gerbils though (unless they were hiding).

Post by **lynda** » Sat Jan 26, 2008 2:46 pm

alex_holden wrote:The actual secure random number generator could be very small indeed. Back then it would probably have been linked to an ordinary mainframe computer that did the administrative stuff like figuring out who had won.

It seemed to all be one machine - and a very big one too, taller than me and around 7 foot long, 2 foot wide.