Old computer tech: delay-line memory

erco

Hard to believe this actually worked. Anybody remember this old tech? Twisting nickel strands in a long coil. I'm still not sure how it seperates the "bits" on readback. The neat old guy in the video (sounds likee EEVblog's Dave's Dad) says it predates him, so this really is old school. BTW that guy also has a Youtube channel with some other interesting stuff.

Edit: @Heater & Loopy, please settle a bet. Is it really true that Linux is still based on this technology?

Heater.

Even pre-dates my time. Back in the day they tried acoustic delay lines with wires. More successfully with tubes full of mercury. Somewhere on youtube is a great video describing Colossus rebuild at Bletchley Park and it's mercury delay line memory. Sorry I can't find it just now.

Separating the bits on read back is much the same as problem as our old acoustic modems back in the day, or saving digital data to cassette tape.

Here is a young guy describing how to send data over a wireless audio connection. Make a long enough audio connection and loop it around and you have a memory device.

xanadu

XJet is a great channel. Didn't expect to see anything like this, very interesting.

When a pulse of current is fed into the transmitter coil, the build up and decay of magnetic fiux in that part of the tube within the coil causes a longitudinal contraction in physical dimension in accordance with the Joule magnetostrictive elfect. This elastic disturbance is propagated along the tube at the velocity of sound in nickel. (At average room temperature 4900 meters per second or 5.27 microseconds per inch.)

https://www.google.com/patents/US2846654

Mike Green

When I was a student at Case Inst. of Tech. they had a Univac I with mercury delay line memories. There were these tanks with transmitter/receiver strips (studded with vacuum tubes) around the tanks. Pulse streams went from one strip to the next through the tank to provide enough delay time for that tank's memory. Eventually the mercury was replaced with some less-toxic solution.

KMyers

Before my day also but I remember these delay lines used in scopes and a spectrum analyzers for video and LOW frequency testing.

Seairth

Heater. wrote: »

Here is a young guy describing how to send data over a wireless audio connection. Make a long enough audio connection and loop it around and you have a memory device.

lol. Isn't this basically what Scotty did to himself (with a transporter) on STNG (episode "Relics")? Coincidence? I think not!

Heater.

Seairth,

I think you are on to something...

We can pump data all the way around the world and back again in 133ms via fiber optic cable.

Soon the bandwidth of fibre will be 255tbps http://www.extremetech.com/extreme/192929-255tbps-worlds-fastest-network-could-carry-all-the-internet-traffic-single-fiber

So I reckon we can store 34 Tera bytes of data on a fibre in flight around the planet.

Given a bunch of fibres recycling the data in loops like that we won't need to store anything locally on hard drives or SSD anymore.

One would never have to access a web site, just wait for the data you want to come around and read it! Average 66ms access time.

Leon

When I was a student apprentice at English Electric, Kidsgrove, in 1963, they still had an operational DEUCE computer that used valves and mercury delay line storage. This is one of the assemblies:

https://uk.images.search.yahoo.com/search/images;_ylt=A9mSs2Kv1tRVsSQA5rdLBQx.;_ylu=X3oDMTByZmVxM3N0BGNvbG8DaXIyBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=English+Electric+Deuce&fr=mcafee#id=64&iurl=http://ed-thelen.org/comp-hist/DEUCE_mushroom-.jpg&action=click

It contains several delay lines.