imitation game movie

[Dave G4UGM]

Delay Lines have been used as storage in a number of UK designed computers..

Whilst not "Ultra Fast" the Ferranti Pegasus used delay lines as main store. There is a (not very good) picture of the board here:-

http://www.ourcomputerheritage.org/F3%20Pegasus%20nickel%20delay%20line.htm

If I remember properly the Pegasus ran at 333Khz and was clocked off the drum, to ensure everything synced with the drum. Being a serial machine this was ideal storage...

The ESDAC at Cambridge used mercury delay lines which were faster but reputedly less reliable......

... more recently (but still a long time ago in Computing) Manchester Universities MU5 used a plated wire store system, which was "fast" 

http://www.cs.manchester.ac.uk/about-us/history/mu5/

and scroll down to "Instruction Accessing". I remember been shown this towards the end of MU5's life...

.. so we did develop fast, if not "ultra fast"  re-circulating memory....
.. its just it was more expensive than core and more expensive that DRAM...

Dave Wade
G4UGM





> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Mike Stein
> Sent: 11 February 2015 07:24
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: imitation game movie
> 
> > Would we have developed ultra-fast recirculating memory?
> 
> Now there's an idea (has it been tried?); the equivalent of an acoustic delay
> line memory using fiber optics...
> 
> m
> 
> ----- Original Message -----
> From: "Chuck Guzis" <cclist at sydex.com>
> To: <General at classiccmp.org>;
> "Discussion at classiccmp.org:On-Topic and Off-Topic
> Posts" <cctalk at classiccmp.org>
> Sent: Wednesday, February 11, 2015 1:38 AM
> Subject: Re: imitation game movie
> 
> 
> > On 02/10/2015 09:56 PM, Jon Elson wrote:
> >
> >> Oh, absolutely!  There was a lot of work on
> >> using ferrite rings as storage
> >> and logic elements at that time, but Forrester
> >> and Papian really
> >> extended what had been done before, and the
> >> coincident current
> >> scheme was really ELEGANT and made large arrays
> >> of fast memory
> >> practical.  The bigger you built the array, the
> >> more memory you got
> >> with small increments in the number of drivers.
> >
> > Didn't coincident-current relays come before
> > that (as used, for example, in telephone
> > switching equipment)?  So the basic idea was
> > there.
> >
> > I've always been fascinated by magnetic core
> > logic; both using "hard" magnetics (e.g. Univac
> > SS) and "soft" (e.g. Parametrons).  I wonder if
> > magnetic core for memory hadn't been developed,
> > would we have developed electrostatic or some
> > other technology to the same density?
> >
> > Would we have developed ultra-fast recirculating
> > memory?
> >
> > --Chuck
> >
> >