11 Feb
2015
11 Feb
'15
7:11 a.m.
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
>
>