KDF9 Core Storage

This is the core storage module from the English Electric KDF9
computer installed at Newcastle University in 1963.
It is 585mm high, 443mm depth and 342mm width.
It weighs 14 Kg and has a storage capacity of 100,000 bits,
in modern day terms that is 24KBytes.
The black/yellow wires with printed circuit brown cards on the end
was the way the module was connected to the circuitry that controlled it.
There is no computer logic in this module,
just core storage and connectors, not a transistor.

This is looking down on the core storage planes.
You can get the scale of it from my feet!

Here is a close-up of the core storage plane.
It contains 4 core mats in each plane,
each mat is 40 by 25 cores measuring 4cm by 2.5cm.
So the whole core plane contains 4000 bits of memory.
There are 4 wires through each core: 50 X horizontal wires thread the 50 rows;
and 80 Y vertical wires threading all the 80 columns;
another single wire threads vertically all the cores;
the fourth wire threads all the rows.

There are 25 core planes, shown here,
making the total number of cores 100,000.
That is in modern day terms 24KBytes.
The core plane areal density is 37 cores per square centimetre.
Remember that when you look at other later examples of core storage.

This is a photograph of a photograph that includes a photograph.
It shows a KDF9 computer in the main photograph
with two banks of metal cabinets framing the computer operator
with two magnetic tape drives beyond and a paper tape punch to her left.
The photograph within the photograph shows 3 magnetic tape drives,
2 paper tape readers, the computer operator and the paper tape punch.