New Twist in Memory Devices
1958 Radio Electronics Article
another blast from the past, I just found an advertisement by Bell Telephone
Laboratories announcing "Twistor" memory in a 1958 edition of Radio-Electronics.
According to Bell, their radically new "Twistor" magnetic memory matrix
was vastly superior to conventional
ferrite core memories. It used hair-thin magnetic wires (more like
a flattened tape) interwoven with equally thin copper wires to store
and read out ones and zeroes. Doing so reduced manufacturing costs,
by eliminating the relatively expensive ferrite cores and eliminating
the difficult job of threading the read, write, and sense wires through
the core centers. Twistor memory also required less current to operate,
was denser, and weighed less than core memory. Within a decade CMOS
RAM was available to replace the magnetic memory, but from a reliability
Apollo space program selected magnetic core memory for the manned
February 1958 Radio-Electronics
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
New Twist in Memory Devices
Model (simplified) illustrates basic structure of magnetic "Twistor"
memory-magnetic and copper wires interwoven as in a window screen. Twisted
condition of the magnetic wire shifts preferred direction of magnetization
from a longitudinal to a helical path. One inch of twisted wire, thinner
than a hair, can store as much information as ten ferrite rings. "Twistor"
was invented at Bell Laboratories by Andrew Bobeck, M.S. in E.E. from
An ingenious new kind of magnetic memory
has been developed by Bell Laboratories scientists for the storage of
digital information. Known as the "Twistor ," it consists basically
of copper wires interwoven with magnetic wires to form a grid.
"Twister" gets its name from a characteristic of wire made of magnetic
material. Torsion applied to such a wire shifts the preferred direction
of magnetization from a longitudinal to a helical path. This helical
magnetization has been applied to produce a magnetic storage device
of unprecedented capacity for its size.
In a magnetic memory,
information is stored by magnetizing a storage element. In conventional
memories the storage elements consist of rings of ferrite. In the "Twistor,"
they consist of tiny segments of hair-thin magnetic wire. At each intersection
of the grid, one such segment is capable of storing a binary digit.
The "Twistor" is simple and economical to fabricate, and its
minute energy requirements are easily supplied by transistor circuits.
Bell Laboratories engineers see important uses for it in future telephone
systems which demand the compact storage of much information, as well
as in digital computers for civilian and military applications.
Bell Telephone Laboratories World Center of Communications Research