magnetic drum

Instead, said Dr Johnson, he invented magnetic drum storage that used a small brass drum coated with nickel.

There are two features that might be mentioned: the magnetic drum for storing permanent information and the cathode-ray tubes for storing information produced in the course of a calculation.

The magnetic drum will hold 650,000 binary digits and each of the eight cathode-tubes sixty-four twenty-digit numbers.

Oedipus could hold 160,000 characters of particular phrases on its magnetic drum memory and a further 60,000 characters in its read-only associative store, which consisted of huge numbers of semiconductor diodes.

Then the words were recorded on a revolving magnetic drum.