Typeball

Typeball refers to the typing element used in certain electric typewriters, most notably the IBM Selectric series. Rather than using fixed type bars, the Selectric employed a replaceable spherical element—the typeball—with the entire character set arranged on its surface. When a key was pressed, electromagnets rotated and tilted the ball so that the desired character lined up with the typing position, and a type hammer struck ink from a ribbon onto the page, producing the character. After each keystroke, the ball realigned for the next character.

The typeball could be swapped to change fonts or languages, allowing rapid font changes without replacing the entire typewriter mechanism. The first IBM Selectric, introduced in 1961, popularized the approach and set a standard for interchangeable font elements. Later models, such as the Selectric II, expanded font options and language support through additional typeballs and compatible components.

Impact and legacy: The typeball design represented a significant shift in typewriter technology, offering higher printing speed, improved alignment, and easier customization compared to traditional type-basket mechanisms. Its influence extended into later printer and word-processing concepts that used a centralized, interchangeable glyph element. In contemporary references, typeball is primarily a historical term cited in studies of typewriter design and the evolution of electronic printing technologies.