Since the late 20th century, many attempts have been made to integrate the simplicity of a notebook with the editing, searching, and communication capacities of computers through the development of note taking software. Laptop computers began to be called notebooks when they reached a small size in the mid 1990s, but they did not have any special note-taking ability. Most notably Personal digital assistants (PDAs) came next, integrating small liquid crystal displays with a touch-sensitive layer to input graphics and written text.