The conventional handwriting interface on pen computers uses two parts of the screen. The user must put a text cursor where they want to insert the text and then write on a separate pop-up window that recognizes ink. The separation of the two spaces may cause user fatigue and discomfort because it requires additional gaze and hand movement, which may cause a decrease in text editing efficiency and additional cognitive burden. As an alternative to alleviate these potential problems, we revisited and explored the concept of direct-writing interfaces as used in the past. In this study, we designed and implemented a direct- and indirect-writing text editor. Subsequently, we conducted an experiment to compare the usability of both text editors. The results showed that users’ gaze movement distance and frequency could be reduced, and constant time could be saved for each text editing operation using the direct-writing interface. In addition, participants preferred the direct-writing interface when simple and frequent text editing was required. However, the overall throughput of the text editing task was not affected. Lastly, we provided guidelines for further development of a direct-writing interface by combining empirical results, comments, and observations.