WordStar was a word processing program produced by MicroPro International, first released for CP/M microcomputers around 1978 and 1979 and later ported to MS-DOS. Through the early 1980s it was the dominant word processor on small business computers, and for many users it was the application that justified buying a computer for writing. The WordStar 3.3 Reference Manual from 1983, archived at bitsavers, identifies the publisher as MicroPro and documents the program in full detail.
WordStar ran on the character terminals of the era, which had no mouse and few special keys, so it controlled the cursor and the document through combinations of the Control key with ordinary letters. The most famous of these was the so-called diamond: Ctrl-E, Ctrl-X, Ctrl-S, and Ctrl-D moved the cursor up, down, left, and right, arranged in a diamond shape on the keyboard so that the hand could navigate without leaving the home row. The reference manual lays out this command set, including the cursor-movement, scrolling, block, and formatting commands that defined the WordStar interface.
The program was notable for being, in the language of the day, fairly close to what-you-see-is-what-you-get for its time. It showed page layout, margins, and on-screen formatting markers, and it used dot commands, lines beginning with a period, to control printing instructions such as page breaks and headers. This combination of on-screen editing and embedded print control made it practical for producing real documents on the limited hardware of the late 1970s and early 1980s.
WordStar’s dominance faded over the second half of the 1980s as WordPerfect and later Microsoft Word gained ground, especially as graphical interfaces arrived and the diamond key conventions mattered less. The company also stumbled with a poorly received rewrite. But WordStar had already shaped a generation of users and writers, and its control-key conventions persisted in later editors and as optional key bindings for years afterward.
WordStar is remembered both as a commercial milestone, one of the first true blockbuster applications for personal computers, and as a design landmark, a demonstration that a serious editing program could be built around a consistent, learnable keyboard command language. The archived MicroPro manuals remain the primary record of how the program actually worked.