Why would Sawyer—and Michael Chabon and Anne Rice and Arthur C. Clarke and James Gunn—keep using a DOS program, decades past its last update, with quite a few workarounds needed for modern systems? Because it's meant to help writers keep on writing. Like Vim or Emacs, it can be used with a system of keyboard commands entirely without a mouse; unlike Vim or Emacs, it is built for words and paragraphs, not code. Sawyer detailed this in
an essay on his site,
republished on Ars Technica in 2017. WordStar puts powerful commands near your strongest fingers and makes navigating text, bookmarking, and leaving unpublished notes for yourself far easier than WordPerfect, Word, or almost anything since.
If you download the entire 700-ish MB package, you can see all of this for yourself. Sawyer's README (included in full on the archive page) details the tweaks he recommends for getting WordStar running in DOSBox-X, like setting the screen to 80 columns and 25 lines of text, picking a good font, and switching CapsLock and Ctrl keys to make use of WordStar's home-row-oriented shortcuts. There's even a utility for converting WordStar files to something Word or other modern tools can read, handily named CONVERT.EXE.