Well, if I were tasked with writing a definition of "DOSbook," it would be an extension of "DOS box." Just as a DOS box is a desktop or tower system that runs DOS, rather than WinDoze, Mac OS, Linux, XENIX, ChromeOS, other *nix, or OS/2 (or for that matter, TRSDOS, LDOS, OS-9, &c), a DOSbook...