Mass mailings could thereby be prepared with each letter copy individually addressed. Other add-on programs included SpellStar, a spell checker program, later incorporated as a direct part of the WordStar program; and DataStar, a program whose purpose was specifically to expedite creating of the data files used for merge printing. These were revolutionary features for personal computer users during the early-to-mid-1980s. A companion spreadsheet, CalcStar, was also produced using a somewhat WordStar-like interface; collectively, WordStar (word processing), DataStar/ReportStar (database management, a.k.a. InfoStar), and CalcStar (spreadsheet) comprised StarBurst, the first-ever office suite of personal computer programs. As a product enhancement, in the late 1980s WordStar 5 came bundled with PC-Outline, a popular DOS outliner then available from Brown Bag Software, Inc. in California. PC-Outline text had to be exported to a WordStar-format file, as the programs were not developed to be internally compatible. File types WordStar identified files as either "document" or "nondocument," which led to some confusion among users. "Document" referred to WordStar word processing files containing embedded word processing and formatting commands. "Nondocument" files were pure ASCII text files containing no embedded formatting commands. Using WordStar in "Nondocument Mode" was essentially the same as using a traditional text editor. WordStar 5 introduced a document-mode "print preview" feature, allowing the user to inspect a WYSIWYG version of text, complete with inserted graphics, as it would appear on the printed page. Installation Installation of early versions of WordStar, especially for CP/M, was very different from the approach of modern programs. While later editions had more-or-less comprehensive installation programs that allowed selection of printers and terminals from a menu, in the very early releases, each of the escape sequences required for the terminal and printer had to be identified in the hardware documentation, then hand-entered (in hex) into reserved locations in the program memory image. This was a fairly typical limitation of all CP/M programs of the time, since there was no mechanism to hide the complexities of the underlying hardware from the application program. To use the program with a different printer required re-installation of the program. Occasionally short machine-language programs had to be entered in a patch area in WordStar, to provide particular screen effects or cope with particular printers. Researching, testing, and proving out such installations was a time-consuming and knowledge-intensive process, making WordStar installation and customization a staple discussion of CP/M users' groups during that time. DOS versions