There are two different things called tabs in files. One is the ASCII Horizontal Tab character, ^I (09 Hex). This may be found in ASCII (Non-Document) files and is allowed in WordStar document files, mainly for compatibility with older versions of WordStar and for importing material containing ASCII tabs. The other is a Tab symseq (symmetrical sequence), a 12 byte sequence found only in WordStar document files. There are six kinds of symseq tabs: hard tabs, soft tabs, decimal tabs, center line tabs, right align tabs, and dot leader tabs. All symseq tabs contain information about their positioning on the page in HMI (Horizontal Motion Index) units â€” an HMI is 1/1800 inch. Such information is not contained in an ASCII tab: since it's just a single character it doesn't contain anything.
ASCII tabs are a nuisance: what they mean depends entirely on the software or hardware dealing with them. A common default for ASCII tabs is that they expand to the eighth column; that is to say, the next character after a tab is placed in the column after the next one that is a multiple of 8; that's how DOS displays them when it TYPEs a file, for instance. Some printers have this as a default, but most printers allow the tabs to be set in various ways. So there's no guarantee that an ASCII tab will be displayed on a terminal in the way it will print. Furthermore, software can be set to do various things with tabs (as WordStar can be set to display ASCII tabs with various tab stops in Non-Document mode). And of course, the eighth column has no meaning when one is dealing with proportional text. ASCII tabs are entered in a Non-Document by pressing the TAB key (unless variable tabs are set; see below), or ^PI; in a Document file they can only be entered with ^PI. I'm not sure how ASCII tabs are printed in a document; I think they are treated as though tab stops were set every .8 inches.
Symetrical Sequence (symseq) Tabs
Symseq tabs get into document files in different ways, depending on the sort of tabs they are. When you press the tab key while entering text you get a hard tab, decimal tab, or no tab, depending on whether the next tab stop on the line is a regular tab, decimal tab, or non-existent. Soft tabs, center tabs, and right align tabs get into the file as a result of formatting and are automatically added or removed as formatting changes. Dot leader tabs are put into the file by ^P. entered while entering text.
Since the symseq tab contains information about its absolute position, it can mostly maintain its position through font changes, and is to some slight degree device independent. WordStar can try to put it in the right place even on different printers. Of course, different font widths and different horizontal motion mechanisms in different printers can defeat this. Printing a file with a PDF other than that with which it was created is always a risky business.
Tab stops can be set in WordStar Document files in a variety of ways. In versions beginning with 5.5, the default settings have been in the default paragraph style (Body Text, unless this is changed in WSCHANGE at D A F B). They may be changed by using paragraph styles, the .tb dot command, or the .RR dot command (to insert a ruler line), or you can insert the current ruler line settings with ^OO and edit the result.
Searching For Tabs
Versions of WordStar before 7.0 could search and replace only ASCII tabs. 7.0 will search and replace any tab when ^PI inserts a ^I in the search field, and WordStar will insert a symseq hard tab, if a tab is replaced in the replace field. It is nice that the search and replace function learned to recognize symseqs, but it is practically useless for replacing many tabs, since one almost never wants to replace soft, center, right-align and dot-leader tabs along with the ASCII and hard ones, and the search function can't distinguish among the sorts of tabs.
Tab Behaviour in Non-Document Mode
The behavior of tabs in Non-Document files is controlled by a screen reached in WSCHANGE by entering D C B D.
This screen is one of those user-hostile parts of WSCHANGE designed to drive the user to distraction. It is scarcely explained at all, and exceedingly inconvenient to use; for most purposes, in fact, you are better off patching the table at E D C O N D directly. (Consult the PATCH.LST file before trying this.)
However, the idea here is a very convenient one: you can set WordStar's non-document handling of tabs and auto indenting according to the extension of the file you are editing. Thus (by default) if you are editing a non-document file with the extension .PAS (assumed to be a Pascal program source) WordStar will give you tab stops every two columns and auto indent ON by default. (It's convenient to make an addition to this table for the extension .WSM; I'm not sure whey they didn't do that in the factory shipped version.) One of the columns in this table is mysterious and unexplained -- variable tabs. When you use variable tabs, WordStar doesn't put the ASCII tab character (09 Hex) into the file when you press the tab key; it puts spaces in instead, and the tab stops are set according to the default ruler line at the label RLRINI. (You set this in WSCHANGE at D A E A.) You can still put an ASCII tab in with ^PI.
You can change the way Tabs display on the screen in Non-Document Mode, by pressing ^OI. You can choose to have tabs set at every 2, 4, 8, or 16 columns. Note that this will only affect the way the tabs are displayed while editing. It will not affect how they print, no matter how you print the file.
WordStar will print tabs in a Non-Document file according to the file extension, provided you tell it in the print dialogue box that you are printing Unformatted Text (7.0) or Non-Document (earlier versions). When you do this, WordStar also prints any lines with a dot in the first column (dot commands).
Beware of modifying the table of file extensions, tab settings, and autoindent settings, however. If you tell WSCHANGE you want to modify this table it wipes out the whole thing and asks you to enter the information for the whole table one item at a time. As you do so, the previous version of the table scrolls off the screen. This is fine if you want to kill the table, but not so much fun if you just want to add an entry at the end of it.