Artifact 4eb47f0701bf5e61a0111bf989394cd491a17698265944bbc09a5e5259e6d5c0:
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psl-1983/3-1/doc/nmode/nm-screen.ibm
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2020-04-21 19:40:01
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— Add Reduce 3.0 to the historical section of the archive, and some more
files relating to version sof PSL from the early 1980s. Thanks are due to
Paul McJones and Nelson Beebe for these, as well as to all the original
authors.git-svn-id: https://svn.code.sf.net/p/reduce-algebra/code/historical@5328 2bfe0521-f11c-4a00-b80e-6202646ff360 (user: arthurcnorman@users.sourceforge.net, size: 6676) [annotate] [blame] [check-ins using] [more...]
,MOD - R 44X (11 April 1983) <PSL.NMODE-DOC>NM-SCREEN.ibm PLA 97_LAS 80 0_FIR 2_INT 1 6.0_TYP 160 163 162 193_INP 12 101_MAR 2 ,END ,PRO 201 OUT 160_202 OUT 163_203 OUT 162_204 OUT 193 205 INP 12 101_206 INP 12 102 ,END ,DEFINE UNIT SPACE FUNCTION ,END 201/NMODE Manual (The Organization of the Screen) Page 2-1 202/2. The Organization of the Screen 201/NMODE divides the screen into several areas, each of which contains its own sorts of information. The biggest area, of course, is the one in which you usually see the text you are editing. The terminal's cursor usually appears in the middle of the text, showing the position of 202/point201/, the location at which editing takes place. While the cursor appears to point 203/at 201/a character, point should be thought of as 203/between 201/two characters; it points 203/before 201/the character that the cursor appears on top of. Terminals have only one cursor, and when output is in progress it must appear where the typing is being done. This does not mean that point is moving. It is only that NMODE has no way to show you the location of point except when the terminal is idle. One terminal function which 203/is 201/flexible is the choice of normal or inverse video for displaying text. Nmode lets you toggle this feature with the C-X V (203/nmode-invert-video201/) command. A few lines at the bottom of the screen compose what is called the 202/echo area201/. 202/Echoing 201/means printing out the commands that you type. NMODE commands are usually not echoed at all, but if you pause for more than a second in the middle of a multi-character command then all the characters typed so far are echoed. This is intended to 202/prompt 201/you for the rest of the command. The rest of the command is echoed, too, as you type it. This behavior is designed to give confident users optimum response, while giving hesitant users maximum feedback. NMODE also uses the echo area for reading and displaying the arguments for some commands, such as searches, and for printing brief information in response to certain commands. 202/2.1 The Mode Line 201/The line above the echo area is known as the 202/mode line201/. It is the line that usually starts with "NMODE something". Its purpose is to tell you anything that may affect the meaning of your commands aside from the text itself. NMODE major (minor) [bfr] file --pos-- * 202/major 201/is always the name of the 202/major mode 201/you are in. At any time, NMODE is in one and only one of its possible major modes. The major modes available include Text mode, Lisp mode (which NMODE starts out in), Recurse mode, Browser modes, and others. See Section 20.1 [Major Modes], page 1, for details of how the modes differ and how to select one. 202/minor 201/is a list of some of the 202/minor modes 201/that are turned on at the moment. "Fill" means that Auto Fill mode is on. 202/bfr 201/is the name of the currently selected 202/buffer201/. Each buffer has its own name and holds a file being edited; this is how NMODE can hold several files at once. But at any time you are editing only one of them, the 202/selected 201/buffer. When we speak of what some command does to "the buffer", we are talking about the currently selected buffer. Multiple buffers make it easy to 201/Page 2-2 NMODE Manual (The Mode Line) switch around between several files, and then it is very useful that the mode line tells you which one you are editing at any time. However, before you learn how to use multiple buffers, you will always be in the buffer called "Main", which is one that exists when NMODE starts up. If the name of the buffer is the same as the name of the file you are visiting, then the buffer name is left out of the mode line. See Section 16 [Buffers], page 1, for how to use more than one buffer in one NMODE. 202/file 201/is the name of the file that you are editing. It is the last file that was visited in the buffer you are in. The star at the end of the mode line means that there are changes in the buffer that have not been saved in the file. If the file has not been changed since it was read in or saved, there is no star. 202/pos 201/tells you whether there is additional text above the top of the screen, or below the bottom. If your file is small and it is all on the screen, --pos-- is omitted. Otherwise, it is --TOP-- if you are looking at the beginning of the file, --BOT-- if you are looking at the end of the file, or --nn%-- where nn is the percentage of the file above the top of the screen. If you are accustomed to other display editors, you may be surprised that NMODE does not always display the page number and line number of point in the mode line. This is because the text is stored in a way that makes it difficult to compute this information. Displaying them all the time would be too slow to be borne. However, once you are adjusted to NMODE, you will rarely have any reason to be concerned with page numbers or line numbers.