Chapter 7 Editor CHAPTER 7 EDITOR The editor lets you create or edit text in the capture buffer. You may also edit text loaded from disk files. The editor can be used with any standard Apple text file including the macro script, function key, help, and phone list files used by this program. The editor is a full-screen editor, which is similar to the editor portion of a word processor. It displays a screen page of the part of the text being edited. You may enter edit commands to move through the text to perform editing changes. Since a lot of features are available, there are many editing commands. However, it is not necessary to learn all of the commands to use the editor. You need only a few of the basic commands to perform most editing tasks. The capture buffer and the editor buffer are the same so you may edit any text captured while online by simply running the editor. Any text changes made with the editor will be made directly to the text in the buffer. When you exit the editor, the newly edited text remains in the buffer and can be transmitted, viewed, saved to disk, or re-edited. If you want to keep a copy of the original unedited text, you must save the buffer contents before editing it. The editor does not automatically save a backup copy of the original file. Remember that the buffer will be cleared after it is saved to disk while in the terminal mode so you will have to restore the buffer after the save. If you save the buffer to disk while in the editor command mode, the buffer will not be cleared and you do not haveto restore it. The editor is compatible with all of the screen formats used by MODEM MGR. This includes the 40-column, 80-column, 64-column, and split video modes, as well as all eight of the Ultraterm video formats. Switching between Ultraterm video modes can be accomplished in the editor command mode. To perform editing, you must move from the terminal mode to the editor command mode. From the editor command mode, you can then enter the editor. A summary of the commands to move from one mode to the other is summarized below. TERMINAL ---Z---> EDITOR ----E----> COMMAND COMMAND EDITOR MODE <---Q--- MODE <--[ESC]-- Enter the Z command to move from the terminal command mode to the editor command mode. After a few seconds of disk activity, the editor will be loaded. You will see an "Edit command? -->" prompt displayed. If you issue an E command in the editor command mode, you will move to the editor where you can perform text editing. You can escape from the editor back to the editor command mode by pressing the [ESC] key. Finally, you can return tothe terminal mode by entering Q (for Quit). Although these sequences of commands appear complicated, there are menus and prompts to remind you how to move to and from the editor. After some usage, you will easily remember these commands. Figure 7-1 shows a menu of commands in the editor command mode. You can display this menu in the editor command mode by entering a ? when the "Edit command? -->" prompt is displayed. Figure 7-2 shows a menu of editing commands in the editor. You may display this menu in the editor at any timeby entering a [CTRL] Q. EDIT COMMANDS C:Clear buffer D:Disk functions E:Editor P:Printer ON/OFF Q:Quit edit R:Restore buffer S:Space in buffer V:View buffer ?:This menu >:Video format Figure 7-1. Edit command menu EDITOR COMMANDS ^S Char Left * ^W Line Up ^D Char Right * ^Z Line Down ^E Line Up * ^R Page Up ^X Line Down * ^C Page Down ^A Word Left ^T Top of File ^F Word Right ^B Bottom of File ^I Insert ON/OFF ^G Delete Char ^O Find/Replace ^L Delete Line ^P Put control char ^N Del to line end ^V Video format ^O Find/delete ^Y Yank disk file ^@ Del to begin/end ^Q Quick menu [DEL] Del char left * Use arrow keys alsoFigure 7-2. Editor Menu EDITOR COMMAND MODE You can enter the editor command mode by selecting the Z command while you are in the terminal command mode. In the DOS 3.3 version, the work disk must be in the same drive that the program was started in. If it is not in the same drive, the editor module will not be found and the program will attempt to return to the terminal mode. If the work disk is not in the same drive, the terminal program module will not be found cither and the program will halt. An error message will prompt you to insert the work disk in the drive and press any key to re-start the program. After you return to the terminal mode with the work disk in the proper disk drive, you can try to enter the editor command mode again with the Z command. When you are in the editor command mode, the following edit command prompt will be shown: Edit command? --> The edit command menu in figure 7-1 shows all of the available commands in the editor command mode. To execute an editor command, enter the single letter in the menu associated with each command. For example, you can clear (erase) the text buffer by entering the letter C. You do not have to enter [ESC] before each editor command. Many of the editor commands are the same as commands used in the terminal mode. Therefore, only a brief description will be given below for each editor command. C: Clear buffer This command clears (erases) the contents of the text buffer. If you have used this command by mistake and wish to restore the text buffer, see the R command. D: Disk functions This command allows you to perform disk functions in the editor command mode. You may read or write text or binary files to or from the text buffer. Any disk file read to the text buffer will be appended at the end of any existing text in the buffer. (If you wish to insert a text file elsewhere in the buffer, you can use the control-Y command in the editor. This will be described in the editor section). When you enter the D command, this program will display a disk functions menu. The disk functions are exactly the same as those supported in the terminal command mode with one exception: when the text buffer is written to disk, the text buffer is not automatically cleared. This allows you to make periodic saves while editing without losing the contents of the buffer. Since these disk commands are exactly the same as those in the terminal mode, they will not be discussed again. E: Editor This command places you in the editor where you may perform editing of the text. A full description of the editor is presented later in this chapter. P: Printer ON/OFF This command toggles printing on or off. Use this command to print the contents of the text buffer when the V (View buffer) command is executed. You can perform printing while in the editor command mode, but not while in the editor mode. Q: Quit edit This command allows you to quit the editor command mode and return to the terminal command mode. R: Restore buffer If you have cleared the buffer (using the C command) and want to restore the buffer to the condition before it was cleared, enter this command immediately. If this command is entered after new text has been added to the buffer, the buffer may end up with a combination of newly added text overlaying the earlier text that was cleared and restored. S: Space in buffer This command will display the space used and remaining in the buffer in bytes. The first decimal number is the number of bytes (characters) used and the second decimal number is the space available for additional bytes. A CR/LF combination uses two bytes. V: View buffer This command lets you view the contents of the text buffer. The text will scroll on the video screen from the beginning to the end. You may control the scrolling speed by pressing any one of the keyboard number keys from [1] (slow) through [9] (fast). You can stop and restart the scrolling by pressing the space key. You can cancel the view mode by pressing the [RETURN] key. If you type [CTRL] C while viewing, all control characters (except control-J and control-M) will be displayed as the circumflex or caret character followed by the associated letter character. For example, control-G will be shown as ^G. If you type [CTRL] X, all control characters (including control-J and control-M) will be displayed as the circumflex character followed by the associated letter character. You may toggle the printer on or off by entering [CTRL] P while the text is scrolling. ?: This menu This command displays the edit command menu. >: Video format This command applies if you are using the Ultraterm video card in the normal (non-split) format. You can select any of the eight Ultraterm video formats by entering this command followed by a number from 1 to 8. For example, the command 8 will select the 128-column by 32-row mode. Some video cards will switch between 80-columns and 64-columns if you enter this command followed by the number 0 or 1. EDITOR The editor is where you accomplish the actual editing of the text. Enter the editor by selecting the E command while you are in the editor command mode. You can type the [ESC] key to exit from the editor back to the editor command mode. When you enter the editor, the video screen will initially clear and the cursor will appear at the top left corner of the screen. If any text is in the buffer (previously loaded from a disk file or captured from an online session), it will appear on the screen. If the buffer is empty, nothing will appear on the screen except the cursor. DISPLAY If you captured text in the buffer during an online session, then each video line of the text is probably terminated by a CR/LF combination. The CR/LF combination is not represented directly as a visible character on the video screen. It is represented by a blank space at the end of the line. The cursor can be placed on the space which represents the CR/LF combination at the end of the line. If the length of the text line is greater than the video screen width, the text will wrap around to the next line below. The cursor will always appear on a visible text character except when it is positioned on one of the following: 1) Space character 2) CR/LF combination 3) End of file (or empty buffer) If the cursor is not at the end of the file and the cursor appears to be on a "blank", there is either a space character or a CR/LF combination there. All control characters in the text (except control-J and control-M) are represented by a circumflex or caret character followed by the letter character associated with the control character. For example, a control-G will appear as ^G. Control characters in the edited text will be discussed in more detail later in this chapter. You may enter text directly from the keyboard. The text you enter will appear on the screen and will be inserted into the text buffer. We recommend you enter a [RETURN] at the end of each video line before the right margin is reached. (Like using a typewriter). This places a CR/LF combination at the end of each video line. The editor does not automatically insert a CR/LF during keyboard entry. You may allow a sentence to wrap around to the next line below without entering a [RETURN], but this may slow some editing functions if a line is wrapped too many times. The editor does provide a formatting command (described later) which will reformat the text into the number of columns you specify. Reformatting will place the CR/LF in the proper position near the end of each video line so that word splitting does not occur at the right margin. A description of each of the editor commands is given below. We recommend you load a text file into the buffer and use each editing command as you read its description below. There is a file with editing instructions called TUTOR which you can load and read as you edit it. MOVING THE CURSOR You can edit the text by moving the cursor to the desired location in the text and performing the edit function. There are several ways you can move the cursor through the text. You can move the cursor one character to the left or right by using the left or right arrow keys on the keyboard. You can move the cursor one line up or down by using the up or down arrows on the keyboard (not available on the ][ or ][+). There is another way you can move the cursor using the [CTRL] keys. This method has been used with several popular word processors. Notice the arrangement of the following keys on the keyboard: E CTRL S D X The S, D, E, and X keys are elements of a diamond pattern on the keyboard which correspond to the left, right, up, and down directions, respectively. You may move the cursor one character to the left by entering [CTRL] S. To move the cursor to the right, use [CTRL] D. You may move the cursor oneline up by entering [CTRL] E or one line down by entering [CTRL] X. The relative position of these keys on the keyboard corresponds to the direction the cursor will move in response to your control key commands. Depending on your preference, you may use the arrow keys or the control keys to move the cursor. If the cursor is in the far right column or on a CR/LF character and you try to move it further to the right, it will move down to the first column of the next line. If the cursor is in the far left column and you try to move it further to the left, it will move to the end of the text on the line above. If the cursor is on the bottom video line and you try to move it one line down, the text will automatically scroll up one line. If the cursor is onthe top video line and you try to move it one line up, the text will automatically scroll down one line. You can never move the cursor off the video screen. If you try to move the cursor off-screen, the text will scroll and the cursor will end up on the next line of text. If you move the cursor to the beginning of the text file, you will not be able to move the cursor further to the left. If you move the cursor to the end of the text file, you will not be able to move the cursor further to the right. You can never move the cursor beyond the file or to a position where there is no text. (The CR/LF "invisible" character is considered part of the text wherever it occurs.) CURSOR TO WORD LEFT OR RIGHT There are times when you may wish to move the cursor more than one character at a time to the left or right. Let us now use the adjacent A and F keys on the keyboard as control keys. E CTRL A S D F X This diagram shows the relative position of the A and F keys along with the previously discussed S, D, E, and X cursor keys. Notice the F key is on the far right and the A key is on the far left. If you enter [CTRL] F, the cursor will move to the first character of the next word to the right. If you enter [CTRL] A, the cursor will move to the first character of the present or next word on the left. ([CTRL] A will not do this if it is being used as the shift key on the ][ or ][+). SCROLL ONE LINE UP OR DOWN One advantage of using these control keys for cursor control is the other editing commands which control text positioning are built around these commands in a logical fashion. There are several editing commands which control the text displayed on the video screen. For example, the W and Z control keys allow text scrolling. W E CTRL A S D F Z X Note the W key is above the Z key on the keyboard. If you want to see the next line beyond the top of the screen, the [CTRL] W command will scroll the text down one line so you can see the next line at the top of the screen. If you enter [CTRL] Z, the text will scroll up one line and you will see the next line at the bottom of the screen. Therefore, if you want to see thenext line at the top or bottom of the screen, enter [CTRL] W (top) or [CTRL] Z (bottom). When these two keys are used to scroll one line up or down, the cursor will remain in the same position unless the cursor is on the top or bottom line. Since the cursor can never be forced off the screen, the cursor will always move up or down to remain on the screen whenever the line it is presently on is scrolled off the screen. To obtain continuous scrolling of the screen, you may use either of these commands along with the keyboard repeat function to scroll the text up or down. SCROLL ONE SCREEN PAGE UP OR DOWN Suppose you want to move to the previous or next screen page of text. You can use the R and C keys on the keyboard. W E R CTRL A S D F Z X C Note the R key is above the C key. If you want to see the screen page of text that precedes the present text displayed (this text can be imagined as being "above" the present display), enter [CTRL] R. If you want to see the text that is "below" the present display, enter [CTRL] C.If you are using the 24-line display, one screen page is exactly 24 lines. If you are using the split display, one screen page will be 19 lines. If you are using any of the Ultraterm video modes with 24- to 48-line displays, the screen page will be equal to the number of lines in the display format. In other words, the screen paging commands will always show the previous or next screen page of text without overlap or loss of lines. MOVE TO TOP OR BOTTOM OF FILE The last commands which control text positioning on the video screen involve the T and B keys. W E R T CTRL A S D F Z X C V B If you enter [CTRL] T, the editor will move to the top (beginning) of the text. If you enter [CTRL] B, the editor will move to the bottom (end) of the text. This pair is easy to remember (T for top and B for bottom). If there is a long file in the buffer, it will take several seconds to move from one end of the file to the other. ENTERING TEXT FROM THE KEYBOARD You may enter text directly from the keyboard into the file being edited. You must first position the cursor at the desired location where you want to key the text in. There are two modes of keyboard entry--the insert mode and the non-insert (strike-over) mode. You can enter the [CTRL] I command to toggle between the insert and non-insert modes. The mode you select will be displayed momentarily at the bottom left of the screen. The cursor will blink in the non-insert mode if you are using the full-screen video. The cursor will not blink if you are using the split-screen video. KEYBOARD INSERT MODE In the insert mode, any characters you type on the keyboard will be inserted at the cursor position. As you type additional characters, they will push the remainder of the line to the right. If the line becomes wrapped around because of the additional characters, subsequent lines will be pushed down. If you type the [RETURN] key, a CR/LF will be inserted and all of the lines beyond the cursor will be pushed down one line. To keep up with a fast typist, the screen display update is preempted by the display of the new characters typed in. If you type characters rapidly, the present line display will be updated but the display of the lines below will not be updated until you pause. This allows you to see immediately what is typed in without any annoying delays for screen updating. KEYBOARD NON-INSERT (OVERSTRIKE) MODE In the keyboard non-insert mode, any character you type will replace the existing character at the current cursor position. WARNING FOR FAST TYPISTS If you are a fast typist and you depend on the keyboard rollover feature, you will sometimes have as many as three keyboard keys depressed simultaneously. In some cases, this will generate four characters instead of three. This is a characteristic of the keyboard. For example, if you rapidly type the U, the I, and the space bar in any order on a //e or //c keyboard without releasing each key, you will also generate a control-K character. This is the same as the "up arrow" key. If you are using the MODEM MGR editor, you will see the U,I, and space on the screen; you will also see the cursor jump up one line. There are other key combinations which will generate an extra confusing control character. DELETE CHARACTER You can delete a character under the cursor by entering the [CTRL] G command or you can delete the character to the left of the cursor by typing the [DELETE] key. The remainder of the line will shift to the left to close the "hole" left by the deleted character. You may delete a CR/LF combination by placing the cursor on the "blank" space representing that combination and entering the [CTRL] G command. This will pull up all of the lower lines. You may delete control characters also with this command. If you delete several characters rapidly in a long line which wraps through several video lines by using the keyboard repeat function, the display of the line containing the characters being deleted will preempt the display of the wrapped lines until there is a pause in the command or a CR/LF is deleted. This will provide efficient display of the character delete operation without delays caused by screen updating. DELETE LINE The [CTRL] L command will delete the video line that the cursor is presently on. All of the lines below the cursor will move up one line and the cursor will end up a the far left of the next line. Only one video line will be deleted by this command even if the deleted line was a long line wrapped through several video lines. DELETE TO LINE END The [CTRL] N command will delete the remainder of the line from the cursor position to the end of that video line. A CR/LF combination will be placedat the current cursor location. FIND/DELETE STRING The [CTRL] O command will find any string you specify and delete it. It can delete every occurrence of this string wherever it is found from the current cursor position to the end of the file. It can also find all of the string appearances and delete only those you wish to have removed. When you enter this command, the program will ask you to enter the string to be deleted. The string must be 30 characters or less in length and can include any control characters except escape, control-M, control-H, or control-J. You can quit this command if you don't enter any string and just enter [RETURN]. You must enter the string in upper and lower case characters exactly as the string you wish to delete. After you enter the string, you will be asked to enter [RETURN] if you wish to delete the string. After entering [RETURN],you will be asked whether you wish to delete all occurrences of the string or only some occurrences. If you specify A (for All), the editor will initially display the current screen of text. Then it will search through the file from the current cursor position to the end of the file and delete the string wherever it occurs. While it is doing this, it will display the video page of text where the string was found. This will give you some idea of the number of occurrences of the string in the text. Although the pages where the strings are found will be displayed, the actual removal of the string will not be shown. When the string search is completed, the cursor will be at the end of the file. If you specify S (for Some), the program will initially display the current screen of text. Then it will search through the file from the current cursor position to the end of the file and stop wherever the string is found. It will display the text where the string was found with the cursor positioned at the start of the string. You will now have a choice of deleting the string or leaving it undisturbed and searching for the next occurrence of the string. If you depress the [SPACE] key, the string will be deleted, the display will be updated to show the deletion, and the search will continue for the next occurrence of the string. If you depress the [RETURN] key, the string will not be deleted and the string search will continue. If any other key is depressed, it will be considered as an edit command or keyboard entry and the delete command will be cancelled. If you wish to delete a string from the entire file, remember to place the cursor at the beginning of the file before executing this command. The find/delete command always starts from the present cursor position and proceeds to the end of the file. The find/delete command is useful in removing certain undesirable control characters which may appear in some text files. For example, the ^@ null or ^G bell characters can be easily removed from a file with a few command keystrokes. DELETE TO BEGINNING OR END OF FILE You can use the [CTRL] @ command to delete all of the text from the beginning of the file up to the current cursor position or to delete all of the text from the current cursor position to the end of the file. Since the @ character is a shifted character, you must simultaneously depress the [CTRL] key and the [SHIFT] key as well as the @ key in order to enter this command. When you enter this command, the following will be displayed: DELETE 1:Front of file 2:Rest of file 1 or 2? --> Enter 1 to delete everything up to (but not including) the character at the cursor or enter 2 to delete everything beyond (and including) the character at the cursor. Enter [RETURN] if you don't want to delete anything at all. If you select 1 or 2, you will be asked if you are sure you want to execute this command. Enter Y (for Yes) or N (for No). You can use this command to isolate a block of text for later insertion into another text file. Move the cursor to the beginning of the desired block and delete all of the text preceding the block. Then move the cursor just past the end of the desired block and delete everything beyond the block. Finally, save the block to disk. This command is potentially dangerous because you can delete a large portion of your file. If you want to keep the original file, be sure you have saved it to disk before using this command. FIND STRING You can use the [CTRL] O command to find a string in the text. This command will find every occurrence of the string or just the next occurrence. After you enter the [CTRL] O command, you must enter the string. The string can include control characters (except escape, control-J, control-M, and control-H) and must be 30 characters or less in length. You must enter the string exactly as desired in upper and lower case letters followed by [RETURN]. After you enter the string followed by [RETURN], enter [ESC]. Do not enter [RETURN] a second time here because that will delete the string from the text instead of just finding it. Prompts are shown to help you select the correct key entries. If you want to quit this command, do not enter any string--just enter [RETURN]. The present screen of text will be displayed until the first occurrence of the string after the current cursor position is found. The text containing the string will then be displayed with the cursor on the first character of the string found. To find the next occurrence of the string, depress the [SPACE] key or the [RETURN] key. If any other character is entered, it will be considered an editing command or a keyboard entry and the search will be terminated. FIND/REPLACE You may also use the [CTRL] O command to replace a string with another string. This command will perform this for every instance where the string occurs or in selected instances. After you enter the string to be found, enter the replacement string. You will then be asked whether you want the string replaced in all instances or just in some instances. If you answer A (for All), the current screen of text will be displayed initially. If the string is found, the text page containing the string will be displayed, the string substitution will be made, but the string substitution will not be displayed. After the file has been searched to the end, the end of the file will be displayed. If you answer S (for Some), the current screen will be displayed until the string is found. The screen will then show the text page where the string was found and the cursor will be positioned over the first character in the string. If you enter [SPACE], the substitute string will replace the string and the new string will be displayed in place of the old string. The search will then continue for the next occurrence of the string. If you enter [RETURN] the string will not be replaced and the search will continue for the next occurrence of the string. If any other key is depressed, it will be considered a keyboard entry or edit command and the string find/replace will be discontinued. FORMAT CHANGE Suppose you are using an 80-column video display and the text in the buffer consists of brief lines significantly shorter than 80 columns in length or long lines which split words where the line wraps around the right margin. You may wish to reform the lines so they are closer to 80-columns in length without splitting words at the right margin. The [CTRL] V command will format any or all of the lines in the text. Formatting will reform a line so it extends all the way towards a redefined right margin without splitting a word. Any word that might be split at the right margin is moved down to the beginning of the next line. You may specify any margin width from 40 to 160 columns. You can format text for any number of columns regardless of the number of columns in your video display. For example, if you have an 80-column display, you can format the text into 40-, 80-, or even 160-columns. Of course the text formatted for 160 columns will wrap around with split words when displayed on an 80-column screen, but the same text will be properly formatted when displayed on a 160-column screen. When you execute this command, you will have to enter the column width for the new format. If you don't want to perform the format operation, enter [RETURN]. The column width must be between 40 and 160 columns. You will next be asked if you want to format all of the lines following the present cursor position or just some of the lines. If you answer A (for All), then all of the lines starting from the line the cursor is on to the last line in the file will be reformatted. As the reformatting proceeds, it will be displayed on the screen. Initially, formatting will proceed slowly down the screen because the lower screen is being redisplayed after each line is formatted. However, after the last line on the display is formatted, it will move along more rapidly. If you answer S (for Some), the cursor will remain on the present line. If you want that line formatted, depress the [SPACE] key. The line will be formatted and the cursor will move to the next line. If you don't want that line formatted, depress the [RETURN] key and the cursor will move to the next line. If you enter any other character, it will be considered a keyboard entry character or an editing command and the formatting operation will end. If you don't want the formatting command to join the end of one paragraph with the beginning of the next paragraph, use double spacing between paragraphs in the original text. YANK DISK FILE You can yank a text file from disk into the text being edited by using the [CTRL] Y command. The disk text file will be inserted into the edit file at the current position of the cursor. This feature can be used to insert a block of text from another file. After you execute this command, you will have to enter the filename or pathname of the disk text file. If you decide not to yank in a disk file, enter [RETURN]. The disk file must be a conventional text file (a binary file cannot be used). After the disk file is inserted into the buffer, the cursor will appear at the end of the newly inserted text. If the buffer does not have enough room to completely load the disk file, it will load as much as it can until the buffer is full. EDITOR MENU You can display the editor menu shown in figure 7-2 in the editing mode by entering a [CTRL] Q. This is a summary of all of the editing commands. Type any key to return to the editor. SPECIAL CHARACTERS You cannot enter some special characters with the Apple ][ or ][+ keyboard. The terminal mode provides for translation of control characters to special characters with the keyboard translation that is set up with the INSTALL program. However, that translation is disconnected in the editor because most of the control characters are used for editing commands. If you want to insert one of these special characters into the text, enter a [CTRL] P followed by one of the following letters: Letter Special Character Key Character (hex) < [ $5B / \ $5C > ] $5D N ^ $5E - _ $5F ' ` $60 ( { $7B ! | $7C ) } $7D = ~ $7E # rub-out $7F P @ $40 V ^\ $1C W ^] $1D X ^^ $1E Y ^_ $1F For example, you can enter a [ character by typing a [CTRL] P followed by a <. All of these special characters can be entered directly with the //c, //e, or IIGS keyboard so it is not necessary to use the [CTRL] P prefix key unless you have a ][ or ][+. If you have a keyboard enhancer on your ][ or ][+, you may enter some of these special characters directly. The last four special characters in the list above are entered on the //c, //e, or IIGS directly as control characters. These are listed below for reference. //c or Special Character //e Key Character (hex) [CTRL] \ ^\ $1C [CTRL] ] ^] $1D [CTRL] ^ ^^ $1E [CTRL] _ ^_ $1F CONTROL CHARACTERS All control characters in the text except for control-M (CR) and control-J (LF) will be shown as a circumflex or caret character followed by the associated letter. For example, a control-H will be displayed as ^H When you move the cursor to a control character, it cannot appear on the ^, but will always appear on the associated letter. If you can place the cursor on the ^ then the ^ is not associated with a control character, but is simply a caret character. A control character is a single character that takes two character spaces on the video display. You may find several unexpected control characters in your editor display. For example, you may find ^@ characters present. This represents the null control character (00) which is transmitted by some remote systems to create a delay. You can prevent this character from being captured in your buffer as described in chapter 5. You may delete all of these null characters from the file by using the [CTRL] O command. When you are asked to enter the string to delete, enter a control-@. Some other common control characters you may find in your text are ^G (bell), ^H (backspace), and ^I (tab). For example if you see the following: aple^H^Hple It means someone had difficulty trying to type "apple". Since most of the control characters are used as editing commands, how can you enter a control character into the text being edited? This can be accomplished by preceding the control character with a [CTRL] P. For example, if you want to insert a control-G into the text, enter [CTRL] P followed by [CTRL] G. You can delete control characters by the usual method of placing the cursor on the control character (the letter following the ^) and using [CTRL] G to delete the control character. Since the video display of the control character takes two character spaces, the remainder of the line will pull in two spaces after the control character is deleted. This is true even if the control character display is wrapped around the right margin or wrapped into or out of the video screen. REPEAT KEYS The editor uses a software keyboard buffer to store keystrokes. This insures all keystrokes are accepted even if you type them while some of the slower screen operations are taking place. For example, if you want to delete eight lines of text, you can enter [CTRL] L eight times as fast as you can and all eight commands will be executed. However, if you use the repeat function of your keyboard, you may enter more commands than you wanted to and delete more lines than you wish you had. Therefore, you should be careful about using the repeat key with delete commands. CR/LF EXPANSION Normally the text in the buffer has lines terminated in the CR/LF combination. However, if you captured the text during a terminal emulation operation, it may contain single CR and single LF characters. When the editor is entered, CR or LF characters in the text buffer will be converted in the following way: 1) CR/LF combinations will be unaltered. 2) Single CR characters will be converted to a CR/LF combination. 3) Single LF characters will be converted to a CR/LF combination. Since a CR/LF combination takes up two characters, any text in the buffer which contains single CR or LF characters will increase in size. The amount of the increase depends on the number of conversions of single LFs or CRs to the CR/LF combination. If the size increase results in a full buffer, an error message will be displayed. If you want to preserve any single CR or LF characters in the capture buffer, save the text in a binary file before editing it. VIDEO "NOISE" Some video cards will generate a dark dash or light dot on the screen whenever a character is written to the video RAM. If only a few characters are being written, this will not be apparent. However, if a lot of characters are being written rapidly, this becomes obvious. In the editor, the entire screen is sometimes re-written even when there is just a minor change in one of the lines. For a 80X24 video format, this means 1920 characters are written to the video RAM even though the screen content is not significantly changed. This may cause a momentary burst of "video noise". During scrolling, this effect is more pronounced in the splitscreen modes. The Ultraterm and Apple video cards will not exhibit this characteristic.