chedit.txt

单片PLC,AT2581实现梯形图功能,可作为参考

        Alt-Original, the program will attempt to move the characters back to
        their original position.  The result is that the character that was
        added overlays the original character in that position.  Nothing has
        been hurt inside your character set, the original character is simply
        unavailable for single character commands (multi-character commands
        work fairly normally).

        There are several possible solutions to this problem, none of which
        we find satisfactory.  1) You could be prohibited from Getting
        characters into boxes that would be overlaid by Alt-R or Alt-O, but
        that is too arbitrary a restriction.  2) Getting a character into
        such a box could mean that the corresponding character will not be
        moved in an Alt-R or Alt-O, but that defeats the purpose of the
        "undo" commands.  3) the new character could be moved, but as the
        program does not know what the transformation is between the current
        and the restored locations (as there can be many Alt-H, Alt-V, and
        Alt-E commands between the stored locations and the current locations),
        the placement of the new character would have to be arbitrary.  This
        messes up your neat arrangement.  If you have a good suggestion for 
        this "problem", we would like to hear about it.



















4.2.8  "ROTATE" GROUP (enter the function keys indicated for the command):

All rotate functions move the character within its box.  Any row or column
of pixels that is rotated "off" an edge wraps back to the opposite edge,
to fill the row or column that is left vacant by moving the character.
If the cursor is in an empty box, the command has no effect.

F1 - Rotate the character 1 row down.
F2 - Rotate the character 1 row up.
F3 - Rotate the character 1 column left.
F4 - Rotate the character 1 column right.


4.2.9  "SHIFT" GROUP (enter the function keys indicated for the command):

All shift functions move the character within its box.  Any row or column
of pixels that is shifted "off" an edge is lost.  The row or column on the
opposite edge that is left vacant is filled with blanks.  If the cursor is 
in an empty box, the command has no effect.

F5 - Shift the character 1 row down.
F6 - Shift the character 1 row up.
F7 - Shift the character 1 column left.
F8 - Shift the character 1 column right.


4.2.10  "ROTATE ROW" GROUP (enter the keys indicated for the function):

All row rotate functions rotate an entire row of characters in the editing
matrix as if they were one extended character.  Occupied boxes do not have to
be contiguous.  Any row or column that is rotated "off" an edge wraps back to
the opposite edge, to fill the row or column that was left vacant.
The cursor does not have to be in an occupied location to use these commands.

Ctrl-F1 - rotate all characters in the current matrix row down one row.
Ctrl-F2 - rotate all characters in the current matrix row up one row.
Ctrl-F3 - rotate all characters in the current matrix row left one column.
Ctrl-F4 - rotate all characters in the current matrix row right one column.


4.2.11  "SHIFT ROW" GROUP (enter the keys indicated for the function):

All row shift functions shift an entire row of characters in the editing
matrix as if they were one extended character.  Occupied boxes do not have to
be contiguous.  Any row or column that is shifted "off" an edge is lost.  The
row or column on the opposite edge that was left vacant is filled with
blanks.  The cursor does not have to be in an occupied location to use 
these commands.

Ctrl-F5 - shift all characters in the current matrix row down one row.
Ctrl-F6 - shift all characters in the current matrix row up on row.
Ctrl-F7 - shift all characters in the current matrix row left one column.
Ctrl-F8 - shift all characters in the current matrix row right one column.













4.2.12  "ROTATE COLUMN" GROUP (enter the keys indicated for the function):

All column rotate functions rotate an entire column of characters in the
editing matrix as if they were one extended character.  Occupied boxes do not
have to be contiguous.  Any row or column that is rotated "off" an edge wraps
back to the opposite edge, to fill the row or column that was left vacant.
The cursor does not have to be in an occupied location to use these commands.

Shift-F1 - rotate all characters in the current matrix column down one row.
Shift-F2 - rotate all characters in the current matrix column up one row.
Shift-F3 - rotate all characters in the current matrix column left one column.
Shift-F4 - rotate all characters in the current matrix column right one column.


4.2.13  "SHIFT COLUMN" GROUP (enter the keys indicated for the function):

All column shift functions shift an entire column of characters in the editing
matrix as if they were one extended character.  Occupied boxes do not have to
be contiguous.  Any row or column that is shifted "off" an edge is lost.  The
row or column on the opposite edge that was left vacant is filled with blanks.
The cursor does not have to be in an occupied location to use these commands.

Shift-F5 - shift all characters in the current matrix column down one row.
Shift-F6 - shift all characters in the current matrix column up one row.
Shift-F7 - shift all characters in the current matrix column left one column.
Shift-F8 - shift all characters in the current matrix column right one column.


4.2.14  "ROTATE MATRIX" GROUP (enter the keys indicated for the function):

All matrix rotate functions rotate all characters in the editing matrix as if
they were one extended character.  Occupied boxes do not have to be contiguous.
Any row or column that is rotated "off" an edge wraps back to the opposite
edge, filling the row or column that was left vacant.  The cursor does not 
have to be in an occupied location to use the commands.

Alt-F1 - rotate the entire matrix down one row.
Alt-F2 - rotate the entire matrix up one row.
Alt-F3 - rotate the entire matrix left one column.
Alt-F4 - rotate the entire matrix right one column.


4.2.15  "SHIFT MATRIX" GROUP (enter the keys indicated for the function):

All matrix shift function shift all characters in the editing matrix as if
they were one extended character.  Occupied boxes do not have to be contiguous.
Any or or column that is shifted "off" an edge is lost.  The row or column
on the opposite edge that was left vacant is filled with blanks.
The cursor does not have to be in an occupied location to use the commands.

Alt-F5 - shift the entire matrix down one row.
Alt-F6 - shift the entire matrix up one row.
Alt-F7 - shift the entire matrix left one column.
Alt-F8 - shift the entire matrix right one column.












4.3  UNDO FUNCTIONS

The undo functions allow you to erase a mistake you just made, or let you
experiment with changes and quickly bring back an older version of the 
characters if you don't like what you see.

4.3.1  "UNDO" GROUP (enter the capital letter for the command):

Undo - undo the last change ONLY.  For example, you hit the Z (for Zero) key,
       the character will be erased, and U will restore the image.  If you
       hit the Z key and then press the spacebar (thus setting/clearing/xoring
       a pixel), using U will only undo the change in the individual pixel,
       not the erased character.  The cursor does not have to be in an
       occupied location to use the Undo command.

       Undo works by swapping images with the current screen image, so that
       Undo will Undo itself.  When a character is first called up for editing,
       the Undo image is set to the original image, so that Undo will do nothing
       until you have made a change.

       The Restore command (see below) has no effect on the saved Undo image.
       Undo, when doing multiple character editing, will Undo ALL characters
       at once.  Thus, if you use Alt-f (and fill all characters being edited),
       Undo will restore all of them, not just the current character.  Although
       it might be nice if each character had it's own Undo (along with a
       global Undo), for various technical reasons it is not practical. 

Restore - Like Undo, this command swaps the current screen image with a saved
       image.  Unlike the Undo command, however, restore affects only one
       character at a time, and the cursor must be in a occupied location.
       Also unlike the undo command, the saved image is not updated with
       every change of the character.  The saved image is only changed
       when you use the Restore, Alt-R (see below), the Keep command (see
       below), or Alt-K (see below).  Thus, you can start editing a character,
       Restore the original for comparison, Restore back the edited copy and
       continue editing.  Or, after editing, Restore back the original, edit
       the original into another version of the character, and use Restore
       to compare it to the 1st version of the character.

       Since both Undo and Restore swap saved images with the currently
       displayed image, the two functions may interact with each other.  For
       example, an Undo will move the previous image to the screen, and put
       the current image into the undo buffer.  A Restore will then move the
       screen image (from the Undo) to the Restore buffer, and place the
       image from the Restore buffer onto the screen.  A final Undo will then
       move the current screen image, which was in the Restore buffer, into
       the Undo buffer, and move the image in the Undo buffer, which was the
       original screen image, back to the screen.  In this way, the Undo
       saved image and the Restore saved image have been swapped, and the
       screen image is untouched.

Keep - keep the current screen image in the Restore buffer.  This allows you
       to save a copy of the current character for possible later restoration,
       without swapping screen images.  Keep will affect only one character,
       and the cursor must be in an occupied editing matrix location.












Original - replace the current character image with the image that the
       character had when it was for selected for editing.  This is the
       ultimate undo.  Original will only affect one character, and the cursor
       must be in an occupied editing matrix location.



4.3.2  "UNDO EVERYTHING" GROUP (enter the indicated keys for the function):

Undo  - Undo affects all characters being edited.  See the above description
        for details.

Alt-R - Restore all characters being edited.  This command is like the Restore
        discussed above, except that all current images are swapped with the
        saved images.  The same comments as above apply, except that the
        cursor does not have to be in an occupied location in the editing
        matrix.

Alt-K - Keep the current image of all characters being edited in the Restore
        buffer.  The same comments as for Keep above, except that the cursor
        does not have to be in an occupied location in the editing matrix.

Alt-O - replace all current screen images with the images that the characters
        had when they were first selected for editing.  This is the
        ultimate undo.  The cursor does not have to be in an occupied location
        in the editing matrix for this command.

Please refer to the caveat concerning these functions in section 4.2.7.





































4.4  "TRYOUT" MODE (enter "T" for the function):

    This mode allows you to "try out" the current character set by letting
    you type characters onto a blank screen.  Pressing the Esc key while in
    Tryout mode returns you to editing.

    When in Tryit mode, the keys on the numeric keypad

                  Home   Up    PgUp
                  Right        Left
                  End    Down  PgDn

    move the cursor, with Home, PgUp, End, and PgDn moving the cursor in a
    diagonal direction.  The cursor wraps to the opposite side of the screen
    when it passes the screen boundary.  Please note that keys such as Return 
    and Backspace do not have their expected function.  They will instead 
    display the symbol associated with with the ASCII value of that key.

    When Tryit mode is first entered, the screen will be filled with spaces
    (or whatever symbol is associated with the ASCII value 32).  After you
    leave Tryit, coming back later will present the screen as you left it.
    Thus, you can try a block of text, leave and edit the character set, then
    return and see how the text looks with the new characters without having to 
    retype them.

    Both the character set being edited and the machine's resident character
    set are available in Tryit mode.  See the functions listed below for
    details on using both.

    The following functions are available via the indicated function keys in
    Tryit mode:

    F1 - Clear the screen and display both the character set being edited and
         the machine's resident character set.

    F3 - Clear the screen to spaces and DO NOT replot the display.  The
         screen does not replot, to give you relief in the event that the
         space character is not blank.

    F2 - Toggle 40/80 column mode.  The screen starts out with 40 columns, and
         pressing the F2 key will switch the screen to 80 columns and back.
         Note that characters entered in the right half of the screen in 80
         column mode will not be displayed when you switch back to 40 column
         mode, but will still be there if you switch back to 80 columns.
         Clearing the screen via either F1 or F3 (see above) will clear the
         entire 80 columns, even if you are in 40 column mode.

    F4 - Toggle resident/editing character set on the displayed characters.
         For example, You can type a sentence in the editing character set,
         press F4 to see it in the machine's resident character set, then
         press F4 again to return it to the editing character set.  Another
         example is to use F1 to display both character sets, then F4 to
         switch them.













    F6 - Toggle resident/editing character set on characters being typed.
         When you enter Tryit mode, the characters you type are in the
         editing character set.  Pressing F6 will change the characters
         being typed to the machine's resident character set.  Pressing F6
         again will change back to the editing character set.

    F8 - Change the color of characters being typed (40 column mode only).
         When you start in Tryit mode, characters are white.  Pressing F8
         change the color of characters being typed from white to cyan to
         magenta, and back to white.  Characters in 80 column mode are
         available only in white.

    F10 - Help!  Print a brief description of the available function keys.




4.5  MISCELLANEOUS FUNCTIONS (enter the indicated keys for the command):
 
F10 - The help key.  It displays a list of the available commands, and a
      brief explanation of each.  The list is several pages long, and you
      can return to editing without looking through the entire help list
      by pressing the Esc key.

F9  - This will display the character codes (described above) superimposed
      on the characters in the editing matrix.  This lets you know the
      codes to use later in displaying the images you have created.  Pressing
      any key will return you to editing.

Esc - When you are editing charcters, you can return to the main menu by
      pressing the Esc key.




                         END OF DOCUMENT