You must know:

      The number of rows and columns displayed on your terminal
      How to position the cursor to home (the upper left corner of
         the screen) and clear the entire screen
      How to move the cursor to a particular row and column position,
         given the current row and column position
      How to clear the portion of the current line under and to the
         right of the cursor (clear-to-end-of-line); not required,
         but desirable from a performance standpoint
      Whether your terminal "wraps around" to the next line when a
         character is placed in the last column of a line
      How to insert a blank line and slide the line under the
         cursor and subsequent lines down (not required but desirable)
      How to delete the line under the cursor (not required, but
         desirable)


To add a new terminal type:

      Make sure there is an entry in =extra=/ttypes for the terminal
         type being added.  The Subsystem Manager's Guide describes
         the form of entries in =extra=/ttypes.
      Add a macro definition for your terminal at the end of the
         "terminal types" section of the file '=src=/spc/se.u/se_def.i'
      Modify '=src=/spc/se.u/source/setscreen.r' to include the number
         of rows and columns displayed on your terminal
      Add the name and type of your terminal to the string_table in
         '=src=/spc/se.u/source/decode_mnemonic.r'.  (Note that this
         table is sorted alphabetically by terminal name.  Also note
         that the name you place in the string_table should be the
         same as the name used in =extra=/ttypes.)
      Modify the usage message in '=src=/spc/se.u/source/usage.r' to
         include the new terminal type
      Add code to '=src=/spc/se.u/source/position_cursor.r' to move
         the cursor to a given row and column on the screen (normally
         done by adding a subroutine call to a new subroutine created
         especially for the new terminal type)
      Add code to '=src=/spc/se.u/source/clear_to_eol.r' to handle the
         clear-to-end-of-line function; this can be simulated if your
         terminal does not have hardware assistance for clear-eol.
      If your terminal does not wrap around to the next line when you
         place a character in the last column of a line, you must add
         code to '=src=/spc/se.u/source/send.r'
      Add code to '=src=/spc/se.u/source/clrscreen.r' to home the cursor
         and clear the screen.
      Add code to '=src=/spc/se.u/source/hwinsdel.r' to return YES if
         your terminal has hardware line insert/delete
      Add code to '=src=/spc/se.u/source/inslines.r' to output the
         line insert sequence for your terminal if your terminal
         has this feature.  Be sure to set 'delay' to the number
         of milliseconds your terminal must have to perform a
         line insertion.
      Add code to '=src=/spc/se.u/source/dellines.r' to output the
         line delete sequence for your terminal if it has this
         feature.  Be sure to set 'delay' to the number
         of milliseconds your terminal must have to perform a
         line deletion.


Note that if you add any subprograms to 'se', you should include their
names in the linkage statement in file 'se_link.i'.  It is also
necessary to put an 'include' statement for each new subprogram
into the appropriate 'se_mod?.r' file (where ? is 1, 2, 3, 4, 5, 6, 7 or 8).
Module 7 seems to be a popular place to add cursor positioning routines.


Attach to the directory '=src=/spc/se.u' and enter the commands

     echo 4000 >segment
     build

to build a test version of the editor in the file 'se' (in the current
directory).

Once you have verified that your changes work, a production version
of the editor may be built by entering the following commands (while
still attached to the directory '=src=/spc/se.u'):

     echo 2031 >segment
     sep se -link

The shared portion of the editor will be stored in the file 'se2031'
and the executable part in the file 'se'.  To install the new version,
make sure that the current version is not in use and then give the
following commands:

   cp se =bin=
   chat =bin=/se
   cp se2031 =system=

Then, give the following commands from the system console:

   opr 1
   share system>se2031 2031 700
   opr 0

If you feel adventurous, you can create a file for the new
terminal in =vth= also.