Additional Screen Functions

Several additional functions are available to manipulate the screen display. These should be included if the terminal supports these features. The functions are: insert-line (al), delete-line (dl), non-destructive-space (nd), backspace-cursor (bc), cursor-down (do), cursor-up (up), set-width-132 (W3) and set-width-80 (W8).

The four cursor movement commands are available to optimize cursor motion. The non-destructive-space function should move the cursor to the right one column; the backspace-cursor function should move the cursor left one column. Finally, the cursor-down function should move the cursor down one line and cursor-up should move it up one line. If omitted, cursor-down defaults to a line-feed character, and backspace-cursor defaults to a backspace character. There are no defaults for non-destructive-space and cursor-up.

The insert-line function should insert a blank line at the cursor line, moving the cursor line and all following lines downward. The delete-line function should delete the cursor line, moving all following lines up and inserting a blank line at the bottom of the screen.

NS should be added to the terminal database file entry for a terminal that does not scroll if the lower right corner of the screen is filled. This tells the ACUCOBOL-GT program that it is all right to use this position. NS is the complete sequence (... :NS: ...).

The set-width functions should change the display between 132-column mode and 80-column mode. Both must be specified to use this feature.

You can also specify when the cursor should be visible. These entries should handle cursor modification:

ve = set cursor to normal
vs = set cursor to bright
vi = set cursor to invisible

After vi has rendered the cursor invisible, ve is used to make it visible.

If your terminal does not have both a normal and a bright cursor, then set the ve entry to turn the cursor on and do not use the vs entry.

The VT-100 supports only one of these functions: Non-destructive-space. This is accomplished by sending ESC[C. Our current entry is now:

vt100|vt-100|DEC VT-100 :\