Display double width and double height text.
Sets a per line attribute that allows displaying double height text. For proper text display two lines with identical text content need to be output. The first line needs to be set with set double height line top half and the second line needs to be set with this control.
If the line mode is switched from single width to this mode, the number of columns is halved. If the cursor was in the second half of the row, the cursor is moved to the new right-most column. The columns no longer visible keep their contents and are revealed when set single width line is set for the line.
In left and right margin mode this control is ignored.
Seems not to work with some fonts
Konsole threats this control and set double height line top half identical. Konsole draws the first line with this per line attribute as double height and then unconditionally skips the next line.
Interaction with view-port scrolling is erratic.