The printer can underline all characters (including right- and left-side character
spacing), but cannot underline the space set by HT and 90° clockwise-rotated
characters.
After the underline mode for Korean characters is turned off by setting n to 0,
underline printing is no longer executed, but the previously specified underline
thickness is not changed. The default underline thickness is 1 dot.
The specified line thickness does not change even when the character size
changes.
It is possible to turn underline mode on or off using FS !, and the last received
command is effective.
When the slip paper is selected, the underline thickness is 1 dot even if n is 2 or
50.
The ranges of c1 and c2 differ, depending on models and the character code
system used. The ranges of c1 and c2 for each model are as follows.
Cancel the user-defined Chinese characters, character codes are specified by c1
and c2.
c1 specifies the first byte of a character code for a user-defined Chinese
character.
c2 specifies the second byte of a character code for a user-defined Chinese
character.