User`s manual

IBM 5250 CONTROL CODES
AXIS AX-3 Cobra+ Technical Reference 28
Begin Underscore (BUS)
Activates the underscore function.
Count (nn): Number of bytes following this command plus one.
Bypass (bp): Valid values are:
End Underscore (EUS)
Deactivates the underscore function.
Begin Overstrike (BOS)
Activates the overstrike function.
Count (nn): Number of bytes following this command plus one.
Character (ch): The character code to be used as the overstrike character.
Bypass (bp): Valid values are:
Graphic Character Set Global ID (gcgc): This two-byte value is ignored.
Code Page Global ID (cpcp): This two-byte value is ignored.
End Overstrike (EOS)
Deactivates the overstrike function.
Index Return (IRT)
Same as Required New Line (RNL).
$2B $D4 nn $0A $01 bp
Value Description
$00 Underscore all graphic characters
$80 Underscore all graphic characters except space and
relative horizontal positioning control
$2B $D4 $02 $0E
$2B $D4 nn $72 ch bp gcgc cpcp
Value Description
$00 Overstrike all graphic characters
$80 Overstrike all graphic characters except space and relative
horizontal positioning control
Other Identifies the graphic character not to be overstruck
$2B $D4 $02 $76
$33