Page 4-19CHAPTER 4 — PROGRAMMABLE FUNCTION STRINGS
BSBOLD1 and BSBOLD2
Backspace bold. These PFSs are sent to the printer in response to an SCS
Begin Emphasis command, or when a character-Backspace-same
character sequence or a text-Carriage Return-same text sequence is
detected in the data stream. The BSBOLD1> and BSBOLD2> PFSs are
used only for printers that are otherwise incapable of bold printing. If the
BOLDTYP= option (under FMTINFO: for the output port) is set to BACK
SPC, the OPTIMA will perform the following sequence of operation for
each character that is to be printed bold.
1) The character to be printed bold is sent to the printer to be struck
the first time.
2) The BSBOLD1> PFS is sent to the printer. It should backspace one
character, then perform a small offset to the right. The small offset
is so that the first and second striking of the character are not
directly on top of each other  which would not perform bolding
on laser printers.
3) The character is sent a second time.
4) The BSBOLD2> PFS is sent to the printer. It should perform a small
offset to the left of the same distance that the BSBOLD1> PFS offset
to the right. This will place the print position at the printer at the
same place it was before step 2.
UNDL ON
If UNDLSPC has been set to UNDERLIN in the FMTINFO menu, this
PFS will be sent to the printer to turn on underline mode. This can be the
result of a direct System request for underlined text as a response either to
an SCS Word Underscore command or an SCS Begin Underscore
command, or if the System sends Underscore characters in a second pass
through the line (with a character-Backspace-Underscore sequence or a
text-Carriage Return-Underscore sequence).