SCS

The SNA character string (SCS) has a relatively simple structure, consisting of a 1-byte hexadecimal control code followed by the data to be printed. Multiple control codes can be inserted into SCS by printing applications in order to achieve certain types of output. The SNA character string is sent to the printer in physical blocks of 256 bytes.

The following are a few examples of SCS control codes:

Hex	Description	Code
03	ASCII transparent data	(TRNA)
05	Horizontal tab	(HT)
0B	Vertical tab	(VT)
0C	Forms feed	(FF)
0D	Carriage return	(CR)
1A	Unit backspace	(UBS)
15	New line	(NL)
16	Backspace	(BS)
35	Transparent	(TRN)
2843	Set attribute	(SA)
2BC1	Set horizontal format	(SHF)
2BC2	Set vertical format	(SVF)
2BC6	Set line density	(SLD)
2BD2	Set presentation page size	(SPPS)
2BD4	Begin underscore	(BUS)
2BFE	Load alternate character	(LAC)

How print attributes are accomplished by SCS

The following examples show how common print functions can be accomplished by printing applications using SCS.

Line spacing: The equivalent number of NL (new line) control codes is inserted.
Underlining: The underlined text is first inserted into SCS, followed by the appropriate number of BS (backspace) control codes, and then the same number of underscores.
Overstriking: This is similar to underlining, except that the overstrike characters are used instead of the underscore.
Emphasis: The text to be emphasized is put into SCS, followed by the necessary number of BS (backspace) control codes and then the emphasized text is repeated. This sequence could be repeated several times.
Page eject: The FF (forms feed) control code is inserted.
Font changes: Font changes are supported by printers such as the 5219 that support final-form text (FFT).