IBM 5150 Hardware Reference Manual page 99

Note: The form length of 72 lines per page is applicable to only
the version marked with identifier code "M72" on the
rear side of the lower case of the Printer.
This code always initializes the printing of the data stored in
the print buffer.
(5) SO (Shift Out)
Whell the SO code is input, all data that follows it in the same
line
will
be printed out in enlarged (double width) characters.
This code is cancelled by the printing operation or the input of
"DC 4" code and can be input at any column position on a line.
Therefore, normal size and enlarged characters can be mixed
on the same line.
1. [DATA]
ABC 1
so
1 DEF 1DC41 GHI
~
[!;£J
[PRINT] ABCDEFGHI
2. [DATA
ABCD
~
EFGH
~ ~
IJLK 1SO 1 MNOP
~ ~
[PRINT ABCDEFGH
IJKLMNOP
(6) SI (Shift In)
When the SI code is input, all data that follows it will be printed
out in condensed characters. This code is cancelled by the input
1""""\
of "DC 2" code. The SI code can be input at any column
position on a line, but all characters/symbols on the line
containing SI code are printed out in condensed characters.
When printing condensed characters, the data capacity of the
print buffer will become 132 columns per line.
When the SO code is received after the input of the SI code,
condensed enlarged characters (double width of condensed
characters) can be printed. This condition is cancelled by
"DC 4" code, and the character size returns to "condensed".
1. [DATA]
~
ABCDEFGHIJKL
~ ~
[PRINT] ABCDEFGHIJKL
2. [DATA] ABC
@]
DEF
~
GHIJKL
~ ~
[PRINT] ABCDEFGHIJKL
(7) DC 4 (Device Control 4)
The DC 4 code cancels the SO mode.
[DATA]
~
ABCDEF
~
GHI 1DC 41 JKL
~ ~
[PRINT] ABCDEFGHIJKL
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