IBM Personal Computer AT Manual To Operations page 209

DC3 Deselect Printer
DC4
ESC
ESC A
Sets the Color Printer so as not to accept
data from the system unit. A printer must
be initialized by the system or control panel
buttons or selected using DC 1 (Select
Printer) to accept data.
LPRINT CHR$(l9);
Cancel Double-Width Printing by Line
Ends double-width printing by line which
was started by SO.
LPRINT CHR$(20);
Command Prefix
Sets the printer to accept the next data sent
as a printer command. (See the following
list. )
LPRINT CHR$(27);
Store Text Line Spacing
Format: ESC A;n;
ESC A stores a line-feed value of n/72
inch. ESC 2 (Start Text Line Spacing) must
then be sent before the line spacing will
change. For example, to store a line-feed
value of 24/72 inch, the code is ESC A 24.
However, until ESC 2 is sent, any text
following the ESC A 24 will space at the
previously set line-feed increment. The text
following the ESC 2 will be printed with a
new line-feed increment of 24/72 inch.
Any increment between 1/72 and 85/72
may be used.
LPRINT CHR$(27);CHR$(65);CHR$(n);
Color Printer 1-99