IBM Personal Computer AT Manual To Operations page 222

ESC SI Compressed Printing
Alternate command for SI.
LPRINT CHR$(27);CHR$(l5);
ESC SO Double-Width Printing by Line
Alternate command for SO.
LPRINT CHR$(27);CHR$(l4);
ESC T Cancel Subscript or Superscript
Ends subscript or superscript printing
started by ESC S.
Note: If ESC T is issued when not
printing in subscript or superscript, it is
acknowledged and ignored.
LPRINT CHR$(27);CHR$(84);
ESCU
Unidirectional Printing
Format: ESC U;n;
When n is 1, sets the printer to print from
left to right only. ESC U 0 returns the
printer to normal two-direction printing.
Unidirectional printing ensures a more
accurate printing start position for better
print quality.
Note: The Color Printer operates only
on the least significant bit of n.
Therefore, any odd-numbered ASCII
decimal value gives the same result as
n= 1, and any even-numbered ASCII
decimal value gives the same result as
n=O.
LPRINT CHR$(27);CHR$(85);CHR$(n);
1-112 Color Printer