Epson PR9 User Manual page 174

ESC $ @
This command code sets printer working mode to CHINA mode.
Hex (1B 24 40)H
Decimal (27 36 64)D
Octal (33 44 100)O
Code ESC ( H and ESC k can change this working mode. In this mode all characters,
except single byte command codes, will be regarded as two byte code.
ESC , n
This command code can set or reset CHANGCHUN condensed mode
Hex (1B 2C n)H
Decimal (27 44 n)D
Octal (33 54 n)O
n = 2 : Sets CHANGCHUN condensed mode compress proportion: 70%.
n = 1 : Resets CHANGCHUN condensed mode.
Appendix B OKI-Emulation Commands
Set / Reset CHANGCHUN Condensed Mode
Set CHINA Mode
B-27