Epson 8900 Series - Manual (Page 164)

Epson FX Printer Emulation Mode 8-12
Cancel Most Significant Bit Control
Escape sequence: ESC #
Hexadecimal: 1B 23
This command cancels printer control of the received character MSB
and returns control to the computer. This enables the computer to
select characters from either the GL half or the GR half of the
selected printer character set.
Select Unidirectional Printing for One Line Only
Escape sequence: ESC <
Hexadecimal: 1B 3C
This command selects unidirectional printing for one line only. Upon
receiving this command, the printer moves its printhead to the left
margin and begins printing. A CR control character cancels this
command and returns the printer to the bidirectional print mode.
Select Unidirectional Printing
Escape sequence: ESC U SOH
Hexadecimal: 1B 55 01
This command selects unidirectional printing. Upon receiving this
command, the printer moves its printhead to the left margin and
begins printing.
Cancel Unidirectional Printing
Escape sequence: ESC U NUL
Hexadecimal: 1B 55 00
This command cancels the unidirectional print mode selected by the
Select Unidirectional Printing command and returns the printer to
normal bidirectional printing.