The fictive printer emulated by textprinter can print in landscape mode, set the character size, print bold, underlined and/or italic text. And (a feature that no real printer had) it can print pictures from a .jpg file.
A control sequence is always started by ESC, in Python code you would write "\033" or "\x1b".
|ESC "c12" SPC||select 12 cpi|
|ESC "b1"||activate bold font|
|ESC "b0"||deactivate bold font|
|ESC "i1"||activate italic font|
|ESC "i0"||deactivate italic font|
|ESC "u1"||activate underlined font|
|ESC "u0"||deactivate underlined font|
ESC means : a byte of value 0x1B (Escape)
SPC means : a byte of value 0x20 (Space)
See also: Examples of textprinter input files are