Escape sequences
Although there are more than 30 control codes available to control the operation of your printer, many more codes are required to run today’s sophisticated printers. Therefore, ASCII codes are grouped in sequences that represent certain functions. These code sequences make use of the ASCII codes with decimal values of 32 through 255, normally reserved for characters and punctuation, to control printer functions. This is done by first sending a standard code to tell the printer that the codes that follow are to be used as control codes, not as characters or punctuation.
The standard code that is sent at the beginning of these code sequences is the Escape code, decimal value 27. Any sequence of codes starting with the Escape code is called an Escape sequence. You will probably see Escape written in different
Printer commands
In order for the printer to recognize the instructions it receives, ASCII codes must be sent to the printer within a specific format, called a command. An Escape sequence is a command, as is any ASCII code or sequence of codes that instructs the printer to carry out a particular function. Your software continually sends commands to your printer and your computer screen. These commands instruct your printer to perform such functions as print in a particular typeface, feed the paper a certain amount after printing each line, and start printing on a particular spot on the page.
Some software programs let you send these commands yourself. The commands that your printer recognizes are listed in the Command Summary, Chapter 8, and on the Quick Reference card in the back of this manual.
Getting the Most from Your Printer |