Epson LQ-860 User Manual - Page 118

By adding the appropriate label numbers together, you can fire any combination of pins. Below are three examples of how to calculate the number that will fire a particular pattern of pins. With this numbering system, any combination of the eight pins adds up to a decimal number between 0 and 255, and no numbers are duplicated. Because there are 24 pins in each column, you must make a calculation for each of the three sections in each column. As you can see, this method of planning and printing dot graphics requires considerable calculation. Because triple-density uses 180 columns per inch, printing a single line of triple-density graphics only one inch long requires 540 numbers. Fortunately, commercial graphics software is available to do these calculations for you. Before you can put these numbers into a graphics program, however, you need to know the format of the graphics command. The Graphics Command The graphics mode command is quite different from the other commands used by the printer. For most of the other printer modes, such as emphasized and double-wide, one command turns the mode on and another turns it off. For graphics, the command is more complicated because the code that turns on a graphics mode also specifies how many columns it will use. After the printer receives this code, it interprets the numbers that follow as pin patterns and prints them on the paper. Software and Graphics 4-11