Epson LQ-950 User Manual - Page 132

Pin labels To tell the printer which pins to fire in each column, you first divide each of the vertical columns into three sections of eight pins each and consider each section separately. Since there are 256 possible combinations of the eight pins in each section, you need a numbering system that allows you to use a single number to specify which of the 256 possible patterns you want. This numbering system is shown below: 126 64 32 16 : 2 1 To fire any one pin, you send its number to the printer. To fire more than one pin at the same time, add up the numbers of the pins and send the total. Using these labels for the pins, you fire the top pin by sending 128. To fire the bottom pin, you send 1. If you want to fire only the top and bottom pins, you simply add 128 and 1, and send 129. 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. Software and Graphics 4-13