Epson LX-810 User Manual page 105

Pin labels
To tell the printer which pins to fire in each column, you need a
numbering system that separately identifies each of the eight pins
as shown below. This system allows you to specify all 256 possible
pin combinations with a single number.
To fire any one pin, you just 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 the pin labels shown above, 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 certain 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. Before you can use these numbers in a graphics
program, however, you need to know the format of the graphics
command.
128
2
1 I
Software and Graphics
Graphics
4-11