128

64

32

16

8

4

2

1

not used

0

0

0

0

0

0

0

0

0

Figure 9-1. Pin labels

To fire any one pin, you send its number. To fire more than one pin at the same time, add up the numbers of the pins and send the sum to the printer. With these labels for the pins, you fire the top pin by sending 128. To fire the bottom graphics pin, you send 1. If you want to fire only the top and bottom pins, you simply add 128 and 1, then send 129.

By adding the appropriate label numbers together, you can fire any combination of pins you want. Figure 9-2shows you three examples of how to calculate the number that will fire a particular pattern of pins.

 

 

 

 

 

 

\

 

 

 

128

s

128

 

‘28

01

 

 

128

 

0

 

 

 

 

 

 

 

 

64

 

 

 

 

64

 

64

 

64

 

 

 

 

 

 

 

 

32

0

 

 

 

 

 

 

 

 

32

16

a

16

 

 

 

 

 

16

8

0

 

 

 

 

 

 

8

 

8

4

0

2

 

 

 

 

 

4

2

a

 

 

 

2

 

2

1

a

 

id

 

 

 

7r

 

1

not used

0

 

 

 

 

 

not used

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

0

0

• 0 0 0

4

1

5

J

Figure 9-2. Calculating numbers for pin patterns

77