When the SQ-2000 produces 8-dot graphics options, it prints with every third nozzle.

Each byte of data received controls the nozzles for only one vertical column of dots. This means you have to send the printer more information when printing dot graphics, but it also means that you have full control over what each print nozzle is doing.

A byte of data contains eight binary digits, or bits. Each bit controls one of the eight nozzles used for 8-dot graphics. Figure 6-l shows how a graphics data byte controls eight print head nozzles.

Graphics

data byte

Most significant

Least significant

b i t

b i t

Print head dot nozzles

Figure 6-Z. Graphics data byte and print head nozzles

Creating binary bit patterns like this may be easy for compu- ters, but it’s difficult for humans. There is an easier way to create graphics data bytes. If you assign each of the print head nozzles a value, the value of a graphics data byte is the sum of the values of the nozzles that you want to print (see Figure 6-2).

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