5.The last important thing to do is to reset the printer to its default settings, including the normal line spacing (line 180).

Notice that the graphics command (ESC K) can be in effect for only one print line. To print more than one line of graphics, the graphics command must be issued before each line.

Density varieties

Although all the examples so far in this section have been in the single- density graphics mode, there are seven other eight-pin densities and two that use all nine pins.

Nine-pin graphics is not necessary for most uses, but you can find the command (ESC *) in the Command Summary in Chapter 8. The four most common eight-pin modes are ESC K, ESC L, ESC Y, and ESC Z. There is also a general purpose command for any of the eight-pin graphics modes: ESC *. This command is used in the same way as the individual commands, except that before n1 and n2 you must send the code for the graphics mode required.

The different graphics modes are summarized in the following table:

 

 

Alternate

 

 

Horiz. density

 

Option

 

Code

m

 

(dots/in.)

 

 

 

 

 

 

Single-density

1

ESC K

0

1

60

 

 

I

 

Double-density

1

ESC I

1

I

120

 

 

High-speed double-density*

 

ESC Y

2

 

120

 

 

Quadruple-density*

 

ESC Z

3

 

240

 

 

CRT I

 

none

4

 

80

 

 

Plotter (1:1)

 

none

5

 

72

 

 

CRT II

 

none

6

 

90

 

 

 

 

 

 

Double-density plotter

 

none

7

 

144

 

 

*Adjacent dots cannot be printed in this mode.

Modes 4, 5, 6, and 7 are special modes that alter the horizontal density to give the proportions of a computer monitor (the CRT modes) or to match the vertical density so as to give round circles (the plotter mode).

In two modes, high-speed double-density and quadruple-density, the print head cannot print two consecutive dots with the same pin, so it

Using Software and Graphics

4-15