Line 20 begins a loop to produce multiple print lines. Lines 30 and 40 were covered above, but an LPRINT is added to line 50 to produce a line feed after line 40. Lines 60 and 70 are like lines 30 and 40 except that lint! 70 uses a reversal of the patterns in line 40. As the loop is executed, the program prints lines 40 and 70 alternately so that the patterns of the print lines will fit together well.

Notice that the graphics command can be in effect for only one print line. The command is in lines 30 and 60 so that it is issued each time a new print line is begun. You cannot print more than one line of graphics without having the graphics command issued more than once.

Line 90 is the reset code to return the printer to its defaults.

Density Varieties

Although all the examples so far in this chapter have been in the single-density graphics mode, the LX-86offers five other eight-pin density modes and two nine-pin ones. Nine-pin graphics is not necessary for most uses, but you can find its command (Escape “ ^ “) in Appendix C. All the eight-pin densities and their commands are

described in Table 9-l.

Table 9-l. Graphics modes

Mode

Density

A l t e r n a t e

Description

code

 

 

 

 

 

 

 

0

Single

ESC "K"

60 dots/inch:

 

 

 

480 dots/8" line

1

Low-Speed

ESC "L"

120 dots/inch

 

Double

 

960 dots/8 line

2

High-Speed

ESC "Y"

120 dot positions/inch

 

Double

 

Faster than Mode 1; does not print

 

 

 

consecutive dots in a row.

3

Quadruple

ESC "Z"

240 dot positions/inch; 1920 dot

 

 

 

positions/8" line. Does not print

 

 

 

consecutive dots in a row.

4

CRT

none

80 dots/inch;

 

 

 

640 dots/8" line

5

One-to-one

none

72 dots/inch;

 

(plotter)

 

576 dots/8" line

 

 

 

Produces the same density hori-

 

 

 

zontally as vertically, which makes

 

 

 

circles look round.

6

90 dots/inch

none

90 dots/inch;

 

 

 

720 dots/8" line

78