SB-10 USER'S MANUAL

70 NEXT J
80 FOR J==6 TO 0 STEP -1
90 L-PRINT CHR$( 23);
100 NEXT .J
110 NEXT I
1 2 0 W I D T H "LPTI : " ,80
'1:I 0 I. P R 1 N T
:vivsli\~~w~w~~~~
Figure F-6. A zigzag pattern created with 8-bit graphics.
In line 30 of this program, we selected normal-density graphics
and indicated that 350 characters of graphics data would follow (94 _
+ (1 * 256) = 350). The loop between lines 40 and 110 is repeated
25 times; this is what gives us the zigzag effect. The loop from lines
50 to 70 creates the lines that slope up; the loop between lines 80
and 100 prints downward-sloping lines. This is an example of plotting
a very simple mathematical function to create a design.
Combining
text and graphics
It’s also possible to mix text and graphics in one line. This can
be useful for labeling charts and graphs, or even for inserting
graphics into text. Try adding these lines to the program:
25 LPRINT "WOW! " ;
115 LPRINT " THIS IS GREAT!";
If you run the program with these lines added, you should get a
printout that looks like this:
Figure F-7. Graphics pattern inserted within text.
There is one thing you must remember when you print this kind
of program: all graphics data must print on the same line. The
graphics command is turned off at the end of each line, even if you
have specified that more graphics codes will follow.
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• PRINTING A DESIGN OR GRAPHIC PICTURE
Since you control the firing of every pin, you can print nearly
anything that you can draw. In our next example, we’ll demonstrate
the printer’s ability to plot computer art of your own design.
The best way to start is to lay out your image on graph paper.
You can print eight rows (seven with a 7-bit interface) of dot columns
with each pass of the print head, so begin by drawing a heavy hor-
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