Figure
17-1.
Barchart
In line 130 the parameters for “&” specify that our 14 user-defined
characters will be stored at positions
94
to
107
(ASCII symbols ^ to k).
Line 140 sets up a READ loop (Y) for the characters and sends the
attribute byte—CHRS(139). Line 160 closes the loop and sets the form
length to 33 lines so that, while you are setting the chart up, you can
print two charts to a page. When you finish making experimental
printouts, you will probably want to change this specification to 66 to
conform to the usual page size. Check that you like the positioning of
your paper since “C” also sets top of form to the current position of
the print head. Now add these lines:
10 FOR J=1 TO
3:
FOR K=1 TO
3
20
READ MAX(J,K)
30
NEXT K:
NEXT
J
40
DATA 12,18,23,28,36,34,28,27,30
Line
20
READ
S
the maximum heights for the chart’s vertical bars
from line
40
and stores them in the array MAX. The next data lines
define three new characters:
70 DATA 2,1,64,32,16,8,4,2,1,64,32
80 DATA 127,0,99,0,65,0,65,0,99,0,127
90 DATA 127,0,28,0,62,65,62,0,28,0,127
228
