Chapter 7
If we really understand what we’re doing, the 7-bit limitation can be overcome.
Apple users try:
140 GOSUB 20 : GOSUB 20 : PRINT
150 DATA 23,-23,127,127,-127,127
and RUN.
Now we are getting somewhere. Instead of trying to print the entire line in one
shot, we hooked two print routines together with a semicolon. The first printed
23 columns, and the second printed 127 columns.
Really Long Lines
Suppose we want to use even longer lines, up to the maximum of 480 columns.
To specify a line length greater than 255, the last number in the <ESC>“K” Nl
N2 sequence must be a 1. Instead of changing line 30, we can accommodate the
entire range of line widths by adding:
25 IF N>255 THEN PRINT CHR$ (27) "K" CHR$ (N-256) CHR$ (l);
: GOT0 40
If the desired line width (N) is greater than 255, CHR$ (1) adds 256 columns, and
CHR$ (N-256) takes care of the difference. Let’s test this upgrade by changing:
10 PRINT CHR$ (27) "A" CHR$ (7)
140 GOSUB 20 : PRINT
150 DATA 300,-300,127
and RUN.
Figure 7-6
We don’t have to count the dots to check it. There are 60 dots per inch, so the
line should be 5 inches long.
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