A very few pin patterns are needed for this program. In fact, each “pattern” consists of only one pin, making the numbers easy to calculate:

1

for the low pin

64

for the high pin

1, 2, 4, 8, 16, 32, 64 for the diagonal rise 64, 32, 16, 8, 4, 2, 1 for the diagonal fall

As you will see in the next few pages, these pin patterns are coded right into the program. You’ll only need to store as data the number of repetitions for the low and high sections.

A close look at Figure 12-4reveals that most of the lines can be produced by repeating a d-step pattern:

1.Fire the bottom pin (pin 1), repeat L times.
2.Draw a diagonal rise (pins 1 - 64).
3.Fire the top pin (pin 64), repeat H times.
4.Draw a diagonal fall (pins 64 - 1).

This pattern is repeated several times. Printing the figure is mainly a matter of reading the length of the low and high sections, then printing the four-part cycle.

First version of 3D program

We have you enter this program in portions that are easy to discuss as units, so please don’t try to RUN it until we give the word.

Might as well start off with the easy stuff. Set the line spacing for 7- pin graphics:

NEW

l0 LPRINT CHR$(27)"1"

Note: If your system leaves gaps in 7-dot graphics printing, you will prefer to use the 6-2/3-dotline spacing, CHR$(27) “3’CHR$(20).

Next up are the three straight lines at the start of the design. There’s no need for anything fancy-just a single dot printed across the page. For that, add these lines (lines 20 and 170 are different for the FX-100):

29 G$=CHR$(27)+"L"+CHR$(51)+CHR$(3): GOSUB 160
158 LPRINT CHR$(27)"@": END160 FOR X=1 TO 3: LPRINT G$;

165