Chapter 11

Varieties of Graphics Density

We introduced you to FX graphics by having you use Single- Density Graphics Mode and a single pin per column. In this chapter we cover six more graphics densities and provide examples of designs that use pin combinations. We also offer you several tips for programming graphics.

Graphics Programming Tips

Let’s start with a program that fires the four low graphics pins in each column. Since these pins are labelled 1,2,4, and 8, and since the sum of these four labels is 15, send a CHRS(15) to the printer:

NEW

20 A$=CHR$(27)+"K"+CHR$(100)+CHR$(0)30 B$=CHR$(l5)
40 LPRINT A$;: FOR X=1 TO 100: LPRINT B$;: NEXT X 80 LPRINT CHR$(27)"@"
Sure enough, CHR$(15) fires the four low pins.

This is basically the same program as the.one you used to print the first slash in the last chapter, but we‘ve added a new wrinkle. We have you store the concatenated string for entering Single-Density Graphics Mode in the variable A!$ and the string for data in B$. The first variable makes it easy to enter a Graphics Mode several times in one program, and the second, to send data repeatedly.

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