Star Micronics NX-10 user manual Next ANG% Return

660 RANG=ANG%*6 28/360

670 X2=RAD"COS(iANG)tlO : Y2=RADSSIN(RANG)tlO

680 GOSUB 250

690 NEXT ANG%

700 RETURN

If you are using with the IBM mode (DIP switch 1-6 off), change the following lines to the program given above.

140 LPRINT CHR$(27>;"A";CHR$(6);CHR$(27);"2"

230 LPRINT CHR$(27);"A";CHR$(l2);CHR$(27);"2'+

nHow the program works

In the program above, we’ve created an array called BIT%, which is dimensioned in line 40. You’ll note that instead of using numeric constants to dimension the array, we used the variables <MAXCOL% and MAXROW%. This way, if your computer has enough memory and you want to plot a larger image, all you need to change are the values in line 30. The array MASK% con- tains the values of the dots. (In order to make this program run on most computers, we’re only six pins for graphics. With many computers, you can use all eight available pins.) In lines 80 and

90 we’ve defined some other variables you’ll be interested in: LX, LXFAC, LY, and LYFAC are used as scaling factors. By changing these values, you can change the size of your printed image or even distort it (you can, for example, make our circle print as an ellipse). Experiment a little bit!

The main calculations for plotting the image are done in the subroutine starting at program line 600. This is where you put the formulas that you want to plot. By changing just the lines after 600 (with some creative mathematics!) you can plot any function - limited only by your imagination. Some examples are shown at the end of this section.

What the program section starting at line 600 actually does is