prints dots in only half the possible dot positions in any one row. The higher density means that the resolution of the pattern is better than in single-density mode. When you design patterns in these two modes, however, you must make sure that no dots overlap.

Reassigning a graphics mode

Another graphics command lets you assign a different eight-pin graphics mode to one of the specific eight-pin graphics commands. You can use this command with graphics software programs to quickly change the density and proportions of your printouts. Changing the graphics option changes the width without changing the height.

The command for reassigning a graphics mode is ESC ? c m. In this command, c is a letter designating one of the four alternate graphics codes (K, L, Y, or Z) and m is the mode number of the new mode, as listed in the table on page 4-15.

For example, to change the ESC K command to select the CRT I screen graphics mode, the command in BASIC is’ the following:

LPRINTCHR$(27);"?K";CHR$(4);

A little experimentation should tell you whether the reassigning command can improve your graphics printouts.

Designing your own graphics

This section takes you through the development of a graphics program. The example is not especially complicated, but it does include the same steps you would use for a more complex figure.

You should plan your figure with dots on graph paper, but before beginning to place the dots, you must decide which graphics density you want. The figure on the next page shows the differences between three common modes.

4-16

Using Software and Graphics