Now RUN it. You should hear a short beep. (If you don’t hear it, check DIP switch 2-2, using the procedure we gave in Chapter 1.) That’s the printer’s beeper, which most often sounds to inform you that you’ve run out of paper (Appendix F lists other causes of beep- ing). When you produce the beep, you’ve proved that on your computer certain codes do indeed perform printer functions. Table 2-3 shows the ranges that the FX uses when it interprets ASCII codes for characters and functions.

 

Table 2-3. ASCII codes on the FX

 

 

 

ASCII code

 

FX interpretation
group

 

 

Ø to 31, 127

 

Printer control codes

32 to 126

 

Standard (Roman) character set

 

128 to 159, 255

 

Additional control codes (Function same as Ø-31, 127)

16Ø to 254

 

Italic character set

See either Appendix A or the Quick Reference Card for a chart of the FX interpretation of each ASCII code number.

This would be a good time to try printing a few of these codes on your own. And you may want to take a break before you start the next section.

Escape-CHR$(27)-and other CHR$ commands

As more features are added to the printer, even the extended range of codes (0 - 255) is inadequate if only single-code CHR$ instructions can be used. Because of this, Epson has designed the FX printer’s logic to understand special sequences of control codes, the ESCape code sequences. You use these code sequences to select one or more printing features, or modes.

Such modes as Italic Mode and Expanded Mode affect the way the characters look. Other modes affect spacing and therefore the formatting of your pages. Appendix C, which is reprinted on the Quick Reference Card, collects the modes into categories for quick reference.

Each ESCape code sequence consists of the ESCape code, which is CHR$(27), plus one or more of the FX’s other CHR$ control codes.

42