Some computer systems change one or more codes when sending them from BASIC to the printer. The ability of the Apex80 to dump in hexadecimal lets you determine which codes are creating problems for your system.

A hex printout of a program shows you exactly what the printer is receiving, regardless of what the computer is sending. The following test program lets you check to see which codes, if any, are problems for your computer system.

10 FOR X=0 TO 255

20 LPRINT CHR$(X);

30 NEXT X

Put the printer in data dump mode and then run the program. Remember to press the ON/OFF LINE button to make the Apex80 print

the final line. Then compare your printout with the list of hex codes in order in Appendix B. If any are skipped or repeated, you know that your BASIC language changes some codes before it sends them to the printer.

For example, the line below is the first line of the printout of the test program run on a system that changes hex 09, which is the code for horizontal tabbing, to several 20s, the code for a space. Therefore, you know that if you use this system, you must be careful about sending a decimal 9 (hex 09).

0000

00

01

02

03

04

05

06

07

08

20

20

20

20

20

20

20 . . . . . . . . . .

The data dumping capability can help you solve problems quickly. Appendix B can help you translate the hex codes to ASCII equivalents.

Coding Solutions

Once you’ve determined that a code creates problems for your printing, either by trial and error or by using the data dumping capability of the Apex80, you can start overcoming them.

Because each computer system deals with ASCII codes differently, it is impossible to provide solutions for all potential problems in one appendix. It may help, however, to be aware of some generic problems and some ways to handle them.

C-6

Problem Solving and Maintenance