The second approach is to use commercially available software that is specifically designed to overcome these coding problems. Consult your computer dealer or computer publications to see if a program for your computer system is available.

The third approach consists of avoiding the software that is changing the codes. On most computers you can send each code directly to the printer port. This bypasses the BASIC interpreter and avoids the interface.

Unfortunately, this process is also different for each computer system. Consult your computer’s manual to determine if you can do the same on your system.

A fourth approach is to change the printer driver program in your system. This requires a knowledge of machine language and of the way your computer works. If you don’t have this knowledge, your computer dealer may be able to help you or suggest someone who can.

Solutions for Specific Systems

The next four subsections illustrate dealing with interface puzzles on four types of computers.

Applesoft BASIC solutions

Applesoft BASIC does not use PRINT to send data to the screen and LPRINT to send data to the printer as MBASIC does. Therefore, put an PR#l at the beginning of a program and change all instances of LPRINT to PRINT.

If one of our programs contains an INPUT statement or a PRINT statement, there will be a message that should go to the screen before anything is sent to the printer. In these programs, leave the first lines as they are and after the INPUT and/or PRINT statements, add a line that states PR#l ; then change all the instances of LPRINT to PRINT and put a line that states PR#0 at the end of the program.

Apple® II solutions

There are two types of problems that you who own Apple II computers will need to address. The first is that the Apple II is an 8-bit computer, but its printer interface only handles seven bits. The second is that there is one problem code number: nine.

F-6