Apple® II solutions

Apple II computers pose two types of problems. The first is that the Apple II is an 8-bit computer, but its printer interface handles only seven bits. The second is that there is one problem code number: nine.

The printer interface card furnished with the Apple II computer passes only seven bits to the Apex80, which means that you have a

7-bit system. Should you need an 8-bit system, the simplest solution is to purchase a new printer interface card from your dealer. Such a card is available for the Apple II.

The Apple II uses CHR$(9) to initialize the printer. This code and the following character or characters are intercepted by the printer interface card and used to change modes. You can divert all output to the printer instead of to the screen by sending the following line to the printer.

PR#l

PRINT CHR$(9)"80N"

Then type anything, followed by RETURN.

The CHR$(9)“80N” code directs all subsequent output to the printer, up to 80 characters per row. You can cancel this by typing:

PRINT CHR$(9)"I" or PR#0

The problem is that the Apex80 uses CHR$(9) to activate horizontal tabulation and can also use it in graphics programs. When you send this code, however, your system interprets it as a printer initialization code and the program does not work properly In these cases, use the following method to change your printer initialization code to a number that is not used in the program. For example, you can change your initialization code to one by typing:

PR#l

PRINT CHR$(9); CHR$(l)

IBM-PC solutions

There are two problems using the IBM Personal Computer BASIC to drive a printer. First, the IBM-PC BASIC inserts a carriage-return/ line-feed (CR-LF)after each 80 characters you send it. Second, it adds an LF to each CR in an LPRINT statement.

C-8

Problem Solving and Maintenance