Epson Apex-80 - Manual (Page 119)

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) ft a er each 80 characters you send it. Second, it adds
an LF to each CR in an LPRINT statement.
C-8
Problem Solving and Maintenance