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PRINTING FROM BASIC
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Unlike many other forms of BASIC, neither APPLESOFT nor
INTEGER BASIC has any special command to print exclusively on
the printer. The two most commonly used commands to send data to
the printer instead of the screen are LPRINT and PRINT# file or device
number. Similarly, the command LUST is often used to list programs
on the printer. The examples in Epson manuals are written in standard
MICROSOFT BASIC, which uses the commands LPRINT and LUST.
Because these commands are not available in either APPLESOFT or
INTEGER BASIC, other methods have to be used to get the same
effect.
The interface card is a means of sending characters to a device
other than the screen, and you can use it just like any other card which
processes data. The card is made active by giving the command PR#
followed
by the slot number of the card, and deactivated with PR# 0.
For example, initialising the card using PR # 1 simply tells the APPLE
to route information through the card in slot I.
LISTING 1D THE PRINTER
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If
you have typed PR # 1 at the prompt, anything more that you type
on the keyboard will be sent to the printer, but, because of the way
printers work, it will only be printed out when you press the
I
R�TURN
I
key. The cursor will appear at the beginning of the line on
which the PR# 1 was typed and you will have to type without seeing
anything happen.
The interface lets you overcome this by using the <CTRL>-11
command to echo all characters to the screen. For example, giving the
<CTRL>-11 command then typing HOME will clear the screen as
normal, and the word 'HOME' will also appear on the printer when
the
I
RETURN
I
key is pressed. Similarly, if you use the LIST command,
not only will the printer list the program, but it will also print the word
'LIST' above the listing just as it would appear on the screen.
Listings made in this way appear on the screen at the same time as
they are being printed. The printer gives a listing which will have the
program lines printed on separate lines of the paper rather than split as
53
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