Atari 400

Atari BASIC Reference Guide 149
optional filename extension. The filename extension must be
separated from the filename by a period.
The following examples are correct OPEN statements for a disk.
Printer
EXAMPLE
OPEN #1 , 4, 0, "D2:GRADES.BAS"
OPEN
#3, 12 , 0, "D:JONES"
An I/ O channel for the printer can be for output only. The
printer must be turned on before the OPEN statement is
executed. If the printer is used with the Atari 850 interface, this
also must be ready to operate. The printer must be in the Online
mode if it has Local/ Online switch.
The
third argument of an OPEN statement for the printer is
generally O. However , the Atari 820 printer outputs sideways
characters
if the third argument is 83 .
Editor
An OPEN statement for the editor allows the screen and
keyboard
to be used for input and output. When an OPEN
statement is executed for the editor, the display resumes
graphics
mode 0, the screen is cleared, the cursor is reset, and
the
color registers are set to the default values.
The editor can be used in one of three modes. The mode is
determined by the second argument of the OPEN statement
(Table 5-1). The display is always used for output, but the display
or the keyboard can be used for input.
The third argument of an OPEN statement for the editor is
ignored. Even though this value has no effect, it must always be
included in the OPEN statement.