Table of Contents
Advertisement
76
90 LPRINT CHR$(24);
I
100 LPRINT "DOES NOT WORK"
Here is what this program will print:
BACKSPACE
DOES NM
WORK
DELETE
DOES
WORK
DOES NOT WORK
The backspace
codes in line 30 move the printhead
a total of
three spaces to the left so that the first part of line 40 will over-
print the word "NOT". The delete codes in line 60 "erase" the
three letters in the word "NOT" so that it doesn't even print.
In line 90, CHR$(24) deletes
the words
in line 80. The
semicolon at the end of line 80 prevents a line feed from causing
that line to print before the printer receives the CHR$(24) code.
The text in line 100 prints as it normally would because it is
after CHR$(24).
n Immediate-print
This printer can print at fine rate of 250 characters
per sec-
ond. But it will also print more slowly at the speed of your typ-
ing. In immediate-$rint
mode, the printhead prints one character
at a time, as you send it. This printer also moves the paper up so
that you can see the current
line and then down to continue
printing.
You can turn immediate-print
mode on with (ESC) "i" 1. But
before looking at it, let's review the normal operation
of the
print buffer. Enter this program.
20 A$="" :INPLJT w TYPE A CHARACTER ",A$
30 IF A$="" THEN 50
40 LPRINT A$; : GOT0 20
50 LPRINT : LPRINT CHR$(27);"@"
Now type
several
characters,
and after
each press
the
RETURN
key.
True
to form,
the printer
just
stuffs
the
characters
into its buffer while it waits for a carriage return
code. (In this program
the RETURN
key doesn't send a car-
Advertisement
Table of Contents
