Commodore 16 User Manual page 26

Now
add
the
other
letters'.
10
PRINT
"COMMODORE"
3.
YOU CAN ERASE CHARACTERS AND CLOSE
UP
SPACE
with
Ihe
DEL
Key
(gel
delete by pressing the INST/DEL key by
itself).
This
key erases characters
or spaces
immediately
to
the
LEFT
ol
the
cursor.
10
PRINT
"AFTERNOON SCHEDULE"
You can change
this lo
WEEKLY SCHEDULE
by moving
the
cursor
to
Ihe E
in
AFTERNOON,
pressing Ihe
msT/DFZ
key
three times,
and
typing
WHDO.Y
10
PRINT
"AFTERNOON
SCHEDULE"
and
press inst/del
three
times
10 PRINT
"QRNOON
SCHEDULE"
Type
in
WEEKLY
to replace
ERNOON
ann
(
i
return
4.
YOU CAN
RETYPE A
LINE
anytime,
even
after
you've
RUN
the pro-
gram Your Commodore
1
6 automatically
replaces
the old
line
with
Ihe
new one when
you press return lo enter
the
new
line.
The
old
tine
still
appears on
the screen, but your
computer
ignores
it.
When
you have two statements
with the
same
line
number, your
Commo-
dore
1B
only
uses
the
last
one entered. For example,
in
a
brief
pro-
gram
using the
COLOR command
to
change the colour
ol
the
screen
background, a mistake might occur:
10
COKOR
0,3 mistake
20
PRINT
"COMMODORE
16"
Press
the
etuiui key
to
gel
to
a
fresh
line,
and
just
retype
line
10
correctly
10
COLOR
0,3
Now
Ihe first line
1
is
replaced by
the
second
line
1
0.
You can check
48
I
I
this
by
typing
UST. which
displays a ilne-by-line
LISTing
of
your
program
as
it
is
stored
in the
computer's
memory.
When
you
LIST a
program,
all
lines
appear
In
correct order and the replaced lines don't
appear
The
screen
reads:
LIST RETURN
10
COLOR
0,3
20
PRINT
"COMMODORE
16"
You
can see what
the
COLOR
command
does
In this
example. For a
more
complete explanation, see
Chapter
6, or
look up
COLOR
in Ihe
BASIC
Encyclopedia.
Replacing
lines
In
a
program
is
also
a
good way
to
experiment with
your
computer
When
you
replace a
line,
the
new
one doesn't have
to
be
anything like Ihe old line.
For
example, instead ot correcting Ihe
spelling of
COLOR,
you can enter
this
line:
10
PRINT'COMMODORE
4
TIMES
COMMODORE
4
«^'
\
space
Now RUN
the
program anc see what happens.
5.
YOU CAN
ERASE
AN UNWANTED
LINE
just
by typing the
number
of
the line
and
pressing
HETuWi
The computer ignores the
line
even Ihough
it
still
appears
on
the
screen
Type
UST
to
get tne pro-
gram
LISTing to
make
sure the
line is
gone from
Ihe
program.
10
PRINT
"COMMODORE
4
TIMES
COMMODORE
4
-
"
20
PRINT
"COMMODORE
16"
Now
type
10
UST
RETURN
The
result,
according
to
your
computer
20
PRINT
"COMMODORE
16"
49