Apple IIe - Page 274

274
Apple
lie
Users
Handbook
Activating the 80-Column
Board in BASIC
To
enable
the
80-column
board
, first
power-up
the
computer
as
usual.
Then,
after
Applesoft
has
control
of
the
computer
,
enter
the
following,
PR#3
to
activate
the
board
.
It
is
usually
convenient
to
depress
the
CAPS
LOCK
key
since
Applesoft
does
not
understand
lowercase
letters.
The
statement
PR#3
may seem a
bit
obscure. The
PR#3
command
is
executed
because
the
auxiliary
expansion
slot
is
hard-wired
to
peripheral
slot
number
three
.
Recall
that
PR#
is
the
BASIC
statement used
to
activate a
peripheral
for
output.
Since
non-Apple
manufactured
80-column
boards
are
tradition-
ally used
in
peripheral
slot
#3,
the
auxiliary
expansion
slot
has
been
hard-wired
to
this
slot
.
This
wiring
arrangement
has
one
drawback.
If
any
peripheral
card
is
inserted
in
slot
#3
,
it
will
be
rendered
inactive
by
the
80-column
board
.
The
effect
of
activating
the
80-column
board
is
that
the
screen
is
cleared.
Next,
the
80-column
cursor
will
be
displiiyed
.
The
80-
column
cu
rsor is
only
half
as
wide
as
the
standard
BASIC
cursor
.
It
is
solid
instead
of
checkered,
and does
not
blink
.
Everytime
the
computer
is
powered
-
up
,
the
80-column
c
ard
must
be
activated
before
it
is
used. This may
prove
to
be
quite
tedious.
This
tedium
is
inevitable
in
a cassette based system.
However
, this
situation
can
be
remedied
in
a
disk
based system.
The
80-col
umn
board
can
be
activated each ti
me
a specific
disk
is
used
through
modification
of
the
HELLO
program
on
that
disk
.
The
DOS HELLO
program
is
a
BASIC
program
that
is
executed
during
the
power-up
procedure
. The
computer
runs
this
pro-
gram
automatically
.
The
HELLO
program
contains
information