Apple IIe - Page 241

Apple
lie
Graphi
cs
241
The
offset
is
the
value
that
must
be
added
to
the
starting
address
of
the
table
to
obtain
the
starting address
of
a
specific
shape
definition
.
An
example
will
be
developed
using
the
previously
calculated
shape
definition
of
a square. The shape
table will
be
stored at
memory
locations
1
F00-1
FOD.
Therefore
,
memory
location
1FOO
must
contain
the
number
of
shape
definitions
in
the
table.
In
our
case
, this
is
one
.
1FOO
01
The
value
stored
in
the
next
location
is
insignificant.
1F01
00
The
memory
location
1
F02
and
1
F03
must
contain
the
value
of
the
offset
of
shape
definition
number
one.
The
starting
address
of
the
shape
definition
has
been
chosen at
1F04
.
The offset
from
1
FOO
is,
therefore
, 4 bytes.
1F04
-1FOO
0004
high
byte
=
00
low
byte
=
04
This
value
must
be
stored
in
memory
locations
1F02-1F03. Values
must
be
stored
low
byte
first. This means
that
the
04
is
stored
in
location
1
F02
.
1F02
04
low
byte
1F03
00
high
byte