These
'user
defined characters'
can
be made up using
any
combination of 0 to 64 dots,
arranged
in
any
order -
so
the
'complete' character
set
that
uses all possible
combinations of
this
matrix
would comprise
many
more different characters. Add to
this
the
fact
that
you
can
group blocks of characters together to form
larger
block
characters,
and
the
possibilities for user-defined graphics
are
limited only by your
time
and
ingenuity.
Logic ....
A major difference between a calculator
and
computer is
the
computer's ability to
handle
logical operations
in
applications like
the
conditional
1FT
HEN
sequence.
To
do
this,
the
logical operators
treat
the
values to which they
are
applied as
bit
patterns
(bit-wise),
and
operate on
the
individual bits. The description
and
use is
entirely, well ....
er
logical -
but
it
is notoriously difficult to describe logic
in
simple
terms
without
the
precision of concise definitions.
The two halves of
the
logical expression
are
known as
the
arguments. A logical
expression comprises:
< argument> [ <logical operator> <argument> ]
where:
<argument>
is:
NOT
<argument>
or: <numeric expression>
or: <relational expression>
or: «logical
expression»
Both
the
arguments
for a logical operator
are
forced to integer representation,
and
ERR
or 6
results
if
an
argument
will
not
fit into
the
integer range.
The logical operators,
in
order of precedence,
and
their
effect on each
bit
are:
AND
Result
is 0 unless
both
argument
bits
are
1
o R Result is 1 unless
both
argument
bits
are
0
X 0 R
Result
is 1 unless
both
argument
bits
are
the
same
AND
is
the
most commonly employed logical operator,
and
does NOT
mean
'add'.
PRINT
10
AND
10
Results
in
1 0
PRINT
10
AND
12
Results
in
8.
Chapter 9 Page
18
At
your leisure
....
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