Radio Shack TRS-80 Owner's Manual page 112

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TRS-80
MODEL
III
DISK SYSTEf
&»dddd
dddd
is
a
1
to 4 digit
sequence composed
of
hexadecimal numerals
0.1....9.A.B
F.
zaddddd
ddddd
is
a
sequence
of octal
numerals 0,1...
7
and
&oddddd =177777
decimal.
Note: The
o
can be omitted from
the prefix &o. Therefore
&oddddd=
&ddddd.
The
constants always represent signed
integers. Therefore any
hex number
greater than &H7FFF, or
any
octal
number
greater than &077777,
will
be
interpreted as a
negative
quantity.
The
following
table
illustrates
this:
Octal
Hex
Decimal
&1 &H1
1
&2
&H2
2
&77777 &H7FFF
32767
& 100000 &H8000
-32768
&1 00001
&H8001
-32767
&
100002
&H8002
-32766
& 177776 &HFFFE
-2
&
177777
&HFFFF -1
Hex
and
octal constants
cannot be typed
in as responses
to
an input prompt
or
be contained
in
a
data
statement.
Often
the
hex
or
octal
constant must
be
enclosed
in
parentheses
to
prevent a syntax
error
from
occurring.
Examples
PRINT &H5200, &O51000
prints the
decimal
equivalent of
the
two
constants (both equal
20992).
POKE &H3C00* 42
puts
decimal 42
(ascii
code
for
an
asterisk) into
video
memory
address hex
3C00.
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