ADDRESS (EXPRESSION) CONSTANT
An address may be stored as a two-byte constant.
There must be a separate statement line for each
constant of this type. The constant is enclosed in
parenthesis and preceded by an A as in the follow-
ing example s.
stores the current value of the Location Counter
- 6 as a constant (RELOCATABLE).
Stores the value of STRT as a constant (RE-
Stores the binary equivalent of 256 as a con-
stant (NOT RELOCATABLE).
DEFINING REPETITIVE CONSTANTS
Constants in character and hexadecimal form may be
defined in repetitive fashion.
In the format above, g represents the actual number
of constants to be generated, and 'cv' represents
the constant value.
generate ABCABCABC and 03F403F4.
The g factor may not be properly incorporated in an
address constant statement.
The implied length of CONI and CON2, in the above
example, is three and two.
DEFINING EXPLICIT CONSTANT LENGTHS
The define constant format may be expanded to in-
clude specific references to length.
L may not exceed 256 10
number of bytes
n may not exceed (16)10
The explicit length takes precedence if it does not
correspond to the physical length of the 'cv' value.
In the third example above, the B, rightmost char-
acter of the constant lAB, was truncated because a
length of two was specified. In like manner, the
constant defined on the second line was padded-out
to a length of fi ve .
If an explicit length is not included when defining an
ExpressionConstant, a lengthof 4 bytes is assumed,
and the generated constant is aligned on an even word
When a length other than four (4) is specified, the
constant is not aligned and is not relocatable. If the
value of the expression exceeds the assigned num-
ber of bytes, the high-order bits of the value are
Absolute expressions may have negative values which
are generated in 2's complement form.
PROGRAM LINKING CODES
The two codes, ENTRY and EXTRN, provide com-
munication between two programs that have been
assembled independently. The ENTRY code speci-
fies the location(s) addressed by another program.
The EXTRN code defines a symbol in another pro-
A separate ENTRY verb must appear for each entry
point in the program (see START code for exception).
ENTRY appears in the OPERATION field and a sym-
bol must be used in the OPERAND field. The NAME
field is not used on this line.