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END
The local symbol definitions of X, Y, and Z in the main
program are suspended when PR2 i:s called (1). The
procedure-local symbol definitions in PR2 are suspended
when PRl is called (2). When the PEND statement of
PR
1
is encountered, the local definitions in PR2 are re-
activated (3). When the PE ND of PR2 is encountered,
the local definitions in the main program are reactiva-
ted
(4).
Thus, the three occurren,ces of LOCAL
X,
Y,
and Z do not confl ict.
PAGE
Begin A New Page
The PAGE directive causes the assembly listing to be ad-
vanced to a new page; its form is
L_
L::..;a:;c,;b;...::e...:...I_-+-_-,C:...:ommand
L, ___
L - - _
P _
AGE
E:,gument
A label field entry is ignored by
thE~
assembler unless it is
the target label of a GOTO search. Argument field en-
tries are a Iways ignored.
If the line of code following the PAGE directive would
normally appear at the top of a page, the directive is
ignored.
The PAGE directive is effective only at assembly time.
No
code is generated for the object program as a result of its
use.
PCC
Print Control Cards
The PCC directive controls the priMing of LIST, PAGE,
TITLE, and SPACE statements; its form is
L_
L_a_b_e_I_-+-_-::cC--=ommand
Argument
L
pcc
---+--n~~---------~
where
n
is an evaluatable abso
IUh:J
expression (no lit-
eral, e~ternal, or forward references) indicat-
ing whether or not to print succeeding control
cards in the assembly listing.
If the value of n
is zero, printing of LIST, PAGE, TITLE, and
SPACE statements wi
II
be suppressed unti
I
the
next PCC statement is encountered.
Otherwise
(e.g., before any
pce
stotement), all LIST,
PAGE, TITLE, and SPACE: statements wi II be
printed in the assembly ,"sting as they occur,
before being executed by the Extended Symbol
processor.
REF
Declare Externa I References
The REF directive declares which symbols referenced in this
assemb Iy are defined in some other (separately assembled)
program. The directive has the form
Command
Ar ument
REF
symbol
1 [,
symbol
2
, •.. , symbol
n
]
where each symbol may be any label that is to be satisfied
at load time by other programs.
A label field entry is ignored by the assembler.
The REF directive causes the loader to load programs whose
labels it references. At load time all symbols that have ap-
peared in the argument field of REF statements and were
referenced in the source program must be satisfied by cor-
responding external definitions (DEF's) in another program.
It
is not necessary that a program containing a REF direc-
tive reference all symbols declared by REF.
Unrefer-
enced REFs will not be flagged as errors on the assembly
listing.
Example 26.
REF Directive
REF
IOCNTRL, TAPE, TYPE, PUNCH
This statement identifies the labels JOCNTRL, TAPE,
TYPE, and PUNCH as symbols for which external
definitions will be required at load time.
S:STEP
Step Source Input
The S:STEP directive causes a temporary suspension of input
from the SI device. It is primari Iy of use for source input
from paper tape
I
where large programs must be main-
tained on separate reels. This directive has the form
Label
Command
Argument
S: STEP
When the S:STEP directive is encountered during the en-
coder pass (during SI input), the assembler wi
Ir
output the
message
I
STEP HIT
~------~
on the OC device. Then the Monitor's M:WAIT routine is
called to allow the operator to mount the next paper tape
reel. When the operator continues the job, assembly is
resumed with the next record from the SI device.
Extended Symbol Directives
37
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