.SPACING 2
.LEFT MARGIN 4
.RIGHT MARGIN 63
.FLAGS CAPITALIZE
\\
.FIGURE 15
.CENTER;<PASCAL FOR <RSX-11D AND <RSX-11M
.BLANK 2
.CENTER;BY
.BLANK 2
.CENTER;^JOHN ^R. ^BARR
.CENTER;^HUGHES ^AIRCRAFT ^COMPANY
.CENTER;^EL ^SEGUNDO, ^CALIFORNIA
.BLANK 5
.CENTER;^JUNE 1, 1977
.TITLE <PASCAL FOR <RSX-11D AND <RSX-11M
.PAGE
.P
^THE <PASCAL COMPILER AND RUN-TIME SYSTEM FOR <RSX-11D AND <RSX-11M
CONSISTS OF A BOOTSTRAP TWO-PASS COMPILER ADAPTED FROM THE <DOS
COMPILER ORIGINALLY DESIGNED BY ^BRIAN ^LUCAS FOR THE <PDP-11/45
SERIES OF COMPUTERS AT THE ^NATIONAL ^BUREAU OF ^STANDARDS.[2,3,4]##
^THE COMPILER AND RUN-TIME SYSTEM WERE MODIFIED AND CORRECTED IN
PLACES TO OPERATE UNDER THE <RSX-11 TASK ENVIRONMENT IN AN EFFORT
TO PRODUCE A <PASCAL COMPILER CAPABLE OF REPLACING <FORTRAN AND
AT TIMES <MACRO PROGRAMS.
<PASCAL PROVIDES A WELL STRUCTURED PROGRAMMING ENVIRONMENT WHICH
HAS BEEN LONG DESIRED AT ^HUGHES AND OTHER <RSX-11 INSTALLATIONS
IN THE ^SOUTHERN ^CALIFORNIA AREA.
^SINCE THIS EFFORT IS NOT YET COMPLETE, THIS PAPER WILL SERVE TO
PRESENT THE GOALS OF THE ^SOUTHERN ^CALIFORNIA <PASCAL EFFORT AND
ATTEMPT TO EXCITE OTHER INSTALLATIONS IN THE UTILITY OF <PASCAL
AND POSSIBLY OBTAIN SOME AID IN FUTURE WORK.
^AT THIS POINT IN THE DEVELOPMENT OF <PASCAL, ALL OF THE RECOGNITION
FOR WHAT <RSX-11 <PASCAL IS AT THIS TIME SHOULD GO TO ^BRIAN ^LUCAS,
AS HIS <DOS COMPILER SERVED AS THE BASIS FOR THE BOOTSTRAP COMPILER.
.P
^AS MANY PEOPLE PROBABLY KNOW, REWRITING A PROGRAM FOR <RSX-11 THAT
RUNS IN A <DOS ENVIRONMENT REQUIRES A CERTAIN AMOUNT OF PATIENCE AND
WILLINGNESS TO DIG INTO TWO SETS OF UNORGANIZED DOCUMENTATION IN 
WHICH THE ONE YOU ARE COMING FROM SEEMS SO MUCH BETTER THAN THE ONE
YOU ARE GOING TO YOU BEGIN TO WONDER WHY ME?
^IF IN ADDITION THE PROGRAM TO BE CONVERTED REQUIRES A LARGE
DEPENDENCY UPON THE CHARACTERISTICS OF THE ^LINKER AND REQUIRES
AN INTERFACE TO THE FILE SYSTEM OF <RSX-11 MORE HAIR PULLING ENSUES.
^HOWEVER, ^BRIAN ^LUCAS DID DEVELOPE A SET OF ^BLOCK ^STRUCTURED ^MACROS
FOR ASSEMBLY LANGUAGE BLOCK STRUCTURED PROGRAMMING WHICH AIDED IN THE
UNDERSTANDING OF THE TOTAL TASK.
^THE RUN-TIME ENVIRONMENT OF THE ^BLOCK ^STRUCTURED ^MACROS IS SIMILAR
TO THE <PASCAL ENVIRONMENT, AND MANY OF THE STRUCTURED CONSTRUCTS
USED IN <BSM REPRESENT HOW THE SEMANTICALLY EQUIVALENT CONSTRUCTS
IN <PASCAL ARE COMPILED.
<BSM SUPPORTS RECURSION, PROCEDURE CALLS WITH PARAMETERS, A HEAP,
A SIMPLE FILE SYSTEM, AND DYNAMIC ALLOCATION OF PROCEDURE VARIABLES
ON THE RUN-TIME STACK.
^THE <PASCAL COMPILER WHICH IS WRITTEN IN <BSM PROVIDES SIMILAR
CAPABILITIES AT A HIGHER LEVEL OF ABSTRACTION AND WITH A MUCH
MORE UNDERSTANDABLE PROGRAMMING INTERFACE.
.P
^WITH THE ABOVE HISTORY OF DEVELOPMENT, THE CURRENT <RSX <PASCAL
DOES NOT SATISFY OUR CURRENT DESIRES FOR A STABLE <PASCAL
PROGRAMMING SYSTEM. 
^HOWEVER, IT DOES PROVIDE A BOOTSTRAP COMPILER WITH WHICH WE CAN
WRITE A <PASCAL COMPILER WRITTEN IN <PASCAL THAT WILL INCLUDE
SOME OF THE INTERFACES TO <RSX-11 WHICH WE WOULD LIKE TO BE ABLE
TO USE FROM A LANGUAGE AS POWERFUL AND CAREFULLY DESIGNED AS
<PASCAL.
^THE CURRENT GOALS OF THE <PASCAL EFFORT ARE THEREFORE:
.LIST 1
.LE;^WRITE <PASCAL COMPILER IN <PASCAL.
.LE;^IMPROVE THE RUN-TIME SYSTEM BY INTEGRATING FILE SUPPORT INTO
THE DATA STRUCTURE OF THE COMPILED CODE AND INTERFACING THE <PASCAL
PROGRAMMER TO MORE OF THE <RSX-11 CAPABILITIES.
.LE;^DEFINE AND IMPLEMENT SOME OF THE ^CONCURRENT <PASCAL EXTENSIONS
DESIGNED BY ^PER ^BRINCH-^HANSEN WITHIN THE <RSX-11 OPERATING SYTEMS
SUCH THAT CONCURRENT PROCESSES CAN BE UTILIZED BY <PASCAL PROGRAMMERS
IN A RELIABLE MANNER.
.LE;^DOCUMENT, TEST, AND EVALUATE THE <PASCAL PROGRAMMING ENVIRONMENT
TO PRODUCE AN ACCEPTABLE AND COMPETITIVE TOOL.
.ELS
^THE REMAINDER OF THIS PAPER WILL BE A PRESENTATION OF HOW <PASCAL
PROGRAMS ARE STRUCTURED TO RUN IN THE <RSX-11 ENVIRONMENT WITH
EXAMPLES OF COMPILED CODE AND RUN-TIME ENVIRONMENTS.
.P
<PASCAL PROGRAMS FOR <RSX-11 CONFORM TO THE SYNTAX OF <PASCAL
PRESENTED BY ^JENSEN AND ^WIRTH.[1]##  ^THERE ARE CURRENTLY A
COUPLE OF EXCEPTIONS WHICH WILL BE REMOVED IN FUTURE RELEASES.
^PASCAL SOURCE FILES MAY BE GENERATED BY THE <RSX-11 EDITORS
(<EDIT, OR <TECO) EITHER AS ALL UPPER CASE TEXT OR AS A MORE
READABLE SOURCE WITH ALL RESERVED WORDS IN LOWER CASE.
^EXAMPLES OF SOURCE PROGRAMS WRITTEN IN UPPER CASE AND UPPER
AND LOWER CASE WHICH PRODUCE THE SAME RESULTS ARE CONTAINED
IN THE <PASCAL USER MANUAL FOR <RSX-11 INCLUDED AT THE END OF
THIS PAPER.
.P
^A <PASCAL PROCESS OR TASK CONSISTS OF THE FOLLOWING ELEMENTS:
.LIST 1
.LE;^PURE CODE FOR ALL PROCEDURES AND FUNCTIONS,
.LE;^PURE DATA DEFINED AS CONSTANTS OR CONSTANT PARAMETERS,
.LE;^A STACK CONTAINING THE RUN-TIME ENVIRONMENT,
.LE;^A HEAP CONTAINING DYNAMICALLY ALLOCATED PERMANENT VARIABLES,
.LE;AND THE RUN-TIME ROUTINES WHICH INTERFACE COMPILED <PASCAL
CODE TO THE <RSX-11 SYSTEM SERVICES.
.ELS
^FIGURE 1 IS THE TASK LAYOUT OF A <PASCAL PROGRAM WHICH HAS BEEN
TASK BUILT FOR <RSX-11.  ^THE <DOS VERSION OF <PASCAL ASSUMED THAT
THE STACK WOULD ALWAYS BE PLACED IMMEDIATELY BELOW THE <.BLANK.
PSECT AND THAT THE <.BLANK. PSECT COULD BE DECLARED AS A
GLOBAL, OVERLAYED PSECT ONLY CONTAINING DATA ITEMS GENERATED BY
THE <PASCAL COMPILER.
^WITHIN <RSX-11, THE <.BLANK. PSECT IS USED BY THE <FCS ROUTINES
AND MANY OTHER ROUTINES IN THE SYSTEM LIBRARY.
^THEREFORE, SINCE THE <.BLANK. PSECT COULD NOT BE USED FOR DATA,
AND SINCE IT IS IMPOSSIBLE TO PLACE ANOTHER PSECT BETWEEN THE
<.BLANK. PSECT AND THE STACK, DATA ITEMS ARE STORED IN THE
<PAS$$$ PSECT AND THE STACK IS TRANSFERED TO THE <PAS$$ PSECT
IMMEDIATELY UPON PROGRAM START.
^IF POSSIBLE, LATER RELEASES OF <PASCAL WILL REMOVE THIS KLUDGE
TO SATISFY THE UNMOVABLE <RSX-11 ENVIRONMENT.
^THE HEAP IS ALLOCATED IN THE ...... PSECT AND CONTAINS A ONE
WORD CONSTANT INDICATING THE SIZE OF THE HEAP.
^BOTH THE STACK (<PAS$$) AND THE HEAP (......) MAY BE EXTENDED
AT TASK BUILD TIME TO ALLOCATE THE PROPER AMOUNT OF RUN-TIME
SPACE.
^THE RUN-TIME ROUTINE CONTAINS ALL OF THE SUPPORT ROUTINES IN
ONE MODULE WITH STANDARD ACCESS TO THE <TI: TERMINAL (<LU=5)
AND UP TO THREE FILES (<LU-1,2,3).
^ADDITIONAL OR FEWER FILES MAY BE SUPPORTED BY REASSEMBLY
OF <PASLIB.MAC.
^AT PRESENT, THE FILE SUPPORT USES BOTH THE <FCS BUFFERS AND
BUFFERS WITHIN THE <PASCAL RUN-TIME ENVIRONMENT.
^FUTURE RELEASES SHOULD INTERFACE THE FILE SUPPORT DIRECTLY
TO THE RUN-TIME ENVIRONMENT OR THE RUN-TIME ENVIRONMENT
DIRECTLY TO THE <FCS BUFFERS.
.TEST PAGE 25
.BLANK 3
.NOFILL;.NOJUSTIFY
.SPACING 1
               _<.<BLANK.>
.BLANK 2
  ^^DDD\\NNN       ^PURE ^DATA
.BLANK 2
  ^^III\\MMM       ^PURE ^CODE
.BLANK 2
  ^^PAS$$\\        ^STACK
.BLANK 4
  ^^PAS$$$\\       ^STANDARD HEADER
               AND <I/O BLOCKS
.BLANK 2
               ^^FCS, PASLIB, \\AND ^^BUFFERS\\
.BLANK 2
  ......       <HEAP
.BLANK 3
.CENTER;^FIGURE 1. <PASCAL ^TASK ^IMAGE ^LAYOUT
.P
^THE FOLLOWING PROGRAM IS AN EXAMPLE OF THE RUN-TIME ENVIRONMENT
AVAILABLE IN <PASCAL.
^IT IS MERELY A PROGRAM TO TEST THE OPERATION OF A SPECIAL RECURSIVE
CONVERSION ROUTINE, BUT IT WILL EXEMPLIFY SEVERAL OPTIMAL CHARACTERISTICS
OF THE <PASCAL LANGUAGE AND COMPILER.
.TEST PAGE 30
.LIST 1
.NOFILL;.NOJUSTIFY
.BLANK 2
.SPACING 1
{$^T-} {DO NOT PRINT TABLES}
PROGRAM <TEST__OCTDEC;
CONST <CR=CHR(10); <NL=CHR(13); <FUBAR=100;
VAR <DEC : <INTEGER;
FUNCTION <OCTDEC ( <OCTVAL : <INTEGER ) : <INTEGER;
  VAR <DECIMAL    : <INTEGER;
      <REMAINDER  : <INTEGER;
      <NEWVAL     : <INTEGER;
  BEGIN
    <DECIMAL := <OCTVAL MOD 8;
    <REMAINDER := <OCTVAL DIV 8;
    IF <REMAINDER_#0 THEN
      BEGIN
        <NEWVAL := <OCTDEC( <REMAINDER );
        <DECIMAL := <DECIMAL + (10 * <NEWVAL)
      END;
    <OCTDEC := <DECIMAL;
  END;
  
BEGIN
  <DEC := <OCTDEC( <FUBAR );
^^  WRITE( OUT, NL, CR, FUBAR:6, DEC:6 );\\
^^  BREAK( OUT )\\
END.
.ELS
.FILL;.JUSTIFY
.SPACING 2
.BLANK 2
^THIS <PASCAL SOURCE GENERATES THE FOLLOWING LOAD MAP WHEN TASK BUILT:
.NOFILL;.NOJUSTIFY
.SPACING 1
.BLANK 3
^^
        : 000000 000307 000310 {UNUSED STACK}
_<. BLK.>: 000310 000401 000072 {LIBRARY ROUTINE}
_<III000>: 000402 000557 000156 {MAIN PROCEDURE CODE}
_<III001>: 000560 000703 000124 {OCTDEC FUNCTION CODE}
_<PAS$$ >: 000704 002703 002000 {EXTENDED STACK}
_<PAS$$$>: 002704 003117 000214 {TI: I/O BLOCKS}
--------: 003120 012455 007336 {NON-ESSENTIAL PSECTS}
_<......>: 012456 012555 000100 {EXTENED HEAP}
\\
.SPACING 2
.FILL;.JUSTIFY
.BLANK 2
^THE <PAS$$ AND <PAS$$$ PSECTS MUST BE IN ORDER, AND THE <TI: <I/O
BLOCKS AND GLOBAL CONSTANTS WILL BE REFERENCED BY NEGATIVE DISPLACEMENTS
FROM THE TOP OF THE STACK.
^THE FOLLOWING ANNOTATED OBJECT CODE WAS GENERATED BY THE <PASCAL
COMPILER, AND REPRESENTS A DUMP OF THE TASK IMAGE.
.BLANK 3
.SPACING 1
.NOFILL;.NOJUSTIFY
PROGRAM <TEST__OCTDEC;
CONST ^^CR=CHR(10); NL=CHR(13); FUBAR=100;\\
VAR <DEC:INTEGER;
BEGIN
^^
  
012706  MOV _#2704,SP      ;SET NEW STACK POINTER
002704
010605  MOV SP,R5         ;SET ENVIRONMENT POINTER
012700  MOV _#12456,R0     ;POINTER TO HEAP
012456
004767  JMP PC,$$$000     ;INITIALIZE ENVIRONMENT AND HEAP
002500
005046  CLR -(SP)         ;MAKE ROOM FOR
005046  CLR -(SP)         ;TEMPORARY VARIABLES
  
  DEC := OCTDEC(FUBAR);
  
012746  MOV _#144,-(SP)    ;OCTDEC FORMAL PARAMETER
000144
010504  MOV R5,R4         ;SAVE ENVIRONMENT POINTER
004767  JSR PC,OCTDEC     ;CALL CONVERSION FUNCTION
000122
012665  MOV (SP)+,-2(R5)  ;RETURNED VALUE
177776
  
  WRITE(OUT,NL,CR,FUBAR:6,DEC:6);
  
012746  MOV _#2716,-(SP)   ;OUT FILE BLOCK POINTER
002716
011665  MOV (SP),R5       ;SET CURRENT FILE BLOCK POINTER
000010
012746  MOV _#15,-(SP)     ;NL CHARACTER
000015
005046  CLR -(SP)
004767  JMP PC,$$$025     ;WRITE CHARACTER
004604
016546  MOV 10(R5),-(SP)  ;OUT FILE BLOCK ADDRESS
000010
012746  MOV _#12,-(SP)     ;CR CHARACTER
000012
005046  CLR -(SP)
004767  JSR PC,$$$025     ;WRITE CHARACTER
004566
016546  MOV 10(R5),-(SP)  ;OUT FILE BLOCK ADDRESS
000010
012746  MOV _#144,-(SP)    ;CONSTANT 100 (FUBAR)
000144
012746  MOV _#6,-(SP)      ;INTEGER FIELD LENGTH
000006
004767  JSR PC,$$$031     ;WRITE INTEGER
005140
016546  MOV 10(R5),-(SP)  ;OUT FILE BLOCK ADDRESS
000010
016546  MOV -2(R5),-(SP)  ;VARIABLE (DEC)
177776
012746  MOV _#6,-(SP)      ;INTEGER FIELD LENGTH
000006
004767  JSR PC,$$$031     ;WRITE INTEGER
005120
  
  BREAK(OUT)
  
012746  MOV _#2716,-(SP)   ;OUT FILE BLOCK ADDRESS
002716
004767  JSR PC,$$$023     ;BREAK
004266
  
\\END.^^
  
010506  MOV R5,SP         ;STACK TO STARTING LOCATION
000167  JMP $$$001        ;EXIT
.BLANK 2
\\AND THE <OCTDEC FUNCTION CODE IS:^^
.BLANK 2
\\FUNCTION^^ OCTDEC(OCTVAL:INTEGER):INTEGER;
  
010546  MOV R5,-(SP)      ;SAVE PREVIOUS ENVIRONMENT
010446  MOV R4,-(SP)      ;AND STATIC LINK IF SET
010605  MOV SP,R5         ;NEW BASE FOR THIS INSTANCE
  
\\  VAR ^^DECIMAL:INTEGER;
      REMAINDER:INTEGER;
      NEWVAL:INTEGER;
  
162706  SUB _#6,SP         ;ALLOW ROOM FOR VARIABLES
000006
  
\\  BEGIN^^
    DECIMAL := OCTVAL\\ MOD^^ 8;
  
016500  MOV 6(R5),R0      ;PASSED PARAMETER
000006
042700  BIC _#177770,R0    ;MOD FUNCTION BASE 8
177770
010065  MOV R0,-2(R5)     ;SET DECIMAL
177776
  
    REMAINDER := OCTVAL\\ DIV^^ 8;
  
016500  MOV 6(R5),R0      ;PASSED PARAMETER
000006
072027  ASH R2,_#-3        ;DIV BY BASE 8
177775
010065  MOV R0,-4(R5)     ;SET REMAINDER
177774
  
    \\IF^^ REMAINDER_#0\\ THEN^^
  
005765  TST -4(R5)        ;TEST THE RESULT
177774
001415  BEQ               ;IF ZERO SKIP THEN CLAUSE
  
\\    BEGIN^^
        NEWVAL := OCTDEC(REMAINDER);
  
005046  CLR -(SP)
016546  MOV -4(R5),-(SP)  ;ACTUAL PARAMETER
177774
004767  JSR PC,OCTDEC     ;CALL THE FUNCTION RECURSIVELY
177716
012665  MOV (SP)+,-6(R5)  ;RETURNED RESULT TO NEWVAL
177772
  
      DECIMAL := DECIMAL + (10 * NEWVAL);
  
012701  MOV _#12,R1        ;CONSTANT 10.
000012
070165  MUL R1,-6(R5)     ;MULTIPLY NEWVAL BY 10.
177772
060165  ADD R1,-2(R5)     ;ADD DECIMAL
177776
  
\\    END;^^
    OCTDEC := DECIMAL;
  
016565  MOV -2(R5),10(R5) ;RETURN RESULT TO PROCEDURE
177776
000010
  
\\  END;^^
  
010506  MOV R5,SP         ;RESTORE STACK POINTER
005726  TST (SP)+         ;REMOVE STATIC LINK
012605  MOV (SP)+,R5      ;RESTORE PREVIOUS ENVIRONMENT
012604  MOV (SP)+,R4      ;RETURN ADDRESS
005726  TST (SP)+         ;REMOVE ACTUAL PARAMETER
000114  JMP (R4)          ;RETURN TO CALLER
.SPACING 2
.BLANK 2
.FILL;.JUSTIFY
\\
^THE CONFIGURATION OF THE STACK AFTER TWO CALLS TO <OCTDEC IS
SHOWN IN ^FIGURE 2.
.TEST PAGE 20
.BLANK 3
.LIST 1
.NOFILL;.NOJUSTIFY
.SPACING 1
^^
001740:    000012  SP  <NEWVAL
001742:    000001      <REMAINDER
001744:    000004      <DECIMAL
001746:  --------  R5
001750:    001766
001752:  _<RETURN>
001754:    000014      <PARAMETER
001756:    000000      <RETURN <VALUE
001760:  --------  SP  <NEWVAL
001762:    000014      <REMAINDER
001764:    000004      <DECIMAL
001766:  --------  R5
001770:    <PAS$$$
001772:  _<RETURN>
001774:    000144      <PARAMETER
001776:    000000      <RETURN <VALUE
002000:    000000
<PAS$$$:
.ELS
.SPACING 2
.FILL;.JUSTIFY
\\
.BLANK 2
.CENTER;^FIGURE 2. <PASCAL ^STACK ^FRAME
.BLANK 2
^THE STACK FRAME IN ^FIGURE 2 REPRESENTS THE RESULTS OF CALLING
<OCTDEC ONCE FROM THE MAIN PROCEDURE, TWO TIMES WITHIN <OCTDEC
AND AFTER THE RETURN OF THE LAST CALL TO <OCTDEC.
^THE TEMPORARY VARIABLES (<DECIMAL, <REMAINDER, AND <NEWVAL) ARE
COPIED ONTO THE STACK FOR EACH CALL TO <OCTDEC.
^THE <SP AND <R5 POINTERS ARE SHOWN FOR EACH INSTANCE OF <OCTDEC.
.P
^IN SUMMARY, THE CURRENT IMPLEMENTATION OF <PASCAL FOR <RSX-11
IS A USEFUL TOOL AS IT STANDS, BUT MUCH MORE WORK IS TO BE DONE
TO MAKE IT A STABLE PRODUCT WHICH CAN BE USED BY ALL PROGRAMMERS.
^AT THE PRESENT TIME, THE <PASCAL COMPILER DOES NOT USE THE
GET COMMAND LINE FACILITY OF <RSX-11 AND DOES NOT PASS THE
INTERMEDIATE FILE TO THE SECOND PASS OF THE COMPILER IN A
SATISFACTORY MULTI-USER ENVIRONMENT.  ^AS LONG AS ONLY ONE
PERSON PER <UIC IS USING THE COMPILER THE USE OF A FIXED
FILE NAME FOR THE INTERMEDIATE FILE IS SUFFICIENT, BUT
IT IS POSSIBLE TO GET INTO PROBLEMS.
^IN ADDITION, THE COMPILER WILL SOMETIMES FAIL TO PARSE
CERTAIN ERRONEOUS STATEMENTS IN SUCH A MANNER THAT IT GETS
INTO A LOOP WITHOUT INFORMING THE USER OF WHERE THE ERROR
HAS OCCURRED.
.P
^ANY ASSISTANCE IN MAKING <PASCAL A SOLID PROGRAMMING TOOL
WILL BE ACCEPTED.  ^WE WOULD LIKE TO HAVE SEVERAL INSTALLATIONS
WORKING ON <PASCAL WITH DIVERSE INPUTS REGARDING WHAT FUTURE
RELEASES SHOULD INCLUDE.
.BLANK 5
<REFERENCES:
.LIST 1
.LE;^JENSEN, ^KATHLEEN AND ^NIKLAUS ^WIRTH, "<PASCAL: ^USER ^MANUAL
AND ^REPORT," ^SPRINGER-^VERLAG, ^NEW ^YORK, 1975.
.LE;^LUCAS, ^BRIAN, "^BLOCK ^STRUCTURED ^MACROS,"
^NATIONAL ^BUREAU OF ^STANDARDS, ^TECHNICAL ^NOTE, <SSGN 73-2, ^JUNE 14, 1973.
.LE;^LUCAS, ^BRIAN, "^AN ^IMPLEMENTATION OF ^RECURSION AND ^BLOCK
^STRUCTURE ON THE <PDP-11," ^NATIONAL ^BUREAU OF ^STANDARDS,
^TECHNICAL ^NOTE, <SSGN 73-5, ^JULY, 1973.
.LE;^LUCAS, ^BRIAN, "^USER'S ^GUIDE FOR ^BLOCK ^STRUCTURED ^MACROS,"
^REVISION 1, ^NATIONAL ^BUREAU OF ^STANDARDS, ^TECHNICAL ^NOTE,
<SSGN 74-1, ^JULY 1974.
.ELS