SPOS UNIT 2 MACRO NOTES SPOS UNIT 2 MACRO NOTESSPOS UNIT 2 MACRO NOTESSPOS UNIT 2 MACRO NOTES

Course Objectives:
▪To get acquainted with the basics of System Programming.
▪To acquire knowledge of data structures used in the design of System
Software.
▪To be familiar with the format of object modules, the functions of linking,
relocation, and loading.
▪To comprehend the structures and functions of Operating Systems and
process management.
▪To deal with concurrency and deadlock in the Operating System.
▪To learn and understand memory management of Operating System.
310243: Systems Programming and Operating
System
1
8/2/2024

Course Outcomes:
On completion of the course, learners should be able to-
CO1: Analyze and synthesize basic System Software and its functionality.
CO2: Identify suitable data structures and Design & Implement various System
Software
CO3: Compare different loading schemes and analyze the performance of linker
and loader
CO4: Implement and Analyze the performance of process scheduling algorithms
CO5: Identify the mechanism to deal with deadlock and concurrency issues
CO6: Demonstrate memory organization and memory management policies
310243: Systems Programming and Operating
System
2
8/2/2024

Macro Processor and Compiler
3
8/2/2024
UNIT-II

Syllabus
Introduction, Features of a Macro facility: Macro instruction
arguments, Conditional Macro expansion, Macro calls within Macros,
Macro instructions defining Macro, Design of two pass Macro
processor, Concept of single pass Macro processor
Introduction to Compilers: Phases of Compiler with one example,
Comparison of Compiler and Interpreter
#Exemplar/Case Studies: GNU M4 Macro Processor
Mapping of Course Outcomes for Unit II: CO1, CO2, CO3
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8/2/2024

Introduction to Macro
Processor
◦ Macro instructions are considered as the extension of the
basic assembler language.
◦ A macro instruction is convenient for the programmer in
terms of notation.
◦ A macro is a single-line abbreviation used for a group of
instructions.
◦ It allows the programmer to write shorthand version of a
program (module programming)
◦ The macro processor replaces each macro call with the
corresponding sequence of statements (expanding)
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Macro Processor
Working of Macro Processor
1. Recognizes macro definitions
2. Saves the macro definition
3. Recognizes macro calls
4. Expands macro calls
Source
Code
(with macro)
Macro
Processor
Expanded
Code
Compiler or
Assembler
obj
6
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Macro Definition
MACRO Start of Definition
<Macro Name> <List of Parameters [p1, p2, …pn]>
Macro Name (with label or argument(s)
which is optional)
-------------
------------- Sequence to be abbreviated
-------------
MEND End of Definition
7
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Macro Definition
MACRO (Start of Definition):-This keyword indicates the beginning of a
macro definition. It signals to the macro processor that what follows is
a macro to be defined.
<Macro Name> <List of Parameters [p1, p2, …pn]>:-This is the
identifier you use to call the macro. These are optional and define the
placeholders that can be used within the macro body
Sequence to be abbreviated:-This section contains the actual code or
instructions that the macro will expand into. It represents the body of
the macro and includes any logic or operations defined by the macro.
MEND (End of Definition):-This keyword signifies the end of the
macro definition. It tells the macro processor that the macro
definition is complete, and any subsequent code will not be part of
this macro.
8

Macro Definition (cont..)
Example:
MACRO
ADDS &arg1, &arg2, &arg3
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND
8/2/2024 9

Macro Call
<Macro Name> <List of Actual parameters[ a1, a2, …an]>
For Ex.🡪
ADDS DATA1, DATA2, DATA3
A macro call is a statement in the source code that invokes a
previously defined macro, replacing it with the macro’s body or
definition.
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Macro Expansion
//Source Code with Macro definition &
macro call
MACRO
ADDS &arg1,&arg2,&arg3
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND
PROG START 0
BALR 15,0
USING *,15
SR 4,4
DATA1 DC F’3’
DATA2 DC F’4’
DATA3 DS 1F
END
// Processed code after macro
Expansion
PROG START 0
BALR 15,0
USING *,15
L 1, DATA1
A 1, DATA2
ST 1,DATA3
SR 4,4
DATA1 DC F’3’
DATA2 DC F’4’
DATA3 DS 1F
END
Macro
Expansion
8/2/2024 11

Macro Expansion (cont..)
Source program with Macro Definition & Macro call
MACRO
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND
PROG START 0
BALR 15,0
USING *,15
SR 4,4
ADDS D4, D5, D6
DATA1 DC F’3’
DATA2 DC F’4’
DATA3 DS 1F
D4 DC F’1’
D5 DC F’2’
D6 DS 1F
END
Source program after macro expansion
PROG START 0
BALR 15,0
USING *,15
L 1, DATA1
A 1, DATA2
ST 1, DATA3
SR 4, 4
L 1, D4
A 1, D5
ST 1, D6
DATA1 DC F’3’
DATA2 DC F’4’
DATA3 DS 1F
D4 DC F’1’
D5 DC F’2’
D6 DS 1F
END
1st
Macro
call
2nd
Macro
call
12
MACRO
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND

• Macro expansion in programming generally refers to the process
of replacing macros with their defined code.
• Definition Replacement: A macro is a shorthand for a code
snippet or a set of instructions. During macro expansion, the
preprocessor replaces macro names with their corresponding
code as defined in the macro's definition.
• Tasks involved in macro expansion :-
• 1. Identify the macro calls in the program.
• 2. The values of formal parameters are identified.
• 3. Maintain the values of expansion time variables declared in a
macro.
• 4. Expansion time control flow is organized.
• 5 . Determining the values of sequencing symbols
• 6 . Expansion of a model statement is performed
13

Parameter Substitution
▪Positional Formal Argument
▪Keyword Argument
▪Default Argument
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Positional Formal Argument
// MACRO DEFINITION
MACRO
ADDS &arg1, &arg2, &arg3
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND
/MACRO CALL
Formal Parameter Actual Parameter
&arg1 DATA1
&arg2 DATA2
&arg3 DATA3
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Keyword Argument
//MACRO DEFINITION
MACRO
ADDS &arg1=, &arg2=, &arg3=
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND
//MACRO CALL
ADDS &arg1=DATA1, &arg2= DATA2, &arg3= DATA3
……
ADDS &arg2= DATA2, &arg3= DATA3, &arg1=DATA1
Formal Parameter Actual Parameter
&arg1 DATA1
&arg2 DATA2
&Arg3 DATA3
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Default Argument
//MACRO DEFINITION
MACRO
ADDS &arg1=, &arg2=, &arg3=4
L 1, &arg1
A 1, &arg2
ST 1, &arg3
MEND
/MACRO CALL
ADDS &arg1=D1, &arg2= D2
……
ADDS &arg2= D2, &arg1=D1
ADDS &arg2= D2, &arg1=D1, &arg3=100
Formal Parameter Value
&arg1 D1
&arg2 D2
&arg3 100
//it overrides default value
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Macro with Mixed Parameter Lists
Macro can use all three types of parameters together
Example:-
//MACRO DEFINITION
MACRO
ADDS &arg1, &arg2=45, &arg3=
L 1, &arg1
A 1, &arg2
ST 1,&arg3
MEND
//MACRO CALL
ADDS D1, &arg3= D3
……
ADDS D1, &arg3=D6, &arg2=400
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19
Macro Function
Macro is preprocessed. Function is compiled.
Macro does not support type
checking.
Function support type
checking.
Program length increases. Program length remain same.
There is side effect while
using macro.
No side effect while using
function.
Execution is faster. Execution is slower.
Useful where small source
code appears many time.
Useful where large source
code appears many time.
Macro does not check
compile errors.
Function checks compile
errors.

Macro vs. Subroutine
Macro:
▪ Every macro call is
replaced by its definition.
▪ After expansion of
program, length increases.
So, more memory is
required.
▪ Processing time is less as
compared to subroutine
processing, because there
is no context switching
during macro processing.
Subroutine
▪ Every Subroutine (function)
call transfers control to the
first instruction of subroutine
which is called.
▪ After processing subroutine
call, the program size
remains same.
▪ Processing time is increased
due to context switching.
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Advanced Macro Facilities
▪Macro Calls within Macros
(Nested Macro Calls)
▪Macro instruction defining Macros
▪Conditional Macro Expansion
▪Expansion time variables
▪Expansion time Loops
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Macro Calls within Macros
(Nested Macro Calls)
Macro definition of one macro may generate call to another macro is called as nested
macro calls.
Example.
MACRO
ADD1 &arg
L 1, &arg
A 1, =F’1’
ST 1, &arg
MEND
MACRO
ADDS &arg1, &arg2 ,&arg3
ADD1 &arg1
ADD1 &arg2
MEND
Call to macro
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Macro Calls within Macros
(Nested Macro Calls) (cont..)
//Source Code
:
:
MACRO
ADD1 &arg
L 1, &arg
A 1,=F’1’
ST 1,&arg
MEND
MACRO
ADDS &a1,&a2,&a3
ADD1 &a1
ADD1 &a2
CMP 1,&a3
MEND
:
:
ADDS A, B, C
:
:
A DC F’3’
B DC F’13’
C DC F’6’
:
:
// Level-1 Expansion of
Source Code
:
:
:
:
:
:
:
:
:
:
:
:
ADD1 A
ADD1 B
CMP 1, C
:
:
:
:
Expansion
Of ADDS
// Level-2 Expansion of
Source Code
:
:
:
:
:
:
:
:
:
L 1, A
A 1, =F’1’
ST 1, A
L 1, B
A 1, =F’1’
ST 1, B
CMP 1, C
:
:
:
:
Expansion
of ADD1
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Macro Instruction Defining Macros
Macro definition may defines another macro
Ex.
MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,V(&SUB)
BALR14,15
MEND
MEND
Macro calls
◦ DEFINE COS
◦ COS AR
Inner
Macro
Outer
Macro
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Conditional Macro Expansion
AIF & AGO are used for conditional macro expansion
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• Conditional macro expansion involves using conditional directives
within a macro to control which instructions are included in the
expansion.
• These directives allow the macro to expand differently depending on
the values of parameters or other conditions.
Implementation of conditional macro expansion:-
1. IF-ELSE-ENDIF structure :-When an IF statement is encountered
during the expansion of a macro, the specified Boolean expression
is evaluated.
a. For TRUE : The macro processor continues to process lines from
DEFTAB until it encounters the next ELSE or ENDIF statement. If
ELSE is encountered, then skips to ENDIF.
27

b. For FALSE : The macro processor skips ahead in DEFTAB until it
finds the next ELSE or ENDIF statement.
2. WHILE-ENDW structure :-
When WHILE statement is encountered during the expansion of a
macro, the specified Boolean expression is evaluated.
For TRUE : The macro processor continues to process lines from
DEFTAB unit it encounters the next ENDW stetement. When ENDW
is encountered, the macro processor returns to the proceding
WHILE, re - evaluates the Boolean expression and takes action based
on the new value.
For FALSE : The macro processor skips ahead in DERTAB until it finds
the next ENDW statement and then resumes normal macro
expansion.
28

For ex.
MYMACRO MACRO CONDITION
IF CONDITION
MOV AX, 1
ELSE
MOV AX, 0
ENDIF
ENDM
Here,
• If ‘CONDITION’ is true when ‘MYMACRO’ is called, the macro will expand to include ‘MOV AX,1’
• If ‘CONDIYION’ is false the macro will expand to include ‘MOV AX, 0’.
29

Need of Conditional Macro Expansion
Lets consider example:
:
:
LOOP1 A 1, A1
A 2, A2
A 3, A3
:
:
LOOP2 A 1, A3
A 2, A2
:
:
LOOP3 A 1, A1
:
:
A1 DC F’5’
A2 DC F’15’
A3 DC F’10’
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MACRO
&a0 VARY &CNT, &a1, &a2, &a3
&a0 A 1, &a1
AIF (&CNT EQ 1) .FINI
A 2,& a2
AIF (&CNT EQ 2) .FINI
A 3, &a3
.FINI MEND
:
:
LOOP1 VARY 3, A1, A2, A3
:
:
LOOP2 VARY 2, A3, A2
:
:
LOOP3 VARY 1, A1
:
:
A1 DC F’5’
A2 DC F’15’
// Expanded Source code
:
LOOP1 A 1, A1
A 2, A2
A 3, A3
:
:
LOOP2 A 1, A3
A 2, A2
:
:
LOOP3 A 1, A1
:
:
A1 DC F’5’
A2 DC F’15’
A3 DC F’10’
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AIF , .FINI, AGO
.FINI :- it is macro label and don’t appear in output of macro processor.
AIF(&count EQ 1).FINI:- The pseuodo op directs the macro processor to
skip the statement labeled .FINI, if “&count” value is 1; otherwise , the
macro processor is to continue with the statement following AIF
pseuodo op.
AGO:- it is unconditional branch pseudo op like “go to”.
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MACRO WITHIN MACROS
Macro Within a Macro
• When a macro is defined within another macro, it means that the inner
macro can be invoked as part of the expansion of the outer macro.
• The outer macro will include the invocation of the inner macro, and
during expansion, the inner macro will also be expanded.
Why Use Macro Within a Macro?
• Modularity: Each operation is defined separately, making the code easier
to read and maintain.
• Reusability: The inner macro can be reused in different parts of the outer
macro or even in other macros.
• Clarity: It helps in organizing the code better by separating different
logical operations into distinct macros.
33

FOR EX.
INCREMENT MACRO REG
INC REG
ENDM
DOUBLE_INCREMENT MACRO REG
INCREMENT REG
INCREMENT REG
ENDM
Here,
In this ex. ‘INCREMENT’ is simple macro that increment value of register.
‘DOUBLE_INCREMENT’ is another macro that uses the ‘INCREMENT’ macro twice to
increment the register twice.
When ‘DOUBLE_INCREMENT’ is invoked, it expands to two calls of ‘INCREMENT’
macro.
34

In a single-pass macro processor, the macro processing is
done in a single pass over the source code. This means that
the processor reads the entire source code only once to
perform macro expansion and other tasks.
Macro processor uses three main data structure:-
1. Definition table (DEF TAB) :-
• Stores the macro definition including macro prototype and
macro body.
• Comment lines are omitted.
• References to the macro instruction parameters are
converted to a positional notation for efficiency in
substituting arguments.
35
Concept of Single pass macro Processor

2. NAMTAB:-
• Stores macro names.
• Serves as an index to DEFTAB.
• Pointers to the beginning and the end of the macro definition
(DEFTAB).
3. ARGTAB:-
• Stores the arguments of macro invocation according to their
positions in the argument list.
• As the macro is expanded, arguments from ARGTAB are
substituted for the corresponding parameters in the macro body.
36

37
ALGORITHM OF SINGLE PASS MACRO PROCESOOR:-
•Initialization:
•MDT: Empty initially.
•MNT: Empty initially.
•Symbol Table: Empty initially.
•Read Input Line:
•Fetch the next line from the source code.
•Process Macro Definition:
•Identify Definition: Check if the line starts with a macro definition keyword (e.g., MACRO).
•Store Definition:
•Macro Name Table (MNT): Store the macro name and its starting location in MDT.
•Macro Definition Table (MDT): Store the macro body.
•End of Macro: Continue reading lines until the END directive or end of macro definition.
•Process Macro Invocation:
•Identify Invocation: Check if the line contains a macro invocation.
•Lookup: Find the macro definition from MNT.
•Expand:
•Parameter Substitution: Replace formal parameters with actual arguments.
•Insert Expanded Code: Replace the macro invocation line with the expanded code.
•Update Symbol Table: Add any new symbols introduced by the macro.
•Process Normal Code:
•Directly process any lines that are not macro definitions or invocations.
•Repeat:
•Continue until the entire source code has been processed.
•Output:
•Produce the final output with all macros expanded, ready for further processing or assembly.

A two-pass macro processor is an assembler designed to handle macros in two
distinct stages, or "passes," over the source code. This approach is used to ensure
that all macro definitions are correctly expanded and that macro invocations are
appropriately processed.
Pass 1: Definition and Cataloging
Purpose:
• The first pass identifies all macro definitions and macro invocations. It records
macro definitions and their locations and prepares for the macro expansion in
the second pass.
Pass 2: Expansion and Final Assembly
Purpose:
• The second pass replaces the macro placeholders in the intermediate code
with the actual expanded code from the MDT, taking into account the
parameter values recorded in Pass 1.
38
Design of Two pass macro Processor

Pass-1 :
◦ Recognizes Macro Definition
◦ Stores Macro Instruction Definitions
Pass-2 :
◦ Recognizes Macro Calls
◦ Expands calls and substitute actual arguments
8/2/2024 39

Pass-1 Data structures/ programs :
◦ Source program with macro definitions and macro calls
◦ Output file without macro definitions & with macro calls
◦ Macro Definition Table (MDT):-
Purpose: Stores the actual definitions of macros.
◦ Macro Name Table (MNT):-
Purpose: Maps macro names to their definitions in MDT.
◦ Argument List Array (ALA) :-
Purpose: Stores information about macro parameters and their values.
◦ Macro Definition Table Counter (MDTC) :-
MDTC is used to indicate the next available entry in the MDT.
◦ Macro Name Table Counter (MNTC):-
MNTC is used to indicate the next available entry in the MNT.
40

Pass-2 Data structures/programs :
◦ Input file without macro definitions & with macro calls
◦ Expanded output file without macro definitions & macro calls (Free from Macro)
◦ Refers Macro Definition Table (MDT) created by Pass-1
◦ Refers Macro Name Table (MNT) created by Pass-1
◦ Argument List Array (ALA) to map formal parameters with actual
◦ Macro Definition Table Pointer (MDTP):
-MDTP is used to indicate the next line of text to be used during macro
expansion.
41

43
Pass 1 Flowchart of 2 pass macro processor

45
Pass 2 Flowchart of 2 pass macro processor

Q). Justify which data structures are implemented at that time of
processing Macro definition, Macro call and Macro Expansion inn 2
pass macro processor.
1. Processing Macro Definition:-
Macro Definition Table (MDT):
◦ Justification: MDT is essential for storing macro definitions so that they
can be referenced and expanded during the second pass.
Macro Name Table (MNT):
◦ Justification: MNT helps in quickly locating the macro definition in MDT
during the second pass.
Argument List Array (ALA):
◦ Justification: ALA is used to keep track of actual arguments supplied
during macro calls, which will be substituted into the macro body
during expansion.
46

2. Processing Macro Call:-
Macro Name Table (MNT):
o Justification: MNT is used to quickly find the macro definition in MDT
when a macro call is encountered. It links the macro name to its
definition location.
Argument List Array (ALA):
◦ Justification: PT is used to capture the arguments provided in the
macro call, which will later be substituted into the macro definition
during the expansion phase.
Intermediate Code Listing:
◦ Justification: The intermediate code listing helps in maintaining the
structure of the source code with markers for where macros are
invoked.
47

3. Processing Macro Expansion:-
Macro Definition Table (MDT):
Justification: MDT is used to fetch the macro body, which will be modified by
substituting parameters from PT.
Argument List Array (ALA):-
Justification:- ALA is used to replace argument placeholder in macro
body with actual argument . This ensures macro is expanded
correctly with given parameters.
Intermediate Code Listing:-
Justification:- The Intermediate code listing is updated with expanded
macro code, producing finally assembly code or machine code.This
structure is important for producing correct final output.
48

Formats of Data Structures
MNTC Macro Name MDTC
1
● Macro Name Table (MNT)
ADDS 1
2
.
.
8/2/2024 49

Formats of Data Structures (Cont..)
MDTC Macro Definition Instruction Entry (80 bytes per entry)
1
:
:
:
● Macro Definition Table (MDT)
& Lab ADDS &A1, &A2
2 #0 A 1, #1
3 A 1, #2
4 MEND
5

Formats of Data Structures (Cont..)
Index Formal
Arguments
Actual
Arguments
:
:
● Arguments List Array (ALA)
8/2/2024 51
0 &Lab
1 &A1
2 &A2
3
-
-
-

Pass1
MDTC 1
🡨
MNTC 1
🡨
Read Next Source Card
MACRO
Pseudo
op ?
Enter Macro Name &
Current value of MDTC in
MNT
MNTC MNTC+1
🡨
Prepare ALA
Prepare macro name card
and add into MDT
MDTC MDTC+1
🡨
Substitute index Notation
for Arguments
Enter Line into MDT
MDTC MDTC+1
🡨
MEND
Pseudo
op ?
Write copy of source card
END
Pseudo
op ?
GO TO
PASS2
No
Yes
Yes
No
No
Yes
Add MEND in MDT,
MDTC MDTC+1
🡨
53
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Source Code :
MAC START 100
MACRO
&A0 ADD1 &A1, &A2, &A3
&A0 L 1, &A1
L 2, &A2
AR 1, 2
MUL 1, &A3
ST N, 1
MEND
MACRO
SUB &P1, &P2
L 1, &P1
S 1, &P2
ST 2, 1
MEND
TOTAL EQU 5
L 1,D1
SR 2,2
A 1,=F’5’
ADD1 LOOP1, D1, D2, D3
ST 2, 1
AR TOTAL, 2
SUB X, Y
BR 14
D1 DC F’3’
D2 DC F’45’
D3 DC F’21’
X DC F’10’
Y DC F’20’
END
Intermediate Code after pass1:
MAC START 100
TOTAL EQU 5
L 1, D1
SR 2, 2
A 1, =F’5’
ST 2, 1
AR TOTAL, 2
SUB X, Y
BR 14
D1 DC F’3’
D2 DC F’45’
D3 DC F’21’
X DC F’10’
Y DC F’20’
END
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35
MACRO
&A0 ADD1 &A1, &A2, &A3
&A0 L 1, &A1
L 2, &A2
AR 1, 2
MUL 1, &A3
ST N, 1
MEND
MACRO
SUB &P1, &P2
L 1, &P1
S 1, &P2
ST 2, 1
MEND
47

MNTC Macro
Name
MDTC
1
MDTC Macro Card
1
Macro Definition Table :
Macro Name Table :
Ind
ex
Formal Args Actual
Args
1
2
3
4
5
6
Argument List Array :
55
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34

MNTC Macro
Name
MDTC
1 ADD1 1
2
MDTC Macro Card
1 &A0 ADD1 &A1, &A2, &A3
2
Macro Name Table :
Index Formal
Args
1 &A0
2 &A1
3 &A2
4 &A3
56
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Actual
Args.
34

MNTC Macro
Name
MDTC
1 ADD1 1
2
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3
Macro Name Table :
Ind
ex
Argument Actual
Args.
1 &A0
2 &A1
3 &A2
4 &A3
5
57
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34

MNTC Macro
Name
MDTC
1 ADD1 1
2
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5
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MNTC Macro
Name
MDTC
1 ADD1 1
2
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1, 2
5 MUL 1 , #4
6
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5
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MNTC Macro
Name
MDTC
1 ADD1 1
2
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5
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MNTC Macro
Name
MDTC
1 ADD1 1
2
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7 MEND
8
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5
61
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MNTC Macro
Name
MDTC
1 ADD1 1
2 SUB 8
3
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7 MEND
8 SUB &P1, &P2
9
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5 &P1
6 &P2
62
8/2/2024

MNTC Macro
Name
MDTC
1 ADD1 1
2 SUB 8
3
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7 MEND
8 SUB &P1, &P2
9 L 1, #5
10
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5 &P1
6 &P2
63
8/2/2024

MNTC Macro
Name
MDTC
1 ADD1 1
2 SUB 8
3
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7 MEND
8 SUB &P1, &P2
9 L 1, #5
10 S 1, #6
11
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5 &P1
6 &P2
64
8/2/2024

MNTC Macro
Name
MDTC
1 ADD1 1
2 SUB 8
3
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7 MEND
8 SUB &P1, &P2
9 L 1, #5
10 S 1, #6
11 ST 2, 1
12
Macro Name Table :
Index Argument
1 &A0
2 &A1
3 &A2
4 &A3
5 &P1
6 &P2
65
8/2/2024

MNTC Macro
Name
MDTC
1 ADD1 1
2 SUB 8
3
MDTC Macro Card
1 &A0 ADD1 &A1,&A2,&A3
2 #1 L 1, #2
3 L 2, #3
4 AR 1,2
5 MUL 1 , #4
6 ST N,1
7 MEND
8 SUB &P1, &P2
9 L 1, #5
10 S 1, #6
11 ST 2, 1
12 MEND
13
Macro Name Table :
Index Argument Actual
args
1 &A0
2 &A1
3 &A2
4 &A3
5 &P1
6 &P2
66
8/2/2024

PASS 2
Read Next Source card
Search MNT for matching operation
code
MDTP MDT Index from
🡨
MNT Entry
Set Up ALA
MDTP MDTP +1
🡨
Get Line From MDT
Substitute arguments from Macro
Call
Macro Name
Found ?
MEND Pseudo
Op?
Write Expanded Source Card
Write Expanded Source Card
END Pseudo
Op?
Supply expanded source file to
Assembler Processing
No
Yes
No
Yes
Yes
No
67
8/2/2024
34

In
de
x
Formal Actual
1 &A0 LOOP
1
2 &A1 D1
3 &A2 D2
4 &A3 D3
5 &P1 X
6 &P2 Y
Expanded Source Code :
MAC START 100
TOTAL EQU 5
L 1, D1
SR 2, 2
A 1, =F’5’
LOOP1 L 1, D1
L 2, D2
AR 1, 2
MUL 1, D3
ST N, 1
ST 2, 1
AR TOTAL, 2
L 1, X
S 1, Y
ST 2, 1
BR 14
D1 DC F’3’
D2 DC F’45’
D3 DC F’21’
X DC F’10’
Y DC F’20’
END
Intermediate Code after pass1
(input file for pass 2):
MAC START 100
TOTAL EQU 5
L 1, D1
SR 2, 2
A 1, =F’5’
ST 2, 1
AR TOTAL, 2
SUB X, Y
BR 14
D1 DC F’3’
D2 DC F’45’
D3 DC F’21’
X DC F’10’
Y DC F’20’
END
68
8/2/2024
ALA
MDTP= 1, 2, 3, 4, 5, 6, 7 for ADD1
MDTP= 8, 9, 10, 11, 12, 13 for SUB

Macro calls within Macros
69
8/2/2024

Macro Calls Within Macro
MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &ARG1, &ARG2, &ARG3
ADD1 &ARG1 ………………
ADD1 &ARG2 ……………… macro call in macro definition
ADD1 &ARG3 ………………
MEND
70
8/2/2024

▪To handle macro call within macros, macro processor has to work
recursively.
▪It uses stack to keep track of unfinished computations.
▪For every macro call, separate stack frame is created.
▪SP:- It is a Stack Position. It indicates the position or stack frame no. at the
top of the stack. i.e. It is the beginning position of current stack frame.
▪S(SP):- It refers to the beginning of the current stack frame. (i.e. the
contents of the stack at position “SP”.
▪MDLC:- Macro Definition Level Counter
▪N:- no. of arguments in macro call along with label argument.
71
8/2/2024
Macro Calls Within Macro (Cont….)

Macro Processor
MDLC 0
🡨
N 0
🡨
SP -1
🡨
Search MNT for
match with
operation code
S(SP+1) MDT Index
🡨
from MNT entry
SP SP+N+2
🡨
S(SP+N+2) SP
🡨
Set up macro call ALA
in S(SP+2)
…..S(SP+N+1) Where
N= Total no. of
arguments in call
READ *
MACRO
Pseudo
op?
READ *
Enter macro name
and current value
of MDTC in MNT
Prepare macro
definition ALA
Enter macro name
card into MDT
MDLC MDLC+1,
🡨
MNTC=MNTC+1
READ *
Substitute index notation for
argument in definition
Enter line into MDT, MDTC=MDTC+1
MDLC MDLC+1
🡨
MDLC MDLC-1
🡨
MDLC
=0?
Write into
Expanded Source
file
Supply Expanded
source file to
assembler
processing
Macro
Name
found ?
MACRO
Pseudo
op?
MEND
Pseudo
op?
END
Pseudo
op?
B
B
B
A
A A
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Yes
Macro Calls Within Macro Definition
72
8/2/2024

READ
Subroutine
SP=-1
MDLC
=0?
AIF or
AGO ?
MEND
Pseudo op
?
Read Next
source card
from input file
Return to main
processing
Increment MDT
pointer to next entry
S(SP+1) S(SP+1)+1
🡨
Get next card from
MDT ; Pointer is
S(SP+1)
Substitute arguments
from macro call
S(SP+2) ….S(SP+N+1)
N SP-S(SP)-2
🡨
SP S(SP)
🡨
Process AIF or AGO
set new value to
MDT Pointer ,
S(SP+1)
C
C
No
No
No
No
Yes
Yes
Yes, terminate macro call; pop back
to previous stack frame
Yes
Macro Calls Within Macro Definition (READ
Subroutine)
Macro definition within macro call
73
8/2/2024

-1
:
:
:
S(SP)
S(SP+1)
S(SP+2)
S(SP+3)
:
:
:
:
S(SP+1+N)
:
:
:
Previous Frame(s)
Available for next frame
🡨 Old SP
🡨 MDT Pointer for this frame
🡨 0th
(label) argument
🡨 1st
argument
🡨 (N-1)th argument
:
:
:
:
Macro call ALA
SP…………………….
SP+1 ……………….
SP+2 ……………….
SP+3 ……………….
:
:
:
:
(SP+2)+(N-1) …..
Stack Organization N=No. of arg. On macro line
SP = current value of stack pointer
S(m) =content of mth
position on stack
74
8/2/2024

-1
-1
6
Blank
D1
D2
D3
-1
7
Blank
D1
D2
D3
1
1
Blank
D1
SP=-1
SP=1
SP=7
S(1)
S(2)
S(3)
S(4)
S(5)
S(6)
index
S(1)
.
.
.
.
.
S(7)
S(8)
S(9)
S(10)
.
.
Current stack
frame
previous stack
frame
Macro Call:- ADD1 D1
Call:- ADDS D1, D2, D3
S(1)
75
8/2/2024

MACRO
ADD1 &ARG
L1,&ARG
A 1,=F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1
MNTC NAME MDTC
1
INDEX ARGUME
NT
76
8/2/2024

MACRO
ADD1 &ARG
L1,&ARG
A 1,=F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1
MNTC NAME MDTC
1
INDEX ARGUME
NT
77
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1
INDEX ARGUME
NT
MNTC NAME MDTC
1 ADD1 1
2
78
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
79
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0,1
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1 ADD1 &ARG
2
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
80
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0,1
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
81
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0,1
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
82
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0,1
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
83
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
84
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6
85
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6
86
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6
87
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0, 1
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7
88
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0, 1
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8
89
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0, 1
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9
90
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0, 1
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10
91
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
92
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNT
C
NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2
3
4
5
6
7
8
9
10
11
12 93
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1, 1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2
3
4
5
6
7
8
9
10
11
12 94
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0
🡪
SP -1, 1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 6
3
4
5
6
7
8
9
10
11
12
95
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0,4
🡪
SP -1,1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 6
3 Blk
4 D1
5 D2
6 D3
7
8
9
10
11
12
96
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0,4
🡪
SP -1, 1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7
8
9
10
11
12 97
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0, 4
🡪
SP -1, 1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7
8
9
10
11
12
ADD1 D1
98
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0, 4
🡪
SP -1, 1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8
9
10
11
12 99
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0, 4
🡪
SP -1, 1, 7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8
9
10
11
12
100
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4
🡪
SP -1,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 1
9
10
11
12
101
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2
🡪
SP -1,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 1
9 Blk
10 D1
11
12
102
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2
🡪
SP -1,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 2
9 Blk
10 D1
11
12
L 1,D1
103
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2
🡪
SP -1,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 3
9 Blk
10 D1
11
12
L 1,D1
A 1,=F’1’
104
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2
🡪
SP -1,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 4
9 Blk
10 D1
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
105
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4
🡪
SP -1,1,7,1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D1
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
106
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4
🡪
SP -1,1,7,1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D1
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
ADD1 D2
107
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2
🡪
SP -1,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 1
9 Blk
10 D2
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
ADD1 D2
108
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2
🡪
SP -1,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 2
9 Blk
10 D2
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
109
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2
🡪
SP -1,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 3
9 Blk
10 D2
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
110
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2
🡪
SP -1,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 4
9 Blk
10 D2
11
12
L 1, D1
A 1, =F’1’
ST 1, D1
L 1, D2
A 1, =F’1’
ST 1, D2
111
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,
🡪
SP -1,1,7,1,7,1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D2
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
112
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4
🡪
SP -1,1,7,1,7,1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 9
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D2
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
ADD1 D3
113
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2
🡪
SP -1,1,7,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 8
3 Blk
4 D1
5 D2
6 D3
7 1
8 1
9 Blk
10 D3
11
12
L 1, D1
A 1, =F’1’
ST 1, D1
L 1, D2
A 1, =F’1’
ST 1,D2
ADD1 D3
114
8/2/2024

MACRO
ADD1 &ARG
L 1, &ARG
A 1, =F’1’
ST 1, &ARG
MEND
MACRO
ADDS &A1, &A2, &A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1, D2, D31
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2
🡪
SP -1,1,7,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1, #1
3 A 1, =F’1’
4 ST 1, #1
5 MEND
6 ADDS &A1, &A2, &A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 2
9 Blk
10 D3
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
L 1,D3
115
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2
🡪
SP -1,1,7,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 3
9 Blk
10 D3
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
L 1,D3
A 1,=F’1’
116
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2
🡪
SP -1,1,7,1,7,1,7
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 4
9 Blk
10 D3
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
L 1,D3
A 1,=F’1’
ST 1,D3
117
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2,4
🡪
SP -1,1,7,1,7,1,7,1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 7
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D3
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
L 1,D3
A 1,=F’1’
ST 1,D3
118
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2,4,0
🡪
SP -1,1,7,1,7,1,7,1,-1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 10
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D3
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
L 1,D2
A 1,=F’1’
ST 1,D2
119
8/2/2024

MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F’1’
ST 1,&ARG
MEND
MACRO
ADDS &A1,&A2,&A3
ADD1 &A1
ADD1 &A2
ADD1 &A3
MEND
ADDS D1,D2,D3
:
:
END
MDLC 0
🡪
N 0,4,2,4,2,4,2,4,0
🡪
SP -1,1,7,1,7,1,7,1,-1
🡪
INDEX ARGUME
NT
1 &ARG
2 &A1
3 &A2
4 &A3
MNTC NAME MDTC
1 ADD1 1
2 ADDS 6
3
MNT
C
DEFINITION
1 ADD1 &ARG
2 L 1,#1
3 A 1,=F’1’
4 ST 1,#1
5 MEND
6 ADDS &A1,&A2,&A3
7 ADD1 #2
8 ADD1 #3
9 ADD1 #4
10 MEND
11
1 -1
2 10
3 Blk
4 D1
5 D2
6 D3
7 1
8 5
9 Blk
10 D3
11
12
L 1,D1
A 1,=F’1’
ST 1,D1
L 1,D2
A 1,=F’1’
ST 1,D2
L 1,D2
A 1,=F’1’
ST 1,D2
END
120
8/2/2024

Single Pass Macro Processor
121
8/2/2024
(Macro Definition Within Macro)

Example:
---------
---------
MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0, 4
BAL 1, *+8
DC A(&Y)
L 15, =V(&SUB)
BALR 14, 15
MEND
MEND
------
DEFINE COS
COS AR Macro call
Outer macro definition
inner
macro
definition
122
8/2/2024

MDLC=0?
A
No
One Pass
Macro
Processor
MDTC 1
🡨
MNTC 1
🡨
MDI “OFF”
🡨
MDLC 0
🡨
READ*
Search MNT for match
with operation code
Macro name
found?
MDI “ON”
🡨
MDTP MDT Index from
🡨
MNT entry
Set up macro call ALA
MACRO name
found?
READ*
Enter macro name and
current value of MDTC in
MNT
MNTC MNTC+1
🡨
Prepare macro definition
ALA
Enter macro name card
into MDT
MDTC MDTC+1
🡨
MDLC MDLC+1
🡨
READ*
Substitute Index
Notation for
Arguments in
definition
Enter line into MDT
MDTC MDTC+1
🡨
MACRO
pseudo-op?
MEND
pseudo-op?
MDLC 🡨
MDLC+1
MDLC 🡨
MDLC - 1
Write into expanded source
card
END
pseudo-
op?
Supply expanded
source file to
assembler processing
A
A
Yes
No
Yes
No
No
No
No
Yes
Yes
Yes
Yes
8/2/2024 123

READ
Subroutine
MDI=“OFF”
?
Read next source card
from i/p file
Return to Main
Processing
Increment MDT pointer to
next entry
MDTO +MDTP+1
🡨
Get Next card
from MDT
Substitute argument
from macro call
MEND
pseudo
op?
AIF or
AGO
Process AIF or AGO,
Set new value to
MDTP
MDLC=
0?
MDI “OFF”
🡨
Yes
Yes Yes
Yes
No
No
No
No
124
8/2/2024

Source Code
MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=1
MNTC=1
MDI=“OFF”
MDLC=0
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
--------------------------------------------
MNT
-----------------------------------------------
MNTC NAME MDTC
-----------------------------------------------
-----------------------------------------------
8/2/2024 125

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=1
MNTC=1
MDI=“OFF”
MDLC=0
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
--------------------------------------------
MNT
-----------------------------------------------
MNTC NAME MDTC
-----------------------------------------------
-----------------------------------------------
Reading Next source card due to Macro keyword
8/2/2024 126

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=2
MNTC=2
MDI=“OFF”
MDLC=1
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
Reading Next source card after entering line into MDT
8/2/2024 127

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=3
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 128

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=4
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 129

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=5
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 130

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=6
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 131

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=7
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 132

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=8
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 133

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=9
MNTC=2
MDI=“OFF”
MDLC=2
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 134

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=10
MNTC=2
MDI=“OFF”
MDLC=1
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
8/2/2024 135

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=11
MNTC=2
MDI=“OFF”
MDLC=0
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
Reading Next source card after entering line into MDT & MDLC=0
8/2/2024 136

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=11
MNTC=2
MDI=“OFF”
MDLC=0
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
Reading Next source card AND write to output file
EXPANDED SOURCE FILE
--------------------------------------------
PROG START
8/2/2024 137

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=11
MNTC=2
MDI=“OFF”
MDLC=0
MDTP=
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 &SUB
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10 MEND
11
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 138

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=11
MNTC=2
MDI=“ON”
MDLC=0
MDTP=1
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
Reading Next source card i.e. call to outer MACRO
--------------------------------------------
PROG START
SR 1, 1
8/2/2024 139

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=11
MNTC=2
MDI=“ON”
MDLC=0
MDTP=2
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0 &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10 MEND
11
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2
-----------------------------------------------
Reading Next source card which expansion of MACRO DEFINE
--------------------------------------------
PROG START
SR 1,1
8/2/2024 140

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=12
MNTC=3
MDI=“ON”
MDLC=1
MDTP=3
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 141

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=13
MNTC=3
MDI=“ON”
MDLC=1
MDTP=4
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 142

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=14
MNTC=3
MDI=“ON”
MDLC=1
MDTP=5
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 143

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=15
MNTC=3
MDI=“ON”
MDLC=1
MDTP=6
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 144

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=16
MNTC=3
MDI=“ON”
MDLC=1
MDTP=7
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 145

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=17
MNTC=3
MDI=“ON”
MDLC=1
MDTP=8
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
8/2/2024 146

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=9
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Reading Next source card which expansion of MACRO DEFINE & MDLC=0
--------------------------------------------
PROG START
SR 1,1

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“OFF”
MDLC=0
MDTP=10
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Expansion of Macro Define completed
--------------------------------------------
PROG START
SR 1,1
8/2/2024 148

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“OFF”
MDLC=0
MDTP=10
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 &Y
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
AR 1,4
8/2/2024 149

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=11
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Reading Next source card which is call to MACRO COS
--------------------------------------------
PROG START
SR 1, 1
AR 1, 4
8/2/2024 150

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=12
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L 15,
=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Expansion of MACRO COS started & written to expanded source file
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
8/2/2024 151

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=13
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L 15,
=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
8/2/2024 152

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=14
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15, =V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
8/2/2024 153

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=15
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
L 15,=V(COS)
8/2/2024 154

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“ON”
MDLC=0
MDTP=16
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
L 15,=V(COS)
BALR 14,15
8/2/2024 155

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“OFF”
MDLC=0
MDTP=17
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Expansion of MACRO COS completed & setting MDI to OFF
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
L 15,=V(COS)
BALR 14,15
8/2/2024 156

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“OFF”
MDLC=0
MDTP=17
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Reading Next source card & entering line into expanded source file
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
L 15,=V(COS)
BALR 14,15
L 1,X
8/2/2024
157

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“OFF”
MDLC=0
MDTP=17
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Reading Next source card & entering line into expanded source file
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
L 15,=V(COS)
BALR 14,15
L 1,X
END
8/2/2024 158

MACRO
DEFINE &SUB
MACRO
&SUB &Y
CNOP 0,4
BAL 1,*+8
DC A(&Y)
L 15,=V(&SUB)
BALR 14,15
MEND
MEND
PROG START
SR 1,1
DEFINE COS
AR 1,4
COS AR
L 1,X
END
MDTC=18
MNTC=3
MDI=“OFF”
MDLC=0
MDTP=17
ALA
--------------------------------
INDEX ARG
--------------------------------
#0 COS
#1 AR
---------------------------------
MDT
---------------------------------------------
MDTC DEF
---------------------------------------------
1 DEFINE &SUB
2 MACRO
3 #0/COS &Y
4 CNOP 0,4
5 BAL 1,*+8
6 DC A(&Y)
7 L 15,=V(#0)
8 BALR 14,15
9 MEND
10 MEND
11 COS &Y
12 CNOP 0,4
13 BAL 1,*+8
14 DC A(#1)
15 L
15,=V(COS)
16 BALR 14,15
17 MEND
18
---------------------------------------------
MNT
-----------------------------------------------
MNTC NAME
MDTC
-----------------------------------------------
1 DEFINE 1
2 COS 11
3
-----------------------------------------------
Output Expanded source file is ready (END of processing)
🡪
--------------------------------------------
PROG START
SR 1,1
AR 1,4
CNOP 0,4
BAL 1,*+8
DC A(AR)
L 15,=V(COS)
BALR 14,15
L 1,X
END
8/2/2024 159

Compiler
Definition : Compiler is a program which takes one language (source
program) as input and translates it into an equivalent another language
(target program).
 During this process of translation if some errors are encountered
then compiler displays them as error messages.
 The compiler takes a source program as higher level languages such
as C, PASCAL, FORTRAN and converts it into low level language or a
machine level language such as assembly language.
Compiler
SOURCE PROGRAM
( Normally a program written
in a high-level programming
language)
TARGET PROGRAM
( Normally the equivalent
program in machine code –
relocatable object file)
Error
Messages
160
8/2/2024
Syllabus

Let’s have a look at, what
happens inside Black Box
161
8/2/2024

Target Program
Source Program
Lexical Analyzer
1
Syntax Analyzer
2
Semantic Analyzer
3
Intermediate Code
Generator
4
Code Optimizer
5
Code Generator
6
Symbol-table
Manager
Error Handler
Stream of
characters
Parse/syntax
tree
Annotated
tree
Intermediate
code
Optimized Intermediate
code
General Model of Compiler
Analysis/
Language
Dependent/
M/C
Independent
Phases
Synthesis/
Language
Independe
nt/ M/C
Dependent
Phases
163
8/2/2024

Various phases in which compilation is done are as follows –
1. Lexical Analysis :-
 The lexical analysis is also called scanning.
 It the phase of compilation in which the complete source code is
scanned and your source program is broken up into group of strings
called token.
 For example if some assignment statement in your source code is as
follows, total = count + rate * 10
 Then in lexical analysis phase this statement is broken up into series
of tokens as :- 1) The Identifier total = (Id1) 2) The assignment sign
3)The identifier count = (Id2) 4) The Plus sign 5) The Identifier rate =
(Id3) 6) The multiplication sign 7) The constant number 10
 The blank characters which are used in the programming statement
are eliminated during the lexical analysis phase.
164
Phases Of Compiler

2. Syntax Analysis :
• The syntax analysis is also called parsing.
• In this phase the tokens generated by the lexical analyser are
grouped together to form a hierarchical structure called parse tree
or syntax tree
• For the expression total = count + rate*10 parse tree can be
generated as
165

3. Semantic Analysis:-
 Once the syntax is checked in the syntax analyser phase the next
phase i.e. the semantic analysis determines the meaning of the
source string.
 For ex. the example meaning of source string means matching of
parenthesis in the expression, or matching of if ...else statements or
performing arithmetic operations of expressions that are type
compatible, or checking the scope of operation.
166

4. Intermediate Code Generation:-
 The intermediate code is a kind of code which is easy to generate
and this code can be easily converted to target code.
 Intermediate code in three address code form. This is like assembly
language.
 The three address code consists of instructions each of which has at
the most three operands. For example,
t1 : = int to float (10)
t2: = id3 * t1
t3: = id2 + t2
id3 : = t3
167

5. Code Optimization:-
 The code optimization phase attempts to improve the intermediate
code.
 This is necessary to have a faster executing code or less
consumption of memory.
 Thus by optimizing the code the overall running time of the target
program can be improved
 For ex. In this phase total=count + rate*10 will optimize like below
after intermediate code generation:-
t1=id3 * 10.0
id1 = id2 + t1
168

6. Code Generation:-
In code genration phase the target code gets generated. The
intermediate code instructions are translated into sequence of machine
instructions.
MOV id3, R1
MUL #10.0, R1
MOV id2, R2
ADD R2, R1
MOV R1, total
169

The Structure of a Compiler
170
Scanner
[Lexical Analyzer]
Parser
[Syntax Analyzer]
Semantic Process
[Semantic analyzer]
Code Generator
[Intermediate Code Generator]
Code Optimizer
Tokens
Parse tree
Abstract Syntax Tree w/ Attributes
Non-optimized Intermediate Code
Optimized Intermediate
Code
Code Generator
Target machine
code
8/2/2024

Symbol Table
▪Compiler uses symbol table to keep track of scope and binding
information about names.
▪Symbol table is searched every time when a name is encountered in
source text.
▪Changes occur in symbol table if a new name or new info about existing
name is discovered.
▪Two symbol table mechanisms are presented generally, linear list, hash
tables.
▪Compiler should grow S.T. dynamically at compile time or the symbol table
can be kept fixed.
171
8/2/2024

The Symbol Table
▪When identifiers are found, they will be entered into a symbol table, which will hold
all relevant information about identifiers.
▪When the symbol is first encountered by the lexer, we do not yet know the scope.
▪That is determined later by the parser.
▪This information will be used later by the semantic analyzer and the code generator.
Lexical
Analyzer
Semantic
Analyzer
Code
Generator
Symbol
Table
Syntax
Analyzer
172
8/2/2024

Symbol Table Entries
We will store the following information about identifiers.
▪The name (as a string).
▪The data type and value.
▪The block level.
▪Its scope (global, local, or parameter).
▪Its offset from the base pointer (for local variables and
parameters only).
173
8/2/2024

Interpreter
It is a translator (language processor) which directly
executes operations specified in source program on input
supplied by user.
Interpreter
SOURCE PROGRAM
Output
Input
174
8/2/2024

Interpreter vs Compiler
Interpreter Compiler
Translates program by one statement at a
time.
Scans the entire program and translates it as
a whole into machine code.
It takes less amount of time to analyze the
source code but the overall execution time
is slower.
It takes large amount of time to analyze the
source code but the overall execution time
is comparatively faster.
No intermediate object code is generated,
hence are memory efficient.
Generates intermediate object code which
further requires linking, hence requires
more memory.
Continues translating the program until the
first error is met, in which case it stops.
Hence debugging is easy.
It generates the error message only after
scanning the whole program. Hence
debugging is comparatively hard.
Programming language like Python, Ruby
use interpreters.
Programming language like C, C++ use
compilers.
176
8/2/2024

Case Study- GNU m4 Macro
Processor
177
8/2/2024
▪m4 is a macro processor, it copies its input to the output, expanding macros as it goes.
▪Macros are either built-in or user-defined, and can take any number of arguments.
▪Besides just doing macro expansion, m4 has built-in functions for including named files in UNIX commands,
doing integer arithmetic, manipulating text in various ways, recursion, etc.
▪m4 can be used either as a front-end to a compiler, or as a macro processor in its own right.
▪The most popular GNU Autoconf pre-requires GNU m4 for generating the ’configure’ scripts.
▪While these people will not themselves program in m4. GNU m4is mostly compatible with the System V,
Release 3 version, except for some minor differences.
▪A General Purpose Macro generator (GPM) an important ancestor of m4 . m4 is mostly SVR4 compatible.

Case Study- GNU m4 Macro
Processor
178
8/2/2024
The format of the m4command is:
m4 [option...] [macro-definitions...] [input-file...]
m4 --def foo --debug a is equivalent to 🡪
m4 --define=foo --debug= -- ./a

1) John Donovan, “Systems Programming”, McGraw Hill, ISBN 978-0--07-460482-3
2) Dhamdhere D., "Systems Programming and Operating Systems", McGraw Hill, ISBN 0 - 07 - 463579 – 4
3) https://www.gnu.org/software/m4/manual/m4.html#Syntax
Ebooks:
▪ https://www.elsevier.com/books/systems-programming/anthony/978-0-12-800729-7
▪ https://www.kobo.com/us/en/ebook/linux-system-programming-1
▪ https://www.e-booksdirectory.com/details.php?ebook=9907
MOOCs Courses Links:
▪ nptel video lecture link: https://nptel.ac.in/courses/106/105/106105214/
▪ https://onlinecourses.nptel.ac.in/noc19_cs50/preview
▪ https://www.udemy.com/course/system-programming/
8/2/2024 179
References

SPOS UNIT 2 MACRO NOTES SPOS UNIT 2 MACRO NOTESSPOS UNIT 2 MACRO NOTESSPOS UNIT 2 MACRO NOTES

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