HP2100A Assembler Reference Manual

CHAPTER 1 GENERAL DESCRIPTION 1-1
1.1 Assembly Processing 1-1
1.2 Symbolic Addressing 1-1
1.3 Program Relocation 1-3
1.4 Program Location Counters 1-3
1.5 Assembly Options 1-4

CHAPTER 2 INSTRUCTION FORMAT 2-1
2.1 Statement Characteristics 2-1
Field Delimiters 2-1
Character Set 2-1
Statement Length 2-3
2.2 Label Field 2-3
Label Symbol 2-3
Asterisk 2-5
2.3 Opcode Field 2-5
2.4 Operand Field 2-5
Symbolic Terms 2-6
Numeric Terms 2-7
Asterisk 2-5 ?
Expression Operators 2-7
Evaluation of Expressions 2-8
Expression Terms 2-9
Absolute and Relocatable
Expressions 2-9
Literals 2-11
Indirect Addressing 2-12
Base Page Addressing 2-13
Clear Flag Indicator 2-13
2.5 Comments Field 2-13

CHAPTER 3 MACHINE INSTRUCTIONS 3-1
3.1 Memory Reference 3-1
Jump and Increment-Skip 3-2
Add, Load, and Store 3-2
Logical Operations 3-3
3.2 Register Reference 3-4
Shift-Rotate Group 3-4
No-Operation Instructions 3-5
Alter-Skip Group 3-6
3.3 Input/Output, Overflow and Halt 3-7
Input/Output 3-8
Overflow 3-9
Halt 3-10
3.4 Extended Arithmetic Unit 3-11
3.5 Floating-Point Instructions 3-13

CHAPTER 4 PSEUDO INSTRUCTIONS 4-1
4.1 Assembler Control 4-1
NAM ORG 4-1
ORR 4-2
ORB 4-3
IFN IFZ 4-4
REP 4-6
END 4-7
4.2 Object Program Linkage 4-8
COM 4-8
ENT EXT 4-10
4.3 Address and Symbol Definition 4-11
DEF 4-12
ABS EQU 4-15
4.4 Constant Definition 4-17
ASC 4-17
DEC 4-18
DEX 4-20
OCT 4-22
4.5 Storage Allocation 4-23
BSS 4-23
4.6 Assembly Listing Control 4-23
UNL 4-23
LST SUP UNS 4-24
SKP SPC HED 4-25
4.7 Arithmetic Subroutine Calls 4-26
MPY DIC FMP FDV 4-26
FAD FSB DLD DST 4-27

CHAPTER 5 ASSEMBLER INPUT AND OUTPUT 5-1
5.1 Control Statement 5-1
A R B L 5-1
T H Z F 5-2
5.2 Source Program 5-3
5.3 Binary Output 5-3
5.4 List Output 5-3

APPENDIX A HP CHARACTER SET A-1
BINARY CODED DECIMAL FORMAT A-2
Kennedy 1406/1506 ASCII -- BCD A-2
HP 2020A/B ASCII - BCD A-3

APPENDIX B ASSEMBLER INSTRUCTIONS B-1
MACHINE INSTRUCTIONS
Memory Reference B-2
Register Reference B-2
Input/Output, Overflow, and Halt B-4
Extended Arithmetic Unit B-5
PSEUDO INSTRUCTIONS
Assembler Control B-6
Object Program Linkage B-6
Address and Symbol Definition B-6
Constant Definition B-7
Arithmetic Subroutine Calls Requests B-7
Assembly Listing Control B-8

APPENDIX C ALPHABETIC LIST OF INSTRUCTIONS C-1

APPENDIX D SAMPLE PROGRAMS D-1
File Parts Update D-1
Sample Assembler Symbol
Table Output D-3
Sample Assembler List Output D-4
Calculating Distance D-9

APPENDIX E SYSTEM INPUT/OUTPUT SUBROUTINES E-1
Memory Allocation E-1
Operation and Calling Sequence:
Paper Tape Devices E-2
Register Contents E-2
Operation and Calling Sequence:
Magnetic Tape Driver E-3
Register Contents E-3
Linkage Address E-4
Magnetic Tape Operations E-4
Read E-4
Write E-5
Write End-of-File E-6
Rewind E-6
Position E-6
Rewind/Standby E-7
Gap E-7
Status E-7
Additional Linkage Addresses E-10
Buffer Storage Area E-10
Record Formats E-10
2020 7-Level Tape E-12
3030 9-Level Tape E-12
Operating and Calling Sequence:
Mark Sense Card Reader E-13
Register Contents E-13

APPENDIX F FORMATTER F-0
Calling Sequences F-0
Format Specifications F-2
Example F-3

APPENDIX G ASSEMBLY ERROR MESSAGES G-1

APPENDIX H CONSOLIDATED CODING SHEET H-1

INTRODUCTION

The Assembler and the Extended Assembler translate symbolic
source language instructions into an object program for execution
on the computer. The source language provides mnemonic machine
operation codes, assembler directing pseudo codes, and symbolic
addressing. The assembled program may be absolute or relo-
catable.

The source program may be assembled as a complete entity or it
may be subdivided into several subprograms (or a main program
and several subroutines), each of which may be assembled separ-
ately. The relocating loader loads the program and Links the
subprograms as required. The Basic Binary Loader or Basic
Binary Disc Loader loads absolute programs.

Input for the Assembler is prepared on paper tape or cards; the Assem-
bler punches the binary program on paper tape in a format acceptable
to the loader.

GENERAL DESCRIPTION

1.1 ASSEMBLY PROCESSING

The Assembler is a two pass system, or, if both punch and
list output are requested, a three pass system on a minimum
configuration. A pass is defined as a processing cycle of the
source program input.

In the first pass, the Assembler creates a symbol table from
the names used in the source statements. It also checks for
certain possible error conditions and generates diagnostic
messages if necessary.

During pass two, the Assembler again examines each state-
ment in the source program along with the symbol table and
produces the binary program and a program listing. Addition
diagnostic messages may also be produced.

If only one output device is available and if both the binary
output and list output are requested, the listing function is
deferred and performed as pass three.

When using the Assembler with a mass storage device the source
program is written on the device during the first pass; the second
pass of the source is read from the mass storage.

1.2 SYMBOLIC ADDRESSING

Symbols may be used for referring to machine instructions,
data, constants, and certain other pseudo operations. A sym-
bol represents the address for a computer word in memory.
A symbol is defined when it is used as a label for a location in
the program, a name of a common storage segment, the label
of a data storage area or constant, the label of an absolute or
relocatable value, or a location external to the program.

Through use of simple arithmetic operators, symbols may be
combined with other symbols or numbers to form an expres-
sion which may identify a location other than that specifically
named by a symbol. Symbols appearing in operand expres-
sions, but not specifically defined, and symbols that are
defined more than once are considered to be in error by the
Assembler.

1-1

[IMAGE]

HP ASSEMBLER PROCESSING

1-2

1.3 PROGRAM RELOCATION

Relocatable programs may be relocated in core by the relocating
loader; the location of the program origin and all subsequent
instructions is determined at the time the program is loaded.

A relocatable program is assembled assuming a starting
location of zero. All other instructions and data areas are
assembled relative to this zero base. When the program is
loaded, the relocatable operands are adjusted to correspond
with the actual locations assigned by the loader.

The starting locations of the common storage area and the
base page portion of the program are always established by
the loader. References to the common area are common re-
locatable. Reference to the base page portion of the program
are base page relocatable. If a program refers to the common
area or makes use of the base page via the ORB pseudo in-
struction, the program must also be relocatable.

If a program is to be relocatable, all subprograms comprising
the program must be relocatable; all memory reference
operands must be relocatable expressions or literals, or have
an absolute value of less than 100(8).

1.4 PROGRAM LOCATION COUNTERS

The Assembler maintains a counter, called the program loca-
tion counter, that assigns consecutive memory addresses to
source statements.

The initial value of the program location counter is estab-
lished according to the use of either the NAM or ORG psuedo
operation at the start of the program. The NAM operation
causes the program location counter to be set to zero for a
relocatable program; the ORG operation specifies the absolute
starting location for an absolute program.

Through use or the ORB pseudo operation a relocatable pro-
gram may specify that certain operations or data areas be
allocated to the base page. If so, a separate counter, called
the base page location counter, is used in assigning these
locations.

1-3

1.5 ASSEMBLY OPTIONS

Parameters specified with the first statement, the control
statement, define the output to be produced by the assembler: [1]

Absolute - The addresses generated by the Assembler
are to be interpreted as absolute locations in memory.
The program is a complete entity; external symbols,
common storage references, and entry points are not
permitted.

Relocatable - The program may be located anywhere in
memory. All operands which refer to memory locations
are adjusted as the program is loaded. Operands, other
than those referring to the first 64 locations, must be re-
locatable expressions. Subprograms may contain external
symbols and entry points, and may refer to common
storage.

Binary output - An absolute or relocatable program is
to be punched on the paper tape.

List output - A program listing is produced either during
pass two or pass three.

Table print - List the symbol table at the end of the first
pass.

Selective assembly - Sections of the program may be
included or excluded at assembly time depending on the
option used.

-----------------
[1] See Chapter 5 for complete details.

1-4

INSTRUCTION FORMAT

A source language statement consists of a label, an operation
code, an operand, and comments. The label is used when needed
as a reference by other statements. The operation code may
be a mnemonic machine operation or an assembly directing
pseudo code. An operand may be an expression consisting of
an alphanumeric symbol, a number, a special character, or
any of these combined by arithmetic operations. (For the
Extended Assembler, an operand may also be a literal.)
Indicators may be appended to the operand to specify certain
functions such as indirect addressing. The comments portion
of the statement is optional.

2.1 STATEMENT CHARACTERISTICS

The fields of the source statement appear in the following
order:

Label
Opcode
Operand
Comments

FIELD DELIMITERS

One or more spaces separate the fields of a statement. An
end-of-statement mark terminates the entire statement. On
paper tape this mark is a return, (CR), and a line feed, (LF). [1]
A single space following the end-of-statement mark from the
previous source statement is the null field indicator of the
label field.

CHARACTER SET

The characters that may appear in a statement are as follows:

A through Z
0 through 9
. (period)
* (asterisk)

---------------------
[1] A circled symbol, e.g. (CR), represents an ASCII code or
Teleprinter key.
2-1

----------------------------------------------------------------------------
| Label Operation Operand Comments |
|----------------------------------------------------------------------------|
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
----------------------------------------------------------------------------

SAMPLE CODING FORM
(Actual Size 11 x 13 1/2)

2-2

+ (plus)
- (minus)
, (comma)
= (equals)
() (parenthesis)
(space)

Any other ASCII characters may appear in the Remarks field
(See Appendix A).

The letters A through Z, the numbers 0 through 9, and the
period may be used in an alphanumeric symbol. In the first
position in the Label field, an asterisk indicates a comment;
in the Operand field, it represents the value of the program
location counter for the current instruction. The plus and
minus are used as operators in arithmetic address expres-
sions. The comma separates several operation codes, or an
expression and an indicator in the Operand field. An equals
sign indicates a literal value. The parentheses are used only
in the COM pseudo instruction.

Spaces separate fields of a statement. They may also be used
to establish the format of the output list. Within a field they
may be used freely when following +, -, ,, or (.

STATEMENT LENGTH

A statement may contain up to 80 characters including blanks,
but excluding the end-of-statement mark. Fields beginning in
characters 73-80 are not processed by the Assembler.

2.2 LABEL FIELD

The Label field identifies the statement and may be used as a
reference point by other statements in the program.

Te field starts in position one of the statement; the first
position following an end-of-statement mark for the preceding
statement. It is terminated by a space. A space in position
one is the null field indicator for the label field; the statement
is unlabeled.

LABEL SYMBOL

A label must be symbolic. It may have one to five characters
consisting of A through Z, 0 through 9, and the period. The

2-3

first character must be alphabetic or a period. A label of
more than five characters could be entered on the source lan-
guage tape, but the Assembler flags this condition as an error
and truncates the label from the right to five characters.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
LDA NO LABEL
.ABCD VALID LABEL
.1234 VALID LABEL
A.123 VALID LABEL
. VALID LABEL
1.AB ILLEGAL LABEL - FIRST CHARACTER NUMERIC
ABC123 ILLEGAL LABEL - TRUNCATED TO ABC12
A*BC ILLEGAL LABEL - ASTERISK NOT ALLOWED IN LABEL
ABC NO LABEL - THE ASSEMBLER ATTEMPTS TO INTERPRET
ABC AS AN OPERATION CODE

Each label must be unique within the program; two or more
statements may not have the same symbolic name. Names
which appear in the Operand field of an EXT or COM pseudo
instruction may not also be used as statement labels in the
same subprogram.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
COM ACOM(20),BC(30)
LB EQU 160 VALID LABEL
EXT XL1,XL2
START LDA LB VALID LABEL
N25 VALID LABEL
XL2 ILLEGAL LABEL - USED IN EXT
BC ILLEGAL LABEL - USED IN COM
N25 ILLEGAL LABEL - PREVIOUSLY DEFINED

2-4

ASTERISK

An asterisk in position one indicates that the entire statement
is a comment. Positions 2 through 80 are available; however,
positions 1 through 68 only are printed as part of the assembly
listing on the 2672A Teleprinter. An asterisk within the Label
field is illegal in any position other than one.

2.3 OPCODE FIELD

The operation code defines an operation to be performed by
the computer or the Assembler. The Opcode field follows the
Label field and is separated from it by at least one space. If
there is no label, the operation code may begin anywhere after
position one. The Opcode field is terminated by a space im-
mediately following an operation code. Operation codes are
organized in the following categories:

Machine operation codes
Memory Reference
Register Reference
Input/Output, Overflow, and Halt
Extended Arithmetic Unit
Pseudo operation codes
Assembler control
Object program linkage
Address and symbol definition
Constant definition
Storage allocation
Arithmetic subroutine calls
Assembly Listing Control (Extended Assembler)

Operation codes are discussed in detail in Chapters 3 and 4.

2.4 OPERAND FIELD

The meaning and format of the Operand field depend on the
type of operation code used in the source statement. The field
follows the Opcode field and is separated from it by at least
one space. It is terminated by a space except when the space
follows , + - ( or, if there are no comments, by an end-of-
statement mark.

2-5

The operand field may contain an expression consisting of one
of the following:

Single symbolic term

Single numeric term

Asterisk

Combination of symbolic terms, numeric terms, and the
asterisk joined by the arithmetic operators + and -.

An expression may be followed by a comma and an
indicator.

Programs being assembled by the Extended Assembler
may also contain a literal value in the Operand field.

SYMBOLIC TERMS

A symbolic term may be one to five characters consisting of
A through Z, 0 through 9, and the period. The first character
must be alphabetic or a period.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
LDA A1234 VALID IF DEFINED
ADA B.1 VALID IF DEFINED
JMP ENTRY VALID IF DEFINED
STA 1ABC ILLEGAL OPERAND - FIRST CHARACTER NUMERIC
STB ABCDEF ILLEGAL OPERAND - MORE THAN FIVE CHARACTERS

A symbol used in the Operand field must be a symbol that is
defined elsewhere in the program in one of the following ways:

As a label in the Label field of a machine operation

As a label in the Label field of a BSS, ASC, DEC, OCT,
DEF, ABS, EQU or REP pseudo operation

As a name in the Operand field of a COM or EXT pseudo
operation

As a label in the Label field of an arithmetic subroutine
pseudo operation.

2-6

The value of a symbol is absolute or relocatable depending on
the assembly option selected by the user. The assembler as-
signs a value to a symbol as it appears in one of the above
fields of a statement. If a program is to be loaded in absolute
form, the values assigned by the assembler remain fixed. If
the program is to be relocated, the actual value of a symbol is
established on loading. A symbol may also be made absolute
through use of the EQU pseudo instruction.

A symbolic term may be preceded by a plus or minus sign. If
preceded by a plus or no sign, the symbol refers to its associ-
ated value. If preceded by a minus sign, the symbol refers to
the two's complement of its associated value. A single nega-
tive symbolic operand may be used only with the ABS pseudo
operation.

NUMERIC TERMS

A numeric term may be decimal or octal. A decimal number
is represented by one to five digits within the range 0 to
32767. An octal number is represented by one to six octal
digits followed by the letter B; (0 to 177777B).

If a numeric term is preceded by a plus or no sign, the binary
equivalent of the number is used in the object code. If pre-
ceded by a minus sign, the two's complement of the binary
equivalent is used. A negative numeric operand may be used
only with the DEX, DEC, OCT, and ABS pseudo operations.

In an absolute program, the maximum value of a numeric
operand depends on the type of machine or psuedo instruction.
In a relocatable program, the value or a numeric operand may
not exceed 77B. Numeric operands are absolute. Their value
is not altered by the assembler or the loader.

ASTERISK

An asterisk in the Operand field refers to the value in the
program location counter (or base page location counter) at the
time the source program statement is encountered. The
asterisk is considered a relocatable term in a relocatable
program.

EXPRESSION OPERATORS

The asterisk, symbols, and numbers may be joined by the
arithmetic operators + and - to form arithmetic address ex-
pressions. The Assembler evaluates an expression and pro-
duces an absolute or relocatable value in the object code.

2-7

Examples:

If P1 and P2 are program relocatable terms; B1 and B2, base
page relocatable; C1 and C2, common relocatable; and A, an
absolute term; then the following are absolute terms:

A-C1+C2 A-P1+P2 C1-C2+A
A+A P1-P2 B1-B2
*-P1 B1-B2-A -C1+C2+A
B1-* -P1+P2 -A-P1+P2

The asterisk is base page relocatable or program relocatable
depending on the location of the instruction.

RELOCATABLE EXPRESSIONS

A relocatable expression is one whose value is changed by the
loader. All relocatable expressions must have a positive
value.

A relocatable expression may contain any odd number of relo-
catable terms, alone, or in combination with absolute terms.
All relocatable terms must be of the same type. Terms must
be paired by sign with the odd term being positive.

A relocatable expression reduces to a single positive relo-
catable term, adjusted by the valued represented by the abso-
lute terms and paired relocatable terms associated with it.

Examples:

If P1, P2 and P3 are program relocatable terms; B1, B2 and
B3, base page relocatable; C1, C2 and C3, common relocatable;
and A, an absolute term, then the following are relocatable
terms:

P1-A C1-A B1+A
P1-P2+P3 C1-C2+C3 C1+A
*+A *-P1+P2 *-A
A+B1 A+C1 -A-P1+P2+P3
B1-B2+B3-A C1-C2+C3-A A+*
*+P1-* P1-P2+* -C1+C2+C3

2-10

LITERALS

Actual literal values may be specified as operands in re-
locatable programs to be assembled by the Extended Assembler.
The Extended Assembler converts the literal to its binary
value, assigns an address to it, and substitutes this address
as the operand. Locations assigned to literals are those
immediately following the last location used by the program.

A literal is specified by using an equal sign and a one-
character identifier defining the type of the literal. The actual
literal value is specified immediately following this identifier;
no spaces may intervene.

The identifiers are:

=D a decimal integer, in the range -32767 to 32767,
including zero. [1]

=F a floating-point number; any positive or negative
real number in the range 10**-38 to 10**38, including
zero. [1]

=B an octal integer, one to six digits, b1b2b3b4b5b6,
where b1 may be 0 or 1, and b2-b7 may be 0 to 7. [1]

=A two ASCII characters. [1]

=L an expression which, when evaluated, will result
in an absolute value. All symbols appearing in the
expression must be previously defined.

If the same literal is used in more than one instruction,
only one value is generated, and all instructions using this
literal refer to the same location.

Literals may be specified only in the following memory
reference instructions and pseudo instructions:

ADA DSB AND MPY \
LDA LDB XOR DIV > may use =D, =B, =A, =L
CPA CPB IOR /

DLD FAD \
FMP FSB > may use =F
FDV /

---------------------
[1] See CONSTANT DEFINITION, Section 4.4.

2-11

Examples:

LDA =D7980 A-Register is loaded with the binary equiv-
alent of 7980 base 10.

IOR =B777 Inclusive "or" is performed with contents of
A-Register and 777 base 8

LDA =ANO A-Register is loaded with binary representa-
tion of ASCII characters NO.

LDB =LZETZ-ZOOM+68 B-Register is loaded with the value resulting
from the absolute expression

FMP =F39.75 Contents of A- and B-Registers multiplied
by floating-point constant 39.75.

INDIRECT ADDRESSING

The HP computers provide an indirect addressing capability
for Memory Reference instructions. The operand portion of
an indirect instruction contains an address of another location
rather than an actual operand. The secondary location may be
the operand or it may be indirect also and give yet another
location, and so forth. The chaining ceases when a location is
encountered that does not contain an indirect address. Indirect
addressing provides a simplified method of address modifi-
cations as wall as allowing access to any location in core.

The Assembler allows specification of indirect addressing by
appending a comma and the letter I to any Memory Reference
operand other than one referring to an external symbol. The
actual operand of the instruction may be given in a DEF pseudo
operation; this pseudo operation may also be used to indicate
further levels of indirect addressing.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
AB LDA SAM,I EACH TIME THE ISZ IS EXECUTED,
AC ADA SAM,I THE EFFECTIVE OPERAND OF AB AND
AD ISZ SAM AC CHANGE ACCORDINGLY.
.
.
.
SAM DEF ROGER

2-12

A relocatable assembly language program, however, may be
designed without concern for the pages in which it will be
stored; indirect addressing is not required in the source lan-
guage. When the program is being loaded, the loader provides
indirect addressing whenever it detects an operand which does
not fall in the current page or the base page. The loader sub-
stitutes a reference to the base page and then stores an indirect
address in this referenced location. References to the same
operand from other pages will be linked through the same loca-
tion in the base page.

BASE PAGE ADDRESSING

The computer provides a capability which allows the Memory
Reference instructions to address either the current page or
the base page. The Assembler or the loader adjusts all instruc-
tions in which the operands refer to the base page; specific nota-
tion defining an operand as a base page reference is not required
in the source program.

CLEAR FLAG INDICATOR

The majority of the input/output instructions can alter the
status of the input/output interrupt flag after execution or
after the particular test is performed. In source language,
this function is selected by appending a comma and a letter C
to the Operand field.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
STC IO7,C CLEAR FLAG IO7 AFTER CONTROL BIT IS SET
OTB IO5,C CLEAR FLAT IO5 AFTER MOVE

2.5 COMMENTS FIELD

The comments field allows the user to transcribe notes on the
program that will be listed with source language coding on the
output produced by the Assembler. The field follows the
Operand field and is separated form it by at least one space.
The end-of-statement mark, (CR)(LF), or the 80th character
in the entire statement terminates the field. If the listing is to
be produced on the 2752A Teleprinter, the total statement
length, excluding the end-of-statement mark, should not ex-

2-13

ceed 52 characters, the width of the source language portion
of the listing. Statements consisting solely of comments may
contain up to 68 characters including the asterisk in the first
position. On the list output, statements consisting entirely
of comments begin in position 5 rather than 21 as with other
source statements.

If there is no operand present, the Comments field should be
omitted in the NAM and END pseudo operations and in the input/
output statements SOC, SOS and HLT instruction. If a comment
is used, the Assembler attempts to interpret it as an operand.

2-14

MACHINE INSTRUCTIONS

The HP Assembler language machine instruction codes take the
form of three-letter mnemonics. Each source statement cor-
responds to a machine operation in the object program pro-
duced by the assembler.

Notation used in representing source language instruction is
as follows:

label Optional statement label

m Memory location -- an expression

I Indirect addressing indicator

sc Select code -- an expression

C Clear interrupt flag indicator

comments Optional comments

[ ] Brackets defining a field or portion of a
field that is optional

{ } Braces indicating that one of the set
may be selected

lit literal

3.1 MEMORY REFERENCE

Memory Reference instructions perform arithmetic, logical
and jump operations on the contents of the locations in core
and the registers. An instruction may directly address the
2048 words of the current and base pages. If required, in-
direct addressing may be utilized to refer to all 32,768 words
of memory. Expressions in the operand field are evaluated
modulo 2**10.

If the program is to be assembled in relocatable form, the
operand field may contain relocatable expressions or absolute
expressions which are less than 100(8) in value. If the program
is to be absolute, the operands may be any expressions con-
sistent with the location of the program. Literals may not be
used in an absolute program. Absolute programs must be
complete entities; they may not refer to external subroutines
or common storage.

3-1

JUMP AND INCREMENT-SKIP

Jump and Increment-Skip instructions may alter the normal
sequence of program execution.

------+-----+---------+--------
label JMP m[,I] comments

Jump to m. Jump indirect inhibits interrupt until the transfer
of control is complete.

------+-----+---------+--------
label JSB m[,I] comments

Jump to subroutine. The address for label_1 is placed into
the location represented by m and control transfers to m+1.
On completion of the subroutine, control may be returned to
the normal sequence by performing a JMP m,I.

------+-----+---------+--------
label ISZ m[,I] comments

Increment, then skip if zero. ISZ adds 1 to the contents of m.
If m then equals zero, the next instruction in memory is by-
passed.

ADD, LOAD, AND STORE

Add, Load, and Store instructions transmit and alter the con-
tents of memory and of the A- and B-Registers. A literal,
indicated by "lit", may be either =D, =B, =A, or =I type.

------+-----+---------+--------
label ADA m[,I] comments
lit

Add the contents of m to A.

------+-----+---------+--------
label ADB m[,I] comments
lit

Add the contents of m to B.

------+-----+---------+--------
label LDA m[,I] comments
lit

Load A from m.

------+-----+---------+--------
label LDB m[,I] comments
lit

Load B from m.

3-2

------+-----+---------+--------
label STA m[,I] comments

Store contents of A in m.

------+-----+---------+--------
label STB m[,I] comments

Store contents of B in m.

In each instruction, the contents of the sending location is un-
changed after execution.

LOGICAL OPERATIONS

The Logical operations allow bit manipulation and the com-
parison of two computer words.

------+-----+---------+--------
label AND m[,I] comments

The logical product of the contents of m and the contents of A
are placed in A.

------+-----+---------+--------
label XOR m[,I] comments

The modulo-two sum (exclusive "or") of the bits in m and the
bits in A is placed in A.

------+-----+---------+--------
label IOR m[,I] comments

The logical sum (inclusive "or") of the bits in m and the bits
in A is placed in A.

------+-----+---------+--------
label CPA m[,I] comments

Compare the contents of m with the contents of A. If they
differ, skip the next instruction; otherwise, continue.

------+-----+---------+--------
label CPB m[,I] comments

Compare the contents of m with the contents of B. If they
differ, skip the next instruction; otherwise, continue.
3-3

3.2 REGISTER REFERENCE

The Register Reference instructions include a Shift-Rotate
group, an Alter-Skip group, and NOP (no-operation). With
the exception of NOP, they have the capability of causing
several actions to take place during one memory cycle. Mul-
tiple operations within a statement are separated by a comma.

SHIFT-ROTATE GROUP

This group contains 19 basic instructions that can be combined
to produce more then 500 different single cycle operations.

CLE Clear E to zero

ALS Shift A left one bit, zero to least significant bit.
Sign unaltered

BLS Shift B left one bit, zero to least significant bit.
Sign unaltered

ARS Shift A right one bit, extend sign; sign unaltered.

BRS Shift B right one bit, extend sign; sign unaltered.

RAL Rotate A left one bit

RBL Rotate B left one bit

RAR Rotate A right one bit

RBR Rotate B right one bit

ALR Shift A left one bit, clear sign, zero to least
significant bit

BLR Shift B left one bit, clear sign, zero to least
significant bit

ERA Rotate E and A right one bit

ERB Rotate E and B right one bit

ELA Rotate E and A left one bit

ELB Rotate E and B left one bit

ALF Rotate A left four bits

BLF Rotate B left four bits

SLA Skip next instruction if least significant bit in A
is zero

SLB Skip next instruction if least significant bit in B
is zero
3-4

These instructions may be combined as follows:

------+-----------------------+-------
ALS ALS
ARS ARS
RAL RAL
label RAR , CLE , SLA , RAR comments
ALF ALF
ERA ERA
ELA ELA

------+-----------------------+-------
BLS BLS
BRS BRS
RBL RBL
label RBR , CLE , SLB , RBR comments
BLF BLF
ERB ERB
ELB ELB

CLE, SLA or SLB appearing alone or in any valid combination
with each other are assumed to be a Shift-Rotate machine
instruction.

The Shift-Rotate instructions must be given in the order
shown. At least one and up to four are included in cone state-
ment. Instructions referring to the A-register may not be
combined in the same statement with those referring to the
B-register.

NO-OPERATION INSTRUCTION

When a no-operation is encountered in a program, no action
takes place; the computer goes on to the next instruction. A
full memory cycle is used in executing a no-operation instruc-
tion.

------+-----+---------+--------
label NOP comments

A subroutine to be entered by a JSB instruction should have a
3-5

NOP as the first statement. The return address can be stored
in the location occupied by the NOP during execution of the
program. A NOP statement causes the Assembler to generate
a word of zeros.

ALTER-SKIP GROUP

The Alter-Skip group contains 19 basic instructions that can
be combined to produce more than 700 different single cycle
operations.

CLA Clear the A-Register

CLB Clear the B-Register

CMA Complement the A-Register

CMB Complement the B-Register

CCA Clear, then complement the A-Register (set to
ones)

CCB Clear, then complement the B-Register (set to
ones)

CLE Clear the E-Register

CME Complement the E-Register

CCE Clear, then complement the E-Register

SEZ Skip next instruction if E is zero

SSA Skip if sign of A is positive (0)

SSB Skip if sign of B is positive (0)

INA Increment A by one.

INB Increment B by one.

SZA Skip if contents of A equals zero

SZB Skip if contents of B equals zero

SLA Skip if least significant bit of A is zero

SLB Skip if least significant bit of B is zero

RSS Reverse the sense of the skip instructions. If
no skip instructions precede in the statement,
skip the next instruction.
3-6

These instructions may be combined as follows:

------+-----------------------------------------------+-------
CLA CLE
label CMA , SEZ , CME , SSA , SLA , INA , SZA , RSS comments
CCA CCE

------+-----------------------------------------------+-------
CLB CLE
label CMB , SEZ , CME , SSB , SLB , INB , SZB , RSS comments
CCB CCE

The Alter-Skip instructions must be given in the order shown.
At least one and up to eight are included in one statement. In-
structions referring to the A-register may not be combined in
the same statement with those referring to the B-register.
When two or more skip functions are combined in a single
operation, a skip occurs if any one of the conditions exists.
If a word with RSS also includes both SSA and SLA (or SSB and
SLB) a skip occurs only when sign and least significant bit are
both set (1).

3.3 INPUT/OUTPUT, OVERFLOW, AND HALT

The input/output instructions allow the user to transfer data
to and from an external device via a buffer, to enable or dis-
able external interrupt, or to check the status of I/O devices
and operations. A subset of these instructions permits check-
ing for an arithmetic overflow condition.

Input/Output instructions require the designation of a select
code, sc, which indicates one of 64 input/output channels or
functions. Each channel consists of a connect/disconnect con-
trol bit, a flag bit, and a buffer of up to 16 bits. The setting
of the control bits indicates that a device associated with the
channel is operable. The flag bit is set automatically when
transmission between the device and the buffer is completed.
Instructions are also available to test or clear the flag bit for
the particular channel. If the interrupt system is enabled,
setting of the flag causes program interrupt to occur; control
transfers to the interrupt location related to the channel.

3-7

Expressions used to represent select codes (channel numbers)
must have a value of less than 2**6. The value specifies the de-
vice or operation referenced. Instructions which transfer data
between the A or B register and a buffer, access the Switch
register when sc = 1. The character C appended to such an
instruction clears the overflow bit after the transfer from the
Switch register is complete.

INPUT/OUTPUT

Prior to any input/output data transmission, the control bit is
set. The instruction which enables the device may also trans-
fer data between the device and the buffer.

------+-----+---------+--------
label STC sc [,C] comments

Set I/O control bit for channel specified by sc. STC transfers
or enables transfer of an element of data from an input device
to the buffer or to an output device from the buffer. The exact
function of STC depends on the device; for the 2752A Teleprinter,
an STC enables transfer of a series of bits. If sc = 1,
this statement is treated as NOP. The C option clears the flag
bit for the channel.

------+-----+---------+--------
label CLC sc [,C] comments

Clear I/O control bit for channel specified by sc. When the
control bit is cleared, interrupt on the channel is disabled,
although the flag may still be set by the device. If sc = 0,
control bits for all channels are cleared to zero; all devices
are disconnected. If sc - 1 this statement is treated as NOP.

------+-----+---------+--------
label LIA sc [,C] comments

Load into A the contents of the I/O buffer indicated by sc.

------+-----+---------+--------
label LIB sc [,C] comments

Load into B the contents of the I/O buffer indicated by sc.

------+-----+---------+--------
label LIA sc [,C] comments

Merge (inclusive "or") the contents of the I/O buffer indicated
by sc into A.
3-8

------+-----+---------+--------
label MIA sc [,C] comments

Merge (inclusive "or") the contents of the I/O buffer indicated
by sc into B.

------+-----+---------+--------
label OTA sc [,C] comments

Output the contents of A to the I/O buffer indicated by sc.

------+-----+---------+--------
label OTB sc [,C] comments

Output the contents of B to the I/O buffer indicated by sc.

------+-----+---------+--------
label STF sc comments

Sets the flag bit of the channel indicated by sc. If sc = 0, STF
enables the interrupt system. A sc code of 1 causes the over-
flow bit to be set.

------+-----+---------+--------
label CLF sc comments

Clear the flag bit to zero for the channel indicated by sc. If
sc = 0, CLF disables the interrupt system, If sc = 1, the
overflow bit is cleared to zero.

------+-----+---------+--------
label SFC sc comments

Skip the next instruction if the flag bit for channel sc is clear.
If sc = 1, the overflow is tested.

------+-----+---------+--------
label SFS sc comments

Skip the next instruction if the flag bit for channel sc is set.
If sc = 1, the overflow is tested.

OVERFLOW

In addition to the use of a select code of 1, the overflow bit
may be accessed by the following instructions:
3-9

------+-----+---------+--------
label CLO comments

Clear the overflow bit.

------+-----+---------+--------
label STO comments

Set the overflow bit.

------+-----+---------+--------
label SOC [C] comments

Skip the next instruction if the overflow bit is clear. The C
option clears the bit after the test is performed.

------+-----+---------+--------
label SOS [C] comments

Skip the next instruction if the overflow bit is set. The C
option clears the bit after the test is performed.

The C option is identified by the sequence 'space C space' follow-
ing either 'SOC' or 'SOS'. Anything else is treated as a comment.

HALT

------+-----+---------+--------
label HLT [sc[,C]] comments
[C]

Halt the computer. The machine instruction word is displayed
in the T-Register. If the C option is used, the flag bit associ-
ated with channel sc is cleared.

If neither the select code nor the C option is used, the com-
ments portion must be omitted.

3-10

3.4 EXTENDED ARITHMETIC INSTRUCTIONS

Ten instructions are used with the extended arithmetic version of the
Assembler or Extended Assembler to increase the computer's overall
efficiency. They provide for integer multiply and divide and for loading
and storing double-length words to and from the accumulators.

------+-----+---------+--------
label MPY m[,I] comments
lit

The MPY instruction multiplies the contents of the A-Register
by the contents of M. The product is stored in registers B
and A. B contains the sign of the product and the 15 most
significant bits; A contains the least significant bits.

------+-----+---------+--------
label DIV m[,I] comments
lit

The DIV instruction divides the contents of registers B and A
by the contents of m. The quotient is stored in A and the
remainder in B. Initially B contains the sign and the 15 most
significant bits of the dividend; A contains the least significant
bits.

------+-----+---------+--------
label DLD m[,I] comments
lit

The DLD instruction loads the contents of locations m and
m + 1 into registers A and B, respectively.

------+-----+---------+--------
label DST m[,I] comments

The DST instruction stores the contents of registers A and
B in locations m and m + 1, respectively.

MPY, DIV, DLD, DST results in two machine words: a word
for the instruction code and one for the operand.

3-11

The above four instructions are available without the extended arithmetic
instructions as software subroutines. [1] However, by using the extended
arithmetic group, they require less core storage and can be executed in
less time.

The following shift-rotate instructions provide the capability to shift or
rotate the B- and A- Registers n number of bit positions, where
1 <= n <= 16.

------+-----+---------+--------
label ASR n comments

The ASR instruction arithmetically shifts the B- and A-
Registers right n bits. The sign bit (bit 15 of B) is extended.

------+-----+---------+--------
label ASL n comments

The ASL instruction arithmetically shifts the B- and A-
Registers left n bits. Zeroes are placed in the least significant
bits. The sign bit (bit 15 of B) is unaltered. The overflow bit
is set if bit 14 differs from bit 15 before each shift, otherwise,
exit with Overflow bit cleared.

------+-----+---------+--------
label RRR n comments

The RRR instruction rotates the B- and A-Registers right n bits.

------+-----+---------+--------
label RRL n comments

The RRL instruction rotates the B- and A-Registers left n bits.

------+-----+---------+--------
label LSR n comments

The LSR instruction logically shifts the B- and A-Registers
right n bits. Zeroes are placed in the most significant bits.

------+-----+---------+--------
label LSL n comments

The LSL instruction logically shifts the B- and A-Registers
left n bits. Place zeroes in the least significant bits.

---------------------
[1] See ARITHMETIC SUBROUTINE CALLS, Section 4.7.

3-12

3.5 FLOATING-POINT INSTRUCTIONS

Floating-point instructions provide a means of performing calcu-
lations on floating-point values. Computers with the hardware
floating-point option should use assemblers and libraries with
floating-point capabilities. The floating-point assembler gener-
ates calls to the appropriate hardware function instead of the
library subroutines. If the computer does not have the hardware
floating-point option, then non-floating-point assemblers and
libraries should be used.

------+-----+---------+--------
label FAD m[,I] comments
lit

FAD performs an addition between a floating-point number stored
in the A- and B-Registers and a floating-point number stored in
memory locations m and m + 1. The result is returned in the
A- and B-Registers.

------+-----+---------+--------
label FSB m[,I] comments
lit

The FSB instruction subtracts a floating-point value in memory
locations m and m + 1 from a floating-point value in the A- and
B-Registers. The result is returned in the A- and B-Registers.

------+-----+---------+--------
label FMP m[,I] comments
lit

The FMP instruction multiplies a floating-point value in memory
locations m and m + 1 with a floating-point value in the A- and
B-Registers. The result is returned in the A- and B-Registers.

------+-----+---------+--------
label FDV m[,I] comments
lit

The FDV instruction divides a floating-point value in memory
locations m and m + 1 into a floating-point value in the A- and
B-Registers. The result is returned in the A- and B-Registers.

3-13

------+-----+---------+--------
label FIX comments

The FIX instruction converts a floating-point number contained
in the A- and B-Registers to a fixed point number. The result is
returned in the A-Register. The contents of the B-Register are
meaningless.

------+-----+---------+--------
label FLT comments

The FLT instruction converts a fixed-point number contained in the
A-Registers to a floating-point value. The result is returned in
the A- and B-Registers.

3-14

PSEUDO INSTRUCTIONS

The pseudo instructions control the Assembler, establish pro-
gram relocatability, and define program linkage as well as
specify various types of constants, blocks of memory, and
labels used in the program. With the Extended Assembler,
pseudo instructions also control listing output.

4.1 ASSEMBLER CONTROL

The Assembler control pseudo instructions establish and alter
the contents of the base page and program location counters,
and terminate assembly processing. Labels may be used but
they are ignored by the assembler. NAM records produced
by the Assemblers are accepted by the DOS, DOS-M, and BCS
Loaders.

------+-----+---------+--------
NAM [name] comments

NAM defines the name of a relocatable program. A relocatable
program must begin with a NAM statement.[1] A relocat-
able program is assembled assuming a starting location of
zero (i.e., zero relative). The name may be a symbol of one
to five alphanumeric characters the first of which must be
alphabetic or a period. The program name is printed on the
list output. The name is optional and if omitted, the comments
must be omitted also.

------+-----+---------+--------
ORG m comments

The ORG statement defines the origin of an absolute program,
or the origin of subsequent sections of absolute or relocatable
programs.

An absolute program must begin with an ORG statement. [1]
The operand m, must be a decimal or octal integer specifying
the initial setting of the program location counter.

--------------------
[1] The Control Statement, the HED instruction, and comments
may appear prior to the NAM or ORG statements. If the
Control Statement (ASMB,...) does not appear on tape pre-
ceding the program it must be entered from the Teleprinter.

4-1

ORG statements may be used elsewhere in the program to
define starting addresses for portions of the object code. For
absolute programs the Operand field, m, may be any expres-
sion. For relocatable programs, m, must be a program
relocatable expression; it may not be base page or common
relocatable or absolute. An expression is evaluated modulo
2**15. Symbols must be previously defined. All instructions
following an ORG are assembled at consecutive addresses
starting with the value of the operand.

------+-----+---------+--------
ORR comments

ORR resets the program location counter to the value existing
when an ORG or ORB instruction was encountered.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM RSET SET PLC TO VALUE OF ZERO, ASSIGN
FIRST ADA RSET AS NAME OF PROGRAM.
.
.
.
ADA CTRL ASSUME PLC AT FIRST+2280
ORG FIRST+2926 SAVE PLC VALUE OF FIRST+2280
. AND SET PLC TO FIRST+2926
JMP EVEN+1 ASSUME PLC AT FIRST+3004
ORR RESET PLC TO FIRST+2280

More than one ORG or ORB statement may occur before an
ORR is used. If so, when the ORR is encountered, the pro-
gram location counter is reset to the value it contained when
the first ORG or ORB of the string occurred.

4-2

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM RSET SET PLC TO ZERO
FIRST ADA
.
.
.
LDA WYZ ASSUME PLC AT FIRST+2250
ORG FIRST+2500 SET PLC TO FIRST+2500
.
.
.
LDB ERA ASSUME PLC AT FIRST+2750
ORG FIRST+2900 SET PLC TO FIRST+2900
.
.
.
CLE ASSUME PLC AT FIRST+2920
ORR RESET PLC TO FIRST+2250

If a second ORR appears before an intervening ORG or ORB,
the second ORR is ignored.

ORR cannot be used to reset the location counter for locations
in base page that are governed by the ORB statement.

------+-----+---------+--------
ORB comments

ORB defines the portion of a relocatable program that must be
assigned to the base page by the Assembler. The Label field
(if given) is ignored, and the statement requires no operand. All
statements that follow the ORB statement are assigned con-
tiguous locations in the base page. Assignment to the base
page terminates when the Assembler detects an ORG, ORR, or
END statement.

When more than one ORB is used in a program, each ORB
causes the Assembler to resume assigning base page locations
at the address following the last assigned base page location.

An ORB statement in an absolute program has no significance
and is flagged as an error.

4-3

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM PROG ASSIGN ZERO AS RELATIVE STARTING
. LOCATION FOR PROGRAM PROG
.
.
ORB ASSIGN ALL FOLLOWING STATEMENTS
TO BASE PAGE
IAREA BSS 100
.
.
.
ORR CONTINUE MAIN PROGRAM
.
.
ORB RESUME ASSIGNMENT AT NEXT
. AVAILABLE LOCATION IS BASE PAGE
.
.
ORR CONTINUE MAIN PROGRAM

The IFN and IFZ pseudo instructions cause the inclusion of
instructions in a program provided that either an "N" or "Z",
respectively, is specified as a parameter for the ASMB control
statement.[1] The IFN or IFZ instructions precedes the set of
statements that are to be included. The pseudo instruction XIF
serves as a terminator. If XIF is omitted, END act as a
terminator to both the set of statements and the assembly. IFN
and IFZ may be used only when the source program is trans-
lated by the Extended Assembler which is provided for 8K or
larger machines.

1 5 10 15 20 25 30 35 40
----------------------------------------
IFN comments
.
.
.
XIF

All source language statements appearing between the IFN and
the XIF pseudo instructions are included in the program if the
character "N" is specified on the ASMB control statement.

All source language statements appearing between the IFZ and
the XIF pseudo instruction are included in the program if the
character "Z" is specified on the ASMB control statement.

1 5 10 15 20 25 30 35 40
----------------------------------------
IFZ comments
.
.
.
XIF

----------------------
[1] See CONTROL STATEMENT, Section 5.1

4-4

When the particular letter is not included on the control state-
ment, the related set of statements appears on the Assembler
output listing but is not assembled.

Any number of IFN-XIF and IFZ-XIF sets may appear in a
program, however, they may not overlap. An IFZ or IFN
intervening between and IFZ or IFN and the XIF terminator
results in a diagnostic being issued during compilation; the
second pseudo instruction is ignored.

Both IFN-XIF and IFZ-XIF pseudo instructions may be used
in the program; however, only one type will be selected in a single
assembly. Therefore, if both characters "N" and "Z" appear
in the control statement, the character which is listed last will
determine the set of coding that is to be included in the program.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM TRAVL
.
.
.
IFZ
LDA CAR
CMA,SZA
JMP NO.GO
LDA MILES
DIV SPEED
STA GAS
XIF
.
.
.
IFN
LDA PLANE
CMA,SZA
JMP NO.GO
LDA TIME
CPA COST
XIF
NO.GO HLT 77
.
.
.
END

Program TRAVL will perform computations involving either
or neither CAR or PLANE considerations depending on the pres-
ence or absence of Z or N parameters in the Control Statement.

4-5

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM WAGE
.
.
.
JSB HOUR
MPY TIME1
IFZ
JMP OVTIM
MPY TIME2
.
.
.
TIME1 DEC 40
TIME2 BSS 1
END

Program WAGES computes a weekly wage value. Overtime
consideration will be included in the program if "Z" is included
in the parameters of the Control Statement.

The REP pseudo instruction, available in the Extended Assem
bler only, causes the repetition of the statement immediately
following it a specified number of times.

------+-----+---------+--------
label REP n comments

The statement following the REP in the source program is
repeated n times. The n may be any absolute expression.
Comment lines (indicated by an asterisk in character position 1)
are not repeated by REP. If a comment follows a REP instruc-
tion, the comment is ignored and the instruction following the
comment is repeated.

A label specified in the REP pseudo instruction is assigned to
the first repetition of the statement. A label cannot be part of
the instruction to be repeated; it would result in a doubly defined
symbol error.

4-6

Example:

CLA
TRIPL REP 3
ADA DATA

The above source code would generate the following:

CLA
TRIPL ADA DATA
ADA DATA
ADA DATA

Example:

FILL REP 100B
NOP

The example above loads 100(8) memory locations with the NOP
instruction. The first location is labeled FILL.

Example:

REP 2
MPY DATA

The above source code would generate the following:

MPY DATA
MPY DATA

------+-----+---------+--------
END [m] comments

This statement terminates the program; it marks the physical
end of the source language statements. The Operand field, m,
may contain a name appearing as a statement label in the cur-
rent program or it may be blank. If a name is entered, it
identifies the location to which the loader transfers control after
a relocatable program is loaded. A NOP should be stored at
that location; the loader transfers control via a JSB.

4-7

If the Operand field is blank, the Comments field must be blank
also, otherwise, the Assembler attempts to interpret the first
five characters of the comments as the transfer address
symbol.

The label field of the END statement is ignored.

4.2 OBJECT PROGRAM LINKAGE

Linking pseudo instructions provide a means for communica-
tion between a main program and its subroutines or among
several subprograms that are to be run as a single program.
These instructions may be used only in a relocatable program.

The Label field of this class is ignored in all cases. The
Operand field is usually divided into many subfields, separated
by commas. The first space not preceded by a comma or a
left parenthesis terminates the entire field.

------+-----+------------------------------------+--------
COM name[(size1)][,name2[(size2)],...] comments

COM reserves a block of storage locations that may be used
in common by several subprograms. Each name identifies a
segment of the block for the subprogram in which the COM
statement appears. The sizes are the number of words allotted
to the related segments. The size is specified as an octal or
decimal integer. If the size is omitted, it is assumed to be
one.

Any number of COM statements may appear in a subprogram.
Storage locations are assigned contiguously; the length of the
block is equal to the sum of the lengths of all segments named
in all COM statements in the subprogram.

To refer to the common block, other subprograms must also
include a COM statement. The segment names and sizes may
be the same or they may differ. Regardless of the names and
sizes specified in the separate subprograms, these is only one
common block for the combined set. It has the same relative
origin; the content of the nth word of common storage is the
same for all subprograms.

4-8

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
PROG1 COM ADDR1(5),ADDR2(10),ADDR3(10)
.
.
LDA ADDR2+1 PICK UP SECOND WORD OF SEGMENT
. ADDR2+1
.
END
.
.
PROG2 COM AAA(2),AAB(2),AAC,AAD(20)
.
.
LDA AAD+1 PICK UP SECOND WORD OF SEGMENT
AAD+1

Organization of common block:

PROG1 PROG2 Common
name name Block
----- ----- ------
ADDR1 AAA (location 1)
(location 2)
AAB (location 3)
(location 4)
AAC (location 5)
ADDR2 AAD (location 6)
(location 7)
(location 8)
(location 9)
(location 10)
(location 11)
(location 12)
(location 13)
(location 14)
(location 15)
ADDR3 (location 16)
(location 17)
(location 18)
(location 19)
(location 20)
(location 21)
(location 22)
(location 23)
(location 24)
(location 25)

4-9

The LDA instructions in the two subprograms each refer to
the same location in common storage, location 7.

The segment names that appear in the COM statements can be
used in the Operand fields of DEF, ABS, EQU, or any Memory
Reference statement; they may not be used as labels elsewhere
in the program.

The loader establishes the origin of the common block; the
origin cannot be set by the ORG or ORB pseudo instruction.
All references to the common area are relocatable.

Two or more subprograms may declare common blocks which
differ is size. The subprogram that defines the largest block
must be the first submitted for loading.

------+-----+------------------------+--------
ENT name1 [, name2 , ... ] comments

ENT defines entry points to the program or subprogram. Each
name is a symbol that is assigned as a label for some machine
operation in the program. Entry points allow another sub-
program to refer to this subprogram. All entry points must be
defined in the program.

Symbols appearing in an ENT statement may not also appear
in EXT or COM statements in the same subprogram.

------+-----+-----------------------+--------
EXT name1 [, name2 , ...] comments

This instructions designates labels from other subprograms which
are referenced in this subprogram. The symbols must be defined
as entry points by the other subprograms.

The symbols defined in the EXT statement may appear in Mem-
ory Reference statements, the EQU or DEF pseudo instructions.
An external symbol must appear alone; it may not be in a mul-
tiple term expression or be specified as indirect. References
to external locations are processed by the BCS loader as indirect
addresses linked through the base page.

4-10

Symbols appearing in EXT statements may not also appear in
ENT or COM statements in the same subprogram. The label
field is ignored.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
PROGA NOP
LDA SAMD SAMD AND SAND ARE REFERENCED IN
. PROGA, BUT ARE ACTUALLY
. LOCATIONS IN PROGB
.
JMP SAND
EXT SAMD,SAND
ENT PROGA
END

PROGB NOP
.
.
SAMD OCT 767
SAND STA SAMD
.
.
ENT SAMD,SAND
.
.
JSB PROGA
.
.
EXT PROGA
.
.
END

4.3 ADDRESS AND SYMBOL DEFINITION

The pseudo operations in this group assign a value or a word
location to a symbol which is used as an operand elsewhere in
the program.

4-11

------+-----+---------+--------
label DEF m,[I] comments

The address definition statement generates one word of mom-
ory as a 15-bit address which may be used as the object of an
indirect address found elsewhere in the source program. The
symbol appearing in the label is that which is referenced; it
appears in the Operand field of a Memory Reference instruc-
tion.

The operand field of the DEF statement may be any positive ex-
pression in an absolute program; in a relocatable program it
may be a relocatable expression or an absolute expression with
a value of less than 100(8). Symbols that do appear in the Oper-
and field, may appear as operands of EXT or COM statements,
in the same subprogram and as entry points in other sub-
programs.

The expression in the Operand field may itself be indirect and
make reference to another DEF statement elsewhere in the
source program.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM PROGN ZERO-RELATIVE START OF PROGRAM
EXT SINE,SQRT
COM SCMA(20),SCMB(50)
.
.
JSB SINE EXECUTE SINE ROUTINE
.
.
LDA XCMA,I PICK UP COMMON WORD INDIRECTLY
.
.
XCMA DEF SCMA SCMA IS A 15-BIT ADDRESS
.
.
JSB XSQ,I GET SQUARE ROOT USING TWO-LEVEL
XSQ DEF XSQR,I INDIRECT ADDRESSING
.
.
XSQR DEF SQRT SQRT IS A 15-BIT ADDRESS
END PROGN

4-12

The DEF statement provides the necessary flexibility to
perform address arithmetic in programs which are to be
assembled in relocatable form. Relocatable programs should
not modify the operand of a memory reference instruction.

In the example below, if TBL and LDTBL are in different
pages, the BCS Loader processes TBL as an indirect address
linked through the base page. The ISZ erroneously increments
the loader provided reference to the base page rather than the
value of TBL.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
LDTBL LDA TBL
.
.
.
ISZ LDTBL
.
.
.
.
TBL BSS 100

Assuming the loader might assign absolute locations compara-
ble to the following octal values:

Page Loc Opcode Reference
---- --- ------ ---------
(0) (700) DEF 4000

(1) (200) LDA (0) 700(I)

(1) (300) ISZ (1) 200

(2) (0) (TBL)

4-13

It can be seen that the ISZ instruction would increment the
quantity 700 rather than the address of the table (4000).

The following assures correct address modification during
program execution.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
ITBL DEF TBL
LDTBL LDA ITBL,I
.
.
.
ISZ ITBL
.
.
.
TBL BSS 100

This sequence might be stored by the loader as:

Page Loc Opcode Reference
---- --- ------ ---------
(1) (200) DEF 4000
(1) (201) LDA 200(I)
(2) (300) ISZ (1) 200
(2) (0) (TBL)

4-14

The value of 4000 is incremented; each execution of LDA will
access successive locations in the table.

------+-----+---------+--------
label ABS m comments

ABS defines a 16-bit absolute value to be stored at the location
represented by the label. The Operand field, m, may be any
absolute expression; a single symbol must be defined as abso-
lute elsewhere in the program.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
AB EQU 35 ASSIGNS THE VALUE OF 35
TO THE SYMBOL AB

M35 ABS -AB M35 CONTAINS -35
P35 ABS AB P35 CONTAINS 35
P70 ABS AB+AB P70 CONTAINS 70
P30 ABS AB-5 P30 CONTAINS 30

------+-----+---------+--------
label EQU m comments

The EQU pseudo operation assigns to a symbol a value other
than the one normally assigned by the program location coun-
ter. The symbol in the Label field is assigned the value
represented by the Operand field. The Operand field may
contain any expression. The value of the operand may be
common, base page or program relocatable as well as abso-
lute, but it may not be negative. Symbols appearing in the
operand must be previously defined in the source program.

The EQU instruction may be used to symbolically equate two
locations in memory; or it may be used to give a value to a
symbol. The EQU statement does not result in a machine
instruction.

4-15

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM FAM
.
.
.
J3 DEF
.
.
.
LDA J3 THE SYMBOLS JFOUR AND J3+1 BOTH
ADA ONE IDENTIFY THE SAME LOCATION. THE
STA J3+1 AND OPERATION IS PERFORMED ON
JFOUR EQU J3+1 THIS LOCATION
.
.
.
MWH AND JFOUR
.
.
.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
NAM STQTB
.
.
.
COM TABLA(10) DEFINES A 10 WORD TABLE, TABLA
.
.
.
TABLB EQU TABLA+5 NAMES WORDS 6 THROUGH 10 OF
. TABLA AS TABLB
.
.
LDA TABLB+1 LOADS CONTENTS OF 7TH WORD
. COMMON INTO A. THE STATEMENT LDA
. TABLA+6 WOULD PERFORM THE SAME
. OPERATION
.
NAM REG
.
.
.
A EQU 0 DEFINES SYMBOL A AS 0 (LOCATION
B EQU 1 OF A-REGISTER), AND SYMBOL B AS
. 1 (LOCATION OF B-REGISTER).
.
LDA B LOADS THE CONTENTS OF B-REGISTER
INTO A-REGISTER.

4-16

4.4 CONSTANT DEFINITION

The pseudo instructions in this class enter a string of one or
more constant values into consecutive words of the object pro-
tram. The statements may be named by labels so that other
program statements can refer to the fields generated by them.

------+-----+-------------------+--------
label ASC n,<2n characters> comments

ASC generates a string of 2n alphanumeric characters in
ASCII code into n consecutive words.[1] One character is right
justified in each eight bits; the most significant bit is zero.
n may be any expression resulting in an unsigned decimal
value in the range 1 through 28. Symbols used in an expres-
sion must be previously defined. Anything in the Operand field
following 2n characters is treated as comments. If less than 2n
characters are detected before the end-of-statement mark,
the remaining characters are assumed to be spaces, and are
stored as such. The label represents the address of the first
two characters.

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
TTYP ASC 3,ABCDE

causes the following:

ALPHABETIC

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
|///| A |///| B |
---------------------------------------------------------------
|///| C |///| D |
---------------------------------------------------------------
|///| E |///| sp |
---------------------------------------------------------------

EQUIVALENT IN OCTAL NOTATION

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
|///| 1 0 1 |///| 1 0 2 |
---------------------------------------------------------------
|///| 1 0 3 |///| 1 0 4 |
---------------------------------------------------------------
|///| 1 0 5 |///| 0 4 0 |
---------------------------------------------------------------

--------------------
[1] To enter the code for the ASCII symbols which perform some
action, e.g., (CR) and (LF), the OCT pseudo instruction
must be used.

4-17

------+-----+----------------+--------
label DEC d1 [, d2, ...] comments

DEC records a string of decimal constants into consecutive
words. The constants may be either integer or real (floating
point), and positive or negative. If no sign is specified, posi-
tive is assumed. The decimal number is converted to its
binary equivalent by the Assembler. The label, if given,
serves as the address of the first word occupied by the
constant.

A decimal integer must be in the range of 0 to 2**15-1; it may
assume positive, negative, or zero values. It is converted
into one binary word and appears as follows:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| s | number |
---------------------------------------------------------------
/
/
sign

Example:

1 5 10 15 20 25 30 35 40
----------------------------------------
INT DEC 50,+328,-300

causes the following (octal representation)

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 0 | 0 | 0 | 0 | 6 | 2 |
---------------------------------------------------------------
| 0 | 0 | 0 | 5 | 1 | 0 |
---------------------------------------------------------------
| 1 | 7 | 7 | 3 | 2 | 4 |
---------------------------------------------------------------

A floating point number has two components, a fraction and an
exponent. The fraction is a signed or unsigned number which
may be written with or without a decimal point. The exponent is
indicated by the letter E and follows a signed or unsigned decimal
integer. The floating-point number may have any of the following
formats:

+-n.n +-n. +-n.nE+-e +-.nE+-e +-nE+-e

4-18

The number is converted to binary, normalized (leading bits
differ), and stored in two computer words. If either the frac-
tion or the exponent is negative, that part is stored in two's
complement form.

Word 1:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| s | fraction (most significant bits) |
---.-----------------------------------------------------------
\ \
\ binary point 4-20
\
sign of fraction 4-22

Word 2:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| fraction | exponent | s |
---------------------------------------------------------------
/
/
sign of exponent

The floating-point number is made up of a 7-bit exponent with
sign and a 23-bit fraction with sign. The number must be in
the approximate range of 10**-38 and zero.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
DEC .45E1
DEC 45.00E-1
DEC 4500E-3
DEC 4.5

are all equivalent to

.45 * 10**1

and are stored in normalized form as:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 0 | 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 |
---------------------------------------------------------------

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 0 0 0 0 0 0 0 0 | 0 0 0 0 0 1 1 | 0 |
---------------------------------------------------------------

4-19

1 5 10 15 20 25 30 35 40
----------------------------------------
DEC -.695,400E-4

are stored as:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 1 | 0 1 0 0 1 1 1 0 0 0 0 1 0 1 0 |
---------------------------------------------------------------

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 0 0 1 1 1 0 1 1 | 0 0 0 0 0 0 0 | 0 |
---------------------------------------------------------------

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 0 | 1 0 1 0 0 0 1 1 1 1 0 1 0 1 1 |
---------------------------------------------------------------

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| 1 0 0 0 0 1 0 1 | 1 1 1 1 1 0 0 | 1 |
---------------------------------------------------------------

------+-----+----------------+--------
label DEX d1 [, d2, ...] comments

DEX, for the Extended Assembler, records a string of
extended precision decimal constants into consecutive words
within a program. Each such extended precision constant
occupies three words as shown below:

Word 1:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
|Sm | Mantissa ----------------------------------> |
---.-----------------------------------------------------------

Word 2:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| ------------------------------------------------> |
---------------------------------------------------------------

Word 3:

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
---------------------------------------------------------------
| --------------------> | exponent |Se |
---------------------------------------------------------------

4-20

Legend:

Sm = Sign of the mantissa (fraction)

Se = Sign of the Exponent

NOTE: A value is entered only if normalizing of the
Mantissa is needed.

An extended precision floating-point number is made up
of a 39-bit Mantissa (fraction) and sign and a 70bit ex-
ponent and sign. The exponent and sign will be zero if
the Mantissa does not have to be normalized.

This is the only form used for DEX. All values, whether
they be floating-point, integer, fraction, or integer and
fraction, will be stored in three words as just described.
This storage format is basically an extension of that used
for DEC, as previously described.

Examples:

DEX 12,-.45

are stored as:

WORD 1 WORD 2 WORD 3
------------------ ------------------ ------------------
| 0110000000000000 | | 0000000000000000 | | 0000000000001000 |
------------------ ------------------ ------------------

WORD 4 WORD 5 WORD 6
------------------ ------------------ ------------------
| 1000110011001100 | | 1100110011001100 | | 1001101111111111 |
------------------ ------------------ ------------------

4-21

------+-----+----------------+--------
label OCT o1 [, o2, ...] comments

OCT stores one or more octal constants in consecutive words
of the object program. Each constant consists of one to six
octal digits (0 to 177777). If no sign is given, the sign is
assumed to be positive. If the sign is negative, the two's com-
plement of the binary equivalent is stored. The constants are
separated by commas; the last constant is terminated by a
space. If less than six digits are indicated for a constant, the
data is right justified in the word.A label, if used, acts as
the address of the first constant in the string. The letter B
must not be used after the constant in the Operand field; it is
significant only when defining an octal term in an instruction
other than OCT.

Examples:

1 5 10 15 20 25 30 35 40
----------------------------------------
OCT +0
OCT -2
NUM OCT 177,20405,-36
OCT 51,77777,-1,10101
OCT 107642,177077
OCT 1976 ILLEGAL: CONTAINS DIGIT 9
OCT -177777
OCT 177B ILLEGAL: CONTAINS CHARACTER B

The previous statements are stored as follows:

4-22

4.5 STORAGE ALLOCATION

The storage allocation statement reserves a block of memory
for data or for a work area.

------+-----+---------+--------
label BSS m comments

The BSS pseudo operation advances the program or base page
location counter according to the value of the operand. The
Operand field may contain any expression that results in a
positive integer. Symbols, if used, must be previously de-
fined in the program. The label, if given, is the name as-
signed to the storage area and represents the address of the
first word. The initial content of the area set aside by the
statement is unaltered by the loader.

4.6 ASSEMBLY LISTING CONTROL

Assembly listing control pseudo instructions allow the user to
control the assembly listing output during pass2 or 3 of the
assembly process. These pseudo instructions may be used only
with the source program is translated by the Extended Assem-
bler provided for 8K or larger machines (8,192-word memory
or larger).

------+-----+---------+--------
UNL comments

Output is suppressed from the assembly listing, beginning with
the UNL pseudo instruction and continuing for all instructions
and comments until either an LST or END pseudo instruction is
encountered. Diagnostic messages for errors encountered by
the assembler will be printed, however, The source statement
sequence numbers (printed in columns 1-4 of the source
program listing) are incremented for the instructions skipped.

4-23

------+-----+---------+--------
LST comments

The LST pseudo instruction causes the source program listing,
terminated by a UNL, to be resumed.

A UNL following a UNL, a LST following a LST, and a LST not
preceded by a NUL are not considered errors by the Assembler.

------+-----+---------+--------
SUP comments

The SUP pseudo instruction suppresses the output of additional
code lines from the source program listing. Certain pseudo
instructions, because they result in using subroutines, generate
more than one line of coding. These additional code lines are
suppressed by a SUP instruction until a UNS or the END pseudo
instruction is encountered. SUP will suppress additional code
lines in the following pseudo instructions:

ASC DIV FAD FSB
OCT DLD FDV MPY
DEC DST FMP

The SUP pseudo instruction may also be used to suppress the
listing of literals at the end of the source program listing.

------+-----+---------+--------
UNS comments

The UNS pseudo instruction causes the printing of additional
coding lines, terminated by a SUP, to be resumed.

4-24

A SUP preceded by another SUP, UNS preceded by UNS, or
UNS not preceded by a SUP are not considered errors by the
Assembler.

------+-----+---------+--------
SKP comments

The SKP pseudo instruction causes the source program listing
to be skipped to the top of the next page. The SKP instruction
is not listed, but the source statement sequence number is
incremented for the SKP.

------+-----+---------+--------
SPC n comments

The SPC pseudo instruction causes the source program listing
to be skipped a specified number of lines. The list output is
skipped n lines, or to the bottom of the page, whichever occurs
first. The n may be any absolute expression. The SPC
instruction is not listed but the source statement sequence
number is incremented for the SPC.

------+-----+---------+--------
HED m (heading)

The HED pseudo instruction allows the programmer to specify
a heading to be printed at the top of each page of the source
program listing.

The heading, m, a string of up to 56 ASCII characters, is printed
at the top of each page of the source program listing following
the occurrence of the HED pseudo instruction. If HED is
encountered before the NAM or ORG at the beginning of a
program, the heading will be used on the first page of the
source program listing. A HED instruction placed elsewhere
in the program causes a skip to the top of the next page.

The heading specified in the HED pseudo instruction will be
used on every page until it is changed by a succeeding HED
instruction.

The source statement containing the HED will not be listed, but
the source statement sequence number will be incremented.

4-25

4.7 ARITHMETIC SUBROUTINE CALLS

The members of this group of pseudo instructions request
the Assembler to generate calls to arithmetic subroutines [1]
external to the source program. These pseudo instructions
may be used in relocatable programs only. The Operand
field may contain any relocatable expression or an absolute
expression resulting in a value of less than 100(8).

------+-----+---------+--------
MPY m[,I] comment
=Dn
=Bn

Multiply the contents of the A-register by the contents of m
or the quantity defined by the literal and store the product in
registers B and A. B contains the sign of the product and the
15 most significant bits; A contains the least significant bits.

------+-----+---------+--------
DIV m[,I] comment
=Dn
=Bn

Divide the contents of registers B and A by the contents of m
or the quantity defined by the literal. Store the quotient in A
and the remainder in B. Initially B contains the sign and the 15
most significant bits of the dividend; A contains the least
significant bits.

------+-----+---------+--------
FMP m[,I] comment
=Fn

Multiply the two-word floating-point quantity in registers A
and B by the two-word floating-point quantity in locations m
and m+1 or the quantity defined by the literal. Store the two-
word floating-point product in registers A and B.

------+-----+---------+--------
FDV m[,I] comment
=Fn

Divide the two-word floating-point quantity in registers A and
B by the two-word floating-point quantity in locations m and
m+1 or the quantity defined by the literal. Store the two-
word floating-point quotient in A and B.

----------------------
[1] Not intended for use with DEX formatted numbers. For
such numbers JSB's to double precision subroutines must
be used. See Relocatable Subroutines Manual (02116-91780).

4-26

------+-----+---------+--------
FAD m[,I] comment
=Fn

Add the two-word floating point quantity in registers A and B
to the two-word floating point quantity in locations m and m+1
or the quantity defined by the literal. Store the two-word
floating point sum in A and B.

------+-----+---------+--------
FSB m[,I] comment
=Fn

Subtract the two-word floating point quantity in m and m+1
or the quantity defined by the literal from the two-word
floating point quantity in registers A and B and store the
difference in A and B.

------+-----+---------+--------
DLD m[,I] comment
=Fn

Load the contents of locations m and m+1 or the quantity
defined by the literal into registers A and B respectively.

------+-----+---------+--------
DST m[,I] comment
=Fn

Store the contents of registers A and B in locations m and m+1
respectively.

Each use of a statement from this group generates two words
of instructions. Symbolically, they could be represented as
follows:

JSB <.arithmetic pseudo operation>
DEF m[,I]

An EXT <.arithmetic pseudo operation> is implied preceding
the JSB operation.

In the above operations, the Overflow bit is set when one of
the following conditions occurs:

Integer overflow
Floating-point overflow or underflow
Division by zero.

Execution of any of the subroutines alters the contents
of the E-Register.

4-27

ASSEMBLER INPUT AND OUTPUT

The Assembler accepts as input a paper tape containing
a control statement and a source language program. A relocat-
able source language program may be divided into several
subroutines; the designation of these elements is optional.
The output produced by the Assembler may include a punched
paper tape containing the object programs, an object program
listing, and diagnostic messages.

5.1 CONTROL STATEMENT

The control statement specifies the output to be produced:

ASMB,p1,p2,...,pn

"ASMB," is entered in positions 1-5. Following the comma
are one or more parameters, in any order, which define the
output to be produced. The control statement must be termi-
nated by an end-of-statement mark, (CR)(LF).

The parameters may be any legal combinations of the follow-
ing starting in position 6:

A Absolute: The addresses generated by the Assembler
are to be interpreted as absolute locations in memory.
The program is a complete entity. It may not include
NAM, ORB, COM, ENT, EXT, arithmetic pseudo
operation statements or literals. The binary output
format is that specified for the Basic Binary Loader.

R Relocatable: The program may be located anywhere in
memory. Instruction operands are adjusted as neces-
sary. The binary output format is that specified for
the BCS Relocating loader.

B Binary output: A program is to be punched according
to one of the above parameters.

L Listing output: A program listing is to be produced either
during pass two or pass three (if binary output se-
lected) according to one of the above parameters.

5-1

T Table print: List the symbol table at the end of the
first pass. For the Extended Assembler: List
the symbol table in alphabetic order in three sections:
section 1 for on- character symbols, section 2 for
two- and three- character symbols, and section 3
for four- and five- character symbols.

N Include sets of instructions following the IFN pseudo
instruction.

Z Include sets of instructions following the IFZ pseudo
instruction.

F Accepted by the Assembler to provide compatibility with
DOS or DOS-M Assembler programs. F causes no action
in any other assemblers.

(F = Extended Arithmetic Unit/Floating Point;
X = Nonextended Arithmetic Unit;
No parameter - Extended Arithmetic Unit)

Either A or R must be specified in addition to any combination of
B, L, or T.

If a programmer wishes to assemble pass 1 of a source program to check
for errors, he can specify only an A or R to be the sole parameter of
the Assembler control statement, executing only pass 1. (This produces
pass 1 error messages without listing the program or providing an object
tape). Extended Assembler only.

The Assembler control statement must specifically request pass 2
operations (list or punch) in order for pass 2 to be executed. Lack of
pass 2 option information causes processing only of pass 1 errors. If a
C option is also provided, an automatic cross-reference symbol table is
done after pass 1 when operating in the MTS environment.

The control statement may be on the same tape as the source
program, or on a separate tape; or it may be entered via the
Teleprinter keyboard.

5-2

5.2 SOURCE PROGRAM

The first statement of the program (other than remarks or
a HED statement) must be a NAM statement for a relocatable
program or an ORG statement for indicating the origin of an
absolute program. The last statement must be an END state-
ment and may contain a transfer address for the start of a
relocatable program. Each statement is followed by an
end-of-statement mark.

5.3 BINARY OUTPUT

The punch output is defined by the ASMB control statement.
The punch output includes the instructions translated from the
source program. It does not include system subroutines re-
ferenced within the source program (arithmetic subroutine
calls, .IOC., .DIO., .ENTR, etc.)

5.4 LIST OUTPUT

Fields of the object program are listed in the following print
columns.

Columns Content
------- -------
1-4 Source statement sequence number gener-
ated by the Assembler

5-6 Blank

7-11 Location (octal)

12 Blank

13-18 Object code word in octal

19 Relocation or external symbol indicator

20 Blank

21-72 First 52 characters of source statement.

5-3

Lines consisting entirely of comments (i.e. * in column 1) are
printed as follows:

Columns Content
------- -------
1-4 Source statement sequence number

5-72 Up to 68 characters of comments

A Symbol Table listing has the following format:

Columns Content
------- -------
1-5 Symbol
6 Blank
7 Relocation or external symbol indicator
8 Blank
9-14 Value of the symbol

The characters that designate an external symbol or type of
relocation for the Operand field or the symbol are as follows:

Columns Content
------- -------
Blank Absolute
R Program relocatable
B Base page relocatable
C Common relocatable
X External symbol

At the end of each pass, the following is printed:

** NO ERRORS*
or
** nnnn ERRORS*

The value nnnn, indicates the number of errors.

NOTE: For complete operating instructions for the HP Assem-
bler or the extended Assembler, consult Software Operat-
ing Procedures, SIO Subsystems module (5931-1390)

5-4

ASSEMBLER INSTRUCTIONS

Symbols Meaning
------- -------
label Symbolic label, 1-5 alphanumeric characters and periods

m Memory location represented by an expression

I Indirect addressing indicator

C Clear flag indicator

(m,m+1) Two-word floating-point value in m and m+1

comments Optional comments

[ ] Optional portion of field

{ } One of set may be selected

P Program Counter

( ) Contents of location

A.n Bit n of A-register

B.n Bit n of B-register

b Bit positions in B- and A-register
___
(A) Complement of contents of Register A
___
(B) Complement of contents of Register B

(AB) Two-word floating-point value in registers A and B

sc Channel select code represented by an expression

Jump and Increment-Skip

ISZ m[,I] (m)+1 -> m; then if (m) = 0, execute P+2
otherwise execute P+1

JMP m[,I] Jump to m; m -> P

JSB m[,I] Jump subroutine to m; P + 1 -> m; m + 1 -> P

Add, Load and Store

ADA m[,I] (m) + (A) -> A
lit

ADB m[,I] (m) + (B) -> B
lit

LDA m[,I] (m) -> A
lit

LDB m[,I] (m) -> B
lit

STA m[,I] (A) -> m

STB m[,I] (B) -> m

Logical

AND m[,I] (m) /\ (A) -> A
lit

XOR m[,I] (m) -\/- (A) -> A
lit

IOR m[,I] (m) \/ (A) -> A
lit

CPA m[,I] If (m) != (A), execute P + 2, otherwise
lit execute P + 1

CPB m[,I] If (m) != (B), execute P + 2, otherwise
lit execute P + 1

Shift-Rotate

CLE 0 -> E
ALS Shift (A) left one bit, 0 -> A.0, A.15 unaltered
BLS Shift (B) left one bit, 0 -> B.0, B.15 unaltered
ARS Shift (A) right one bit, (A.15) -> A.14
BRS Shift (B) right one bit, (B.15) -> B.14
RAL Rotate (A) left one bit
RBL Rotate (B) left one bit

B-2

Shift-Rotate (Continued)

RAR Rotate (A) right one bit
RBR Rotate (B) right one bit
ALR Shift (A) left one bit, 0 -> A.15
BLR Shift (B) left one bit, 0 -> B.15
ERA Rotate E and A right one bit
ERB Rotate E and B right one bit
ELA Rotate E and A left one bit
ELB Rotate E and B left one bit
ALF Rotate A left four bits
BLF Rotate B left four bits
SLA If (A.0) = 0, execute P + 2, otherwise execute P + 1
SLB If (B.0) = 0, execute P + 2, otherwise execute P + 1

Shift-Rotate instructions can be combined as follows:

ALS ALS
ARS ARS
RAL RAL
RAR , CLE , SLA , RAR
ALR ALR
ALF ALF
ERA ERA
ELA ELA

BLS BLS
BRS BRS
RBL RBL
RBR , CLE , SLB , RBR
BLR BLR
BLF BLF
ERB ERB
ELB ELB

CLB 0's -> B
___
CMA (A) -> A
___
CMB (B) -> B

CCA 1's -> A

CCB 1's -> B

CLE 0 -> E
___
CME (E) -> E
B-3

CCE 1 -> E
SEZ If (E) = 0, execute P + 2, otherwise execute P + 1
SSA If (A.15) = 0, execute P + 2, otherwise execute P + 1
SSB If (B.15) = 0, execute P + 2, otherwise execute P + 1
INA (A) + 1 -> A
INB (B) + 1 -> B
SZA If (A) = 0, execute P + 2, otherwise execute P + 1
SZB If (B) = 0, execute P + 2, otherwise execute P + 1
SLA If (A.0) = 0, execute P + 2, otherwise execute P + 1
SLB If (B.0) = 0, execute P + 2, otherwise execute P + 1
RSS Reverse sense of skip instructions. If no skip
instructions precede, execute P + 2

Alter-Skip instructions can be combined as follows:

CLA CLE
CMA , SEZ , CME , SSA , SLA , INA , SZA , RSS
CCA CCE

CLB CLE
CMB , SEZ , CME , SSB , SLB , INB , SZB , RSS
CCB CCE

INPUT/OUTPUT, OVERFLOW, and HALT

Input/Output

STC sc [,C] Set control bit.sc, enable transfer of one element of
data between device.sc and buffer.sc

CLC sc [,C] Clear control bit.sc; If sc = 0 clear all control bits

LIA sc [,C] (buffer.sc) -> A

LIB sc [,C] (buffer.sc) -> B

MIA sc [,C] (buffer.sc) \/ (A) -> A

MIB sc [,C] (buffer.sc) \/ (B) -> B

OTA sc [,C] (A) -> buffer.sc

OTB sc [,C] (B) -> buffer.sc

STF sc Set flag bit.sc; If sc = 0, enable interrupt system.
sc = 1 sets overflow bit.

CLF sc Clear flag bit.sc; If sc = 0, disable interrupt system.
If sc = 1, clear overflow bit.

SFC sc If (flag bit.sc) = 0, execute P + 2, otherwise execute
P + 2. If sc = 1, test overflow bit.

SFS sc If (flag bit.sc) = 1, execute P + 2, otherwise execute
P + 2. If sc = 1, test overflow bit.

B-4

Overflow

CLO 0 -> overflow bit

STO 1 -> overflow bit

SOC [C] If (overflow bit) = 0, execute P + 2,
otherwise execute P + 1

SOS [C] If (overflow bit) = 1, execute P + 2,
otherwise execute P + 1

Halt

HLT [sc [,C]] Halt computer

EXTENDED ARITHMETIC UNIT (requires EAU version of Assembler or
Extended Assembler)

MPY m[,I] (A) * (m) -> (B and A)
lit

DIV m[,I] (B and A) / (m) -> A, remainder -> B
lit

DLD m[,I] (m) and (m+1) -> A and B
lit

DST m[,I] (A) and (B) -> m and m+1
lit

ASR b Arithmetically shift (BA) right b bits,
B.15 extended

ASL b Arithmetically shift (BA) left b bits,
B.15 unaltered, 0's to A.0

RRR b Rotate (BA) right b bits

RRL b Rotate (BA) left b bits

LSR b Logically shift (BA) right b bits, 0's to B.15

LSL b Logically shift (BA) left b bits, 0's to A.0

B-5

PSEUDO INSTRUCTIONS

ASSEMBLER CONTROL

NAM [name] Specifies relocatable program and its name.

ORG m Gives absolute program origin or origin for a segment
of relocatable or absolute program.

ORR Reset main program location counter at value existing
when first ORG or ORB of a string was encountered.

ORB Defines base page portion of relocatable program.

END [m] Terminates source language program. Produces transfer
to program starting location, m, if given.

REP r Repeat immediately following statement r times.
<statement>

IFN Include statements in program if control statement
<statements> contains N.
XIF

IFZ Include statements in program if control statement
<statements> contains Z.
XIF

OBJECT PROGRAM LINKAGE

COM name1 [ (size1) ] [, name2 [ (size2) ] [ , ... ]
Reserves a block of common storage locations. name
identifies segments of block, each of length size.

ENT name1 [ , name2 ] [ , ... ]
Defines entry points, name, that may be referred to
by other programs

EXT name1 [ , name2 ] [ , ... ]
Defines external locations, name, which are labels
of other programs, referenced by this program.

ADDRESS AND SYMBOL DEFINITION

label DEF m[,I] Generates a 15-bit address which may be referenced
indirectly through the label.

label ABS m Defines a 16-bit absolute value to be referenced
by the label.

label EQU m Equates the value, m, to the label.

B-6

CONSTANT DEFINITION

ASC n,<2n characters>
Defines a string of 2n ASCII characters

DEC d1 [, d2 ] [, ... ]
Records a string of decimal constants of the form:
Integer: +/-n
Floating-point: +/-n.n +/-n. +/-nE+/-e
+/-n.E+/-e +/-.nE+/-e
DEX d1 [, d2 ] [, ...]
Records a string of extended precision
decimal constants of the form:
Floating-point: +/-n +/-n.n
+/-n. +/-.n
+/-nE+/-e +/-n.nE+/-e
+/-n.E+/-e +/-.nE+/-e
OCT o1 [, o2 ] [, ...]
Records a string of octal constants of the
form: +/-oooooo

STORAGE ALLOCATION

BSS m Reserves a storage area of length, m.

ARITHMETIC SUBROUTINE CALLS REQUESTS [2]

MPY m[,I] (A) * (m) -> (BA) [1]
lit

DIV m[,I] (BA) / (m) -> A , remainder -> B [1]
lit

FMP m[,I] (AB) * (m,m+1) -> AB
lit

FDV m[,I] (AB) / (m,m+1) -> AB
lit

FAD m[,I] (AB) + (m,m+1) -> AB
lit

FSB m[,I] (AB) - (m,m+1) -> AB
lit

DLD m[,I] (m) and (m+1) -> A and B [1]
lit

DST m[,I] (A) and (B) -> (m) and (m+1) [1]

------------------------
[1] For configurations including Extended Arithmetic Unit, these mnemonics
generate hardware instructions when the EAU version of the Assembler
or Extended Assembler is used.

[2] Not intended for use with DEX formatted numbers. For such numbers,
JSB Machine Instructions must be used.

B-7

ASSEMBLY LISTING CONTROL

UNL Suppress assembly listing output.

LST Resume assembly listing output.

SKP Skip listing to top of next page.

SPC n Skip n lines on listing.

SUP Suppress listing of extended code lines (e.g.
as produced by subroutine calls).

UNS Resume listing of extended code lines.

HED <heading> Print <heading> at top of each page, where <heading>
is up to 56 ASCII characters.

B-8

ALPHABETIC LIST OF INSTRUCTIONS

ABS Define absolute value
ADA Add to A
ADB Add to B
ALF Rotate A left 4
ALR Shift A left 1, clear sign
ALS Shift A left 1
AND "AND" to A
ARS Shift A right 1, sign carry
ASC Generate ASCII characters
ASL Arithmetic long shift left
ASR Arithmetic long shift right
BLF Rotate B left 4
BLR Shift B left 1, clear sign
BLS Shift B left 1
BRS Shift B right 1, carry sign
BSS Reserve a block of storage start at symbol
CCA Clear and complement A (1's)
CCB Clear and complement B (1's)
CCE Clear and complement E (set E = 1)
CLA Clear A
CLB Clear B
CLC Clear I/O control bit
CLE Clear E
CLF Clear I/O flag
CLO Clear overflow bit
CMA Complement A
CMB Complement B

C-1

CME Complement E
COM Reserve block of common storage
CPA Compare to A, skip if unequal
CPB Compare to B, skip if unequal
DEC Defines decimal constants
DEF Defines address
DEX Defines extended precision constants
DIV Divide
DLD Double load
DST Double store
ELA Rotate E and A left 1
ELB Rotate E and B left 1
END Terminate program
ENT Entry point
ERA Rotate E and A right 1
ERB Rotate E and B right 1
EQU Equate symbol
EXT External reference
FAD Floating add
FDV Floating divide
FMP Floating multiply
FSB Floating subtract
HED Print heading at top of page
HLT Halt
IFN When N appears in Control Statement, assemble
ensuing instructions
IFZ When Z appears in Control Statement, assemble
ensuing instructions
INA Increment A by 1
INB Increment B by 1
IOR Inclusive "or" to A
ISZ Increment, then skip if zero
JMP Jump

C-2

JSB Jump to subroutine
LDA Load into A
LDB Load into B
LIA Load into A from I/O channel
LIB Load into B from I/O channel
LSL Logical long shift left
LSR Logical long shift right
LST Resume list output (follows a UNL)
MIA Merge "or" into A from I/O channel
MIB Merge "or" into B from I/O channel
MPY Multiply
NAM Names relocatable program
NOP No operation
OCT Defines octal constant
ORB Establish origin in base page
ORG Establish program origin
ORR Reset program location counter
OTA Output from A to I/O channel
OTB Output from B to I/O channel
RAL Rotate A left 1
RAR Rotate A right 1
RBL Rotate B left 1
RBR Rotate B right 1
REP Repeat next statement
RRL Rotate A and B left
RRR Rotate A ad B right
RSS Reverse skip sense
SEZ Skip if E = 0
SFC Skip if I/O flag = 0 (clear)
SFS Skip if I/O flag = 1 (set)
SKP Skip to top of next page

C-3

SLA Skip if LSB of A = 0
SLB Skip if LSB of B = 0
SOC Skip if overflow bit = 0 (clear)
SOS Skip of overflow bit = 1 (set)
SPC Space n lines
SSA Skip if sign A = 0
SSB Skip if sign B = 0
STA Store A
STB Store B
STC Set I/O control bit
STF Set I/O flag
STO Set overflow bit
SUP Suppress list output of additional code lines
SWP Switch the (A) and (B) ???
SZA Skip if A = 0
SZB Skip if B = 0
UNL Suppress list output
UNS Resume list output of additional code lines
ZIF Terminate an IFN or IFZ group of instructions
XOR Exclusive "or" to A

C-4

SAMPLE PROGRAMS

Following are two sample programs, the second of which implements
several options of the Extended Assembler.

PARTS FILE UPDATE

A master file of parts is updated by a parts usage list to produce a
new master parts file. A report, consisting of the parts used and their
cost, is also produced.

The organization of the files is a follows:

Parts Master Files (PRTSM)

---------------------------------------------
| Identification | Quantity | Cost/Item |
---------------------------------------------

Identification fields of the Parts Master Files exists in ASCII although
the entire record is read ans written in binary.

Parts Usage FIle (PRTSU)

-------------------------------
| Identification | Quantity |
-------------------------------

The parts usage file has been recorded in ASCII.

Parts Cost Report (PRTSC)

-----------------------------------------------------------------------
| Identification | //// | Quantity used | //// | $ | Cost for Qty |
-----------------------------------------------------------------------

The Parts Cost Report is recorded in ASCII with spacing and editing for
printing.

The sample program reads and writes the files, adjusts the new stock levels,
and calculates the cost. External subprograms perform the binary-to-decimal
and decimal-to-binary conversions and handle unrecoverable input/output
errors, invalid data conditions, and normal program termination. Input/output
operations are performed using the Basic Control System input/output sub-
routine, .IOC.

D-1

SAMPLE PROGRAM
GENERAL FLOW CHART

D-2

SAMPLE ASSEMBLER SYMBOL TABLE OUTPUT

D-3

SAMPLE ASSEMBLER LIST OUTPUT

D-4

NAM UPDTE
START NOP
JMP OPEN
ORB ASSIGN STORAGE & CONSTANTS TO BP
PRTSM BSS 4 MASTER PARTS FILE - BINARY.
PRTSU BSS 4 PARTS USAGE LIST - ASCII.
PRTSC BSS 11 PARTS USAGE REPORT - ASCII.
EOTS1 JMP READM
EOTS2 JMP WRITN
MTEMP BSS 1
UTEMP BSS 1
SWTMP BSS 2
SPACS ASC 2,
DLRSG ASC 1, $
A EQU 0
B EQU 1
EXT .IOC. PERFORM I/O OPERATIONS USING BCS
* I/O CONTROL ROUTINE.
EXT BCONV ENTRY POINT FOR DECIMAL(ASCII)
* TO BINARY CONVERSION SUBPROGRAM.
EXT DCONV ENTRY POINT FOR BINARY TO
* DECIMAL(ASCII) CONVERSION SUB-
* PROGRAM
EXT ABORT ENTRY POINT FOR SUBPROGRAM WHICH
* HANDLES UNRECOVERABLE I/O ERRORS
* OR INVALID DATA.
EXT HALT END OF PROGRAM SUBROUTINE.
COM DTOBI(2),DTOBO,BTODI(2),BTODO(2)
* COMMON STORAGE LOCATIONS USED TO
* PASS DATA BETWEEN MAIN PROGRAM
* AND CONVERSION SUBPROGRAMS.
ORR RESETS PLC AFTER USE OF ORB AT
* BEGINNING OF PROGRAM
OPEN NOP
SPCFL DLD SPACS STORES EDITING CHARACTERS IN
DST PRTSC+2 OUTPUT AREA FOR PARTS COST
DST PRTSC+6 REPORT.
LDA DLRSG
STA PRTSC+8
READU JSB .IOC. READ ONE RECORD FROM USAGE LIST
OCT 10001 LOCATED ON STANDARD UNIT 1
JMP RJCTU (TELEPRINTER INPUT). PRTUS IS
DEF PRTSU ADDRESS OF STORAGE AREA; AREA IS
DEC 4 4 WORDS LONG.
CXSTU JSB .IOC. CHECK STATUS OF UNIT 1.
OCT 40001
RAL
SSA
JMP CHKSTU IF BUSY, LOOP UNTIL FREE.
RAL
SSA
JMP *+2
JMP READM IF COMPLETE, TRANSFER TO SECTION
* WHICH READS MASTER FILE RECORD.
ALF,ALF TEST END OF TAPE STATUS BIT
RAL (ORIGINAL BIT 05).
SSA
JMP EOTU IF SET, GO TO EOT PROCEDURE.
JMP ABORT IF NOT SET, SOME ERROR CONDITION
* (UNRECOVERABLE) EXISTS.
RJCTU SSB CHECK CAUSE OF REJECT. IF UNIT
JMP READU BUSY LOOP UNTIL FREE. ANY OTHER
JMP ABORT CAUSE IS UNRECOVERABLE ERROR.
EOTU LDA OETS1 IF END OF USAGE FILE, ALTER
STA OPEN PROGRAM SEQUENCE TO BYPASS
LDA EOTS2 SECTIONS THAT READ AND PROCESS
STA COMPR USAGE FILE. PRINT MESSAGE ON
JSB .IOC. TELEPRINTER INDICATING EOT.
OCT 20002
JMP EOTU+4
DEF MSGU
DEC 9
MSGU ASC 9,END OF USAGE FILE
JMP READM
READM JSB .IOC. READ A RECORD FROM MASTER PARTS
OCT 10105 FILE ON STANDARD UNIT 05(PUNCHED
JMP RJCTM TAPE READER). PRTSM IS ADDRESS
DEF PRTSM OF STORAGE AREA; AREA IS 4 WORDS
DEF 4 LONG. RECORD IS IN BINARY FORMAT
CKSTM JSB .IOC. CHECK STATUS OF UNIT 5.
OCT 40005
SSA
JMP CKSTM IF BUSY, LOOP UNTIL FREE.
RAL
SSA
JMP *+2
JMP COMPR IF COMPLETE, TRANSFER TO EITHER
ALF,ALF PROCESSING OR WRITE OUTPUT
RAL DEPENDING ON SETTING OF COMPR.
SSA TEST FOR END OF TAPE.
JMP EOTM IF END, GO TO EOT PROCEDURE.
JMP ABORT IF NOT, AN UNRECOVERABLE ERROR
* EXISTS.
RJTCM SSB CHECK CONTENTS OF B FOR CAUSE OF
JMP READM REJECT. IF UNIT BUSY, LOOP UNTIL
JMP ABORT FREE, OTHERWISE I/O ERROR EXISTS
EOTM LDA HLTSW ALTER PROGRAM SEQUENCE TO HALT
STA CKSTN+7 EXECUTION AFTER LAST RECORD IS
JSB .IOC. WRITTEN PRINT MESSAGE
OCT 20002 INDICATING END OF MASTER INPUT.
JMP EOTM+2
DEF MSGM
DEC 15
MSGM ASC 15,END OF MASTER PARTS FILE INPUT
JMP COMPR
HLTSW JMP HALT END OF PROGRAM SUBROUTINE
COMPR NOP
JSB CONUI CONVERT ID NUMBER FIELDS OF
JSB CONVM MASTER AND USAGE FILES TO BIN.
LDA UTEMP LOAD THESE FIELDS FROM TEMPORARY
LDB MTEMP STORAGE.
CPA B COMPARE
JMP PROCM IF EQUAL, JUMP TO PROCESSING
CMB,INB IF ID NUMBER OF MASTER GREATER
ADA B THAN ID NUMBER OF USAGE, DATA IN
SSA USAGE FILE ERRONEOUS. TERMINATE
JMP ABORT RUN.
LDA *+3 IF ID MASTER LESS THAN ID USAGE,
STA CKSTN+7 ALTER SEQUENCE: READ NEXT MASTER
JMP WRITN RECORD IMMEDIATELY AFTER WRITING
JMP READM CURRENT MASTER RECORD.
PROCM JSB CONU2 CONVERT QUANTITY FIELD OF USAGE
LDA PRTSM+2 FILE TO BINARY AND SUBTRACT FROM
LDB UTEMP+1 QUANTITY FIELD OF MASTER AND
CMB,INB STORE RESULT
ADA B
STA PRISM+2
PROCC DLD PRTSU STORE ID OF PARTS USED IN REPORT
DST PRTSC FILE STORAGE AREA.
DLD PRTSU+2 STORE QUANTITY OF PARTS USED IN
DST PRTSC+4 REPORT FILE STORAGE AREA
LDA PRTSM+3 COMPUTE COST OF PARTS USED.
MPY UTEMP+1
STA SWTMP+1
STB SWTMP
JSB CONVC CONVERT RESULT TO DECIMAL
DLD SWTMP
DST PRTSC+9 STORE IN REPORT FILE AREA.
LDA *+3 ALTER SEQUENCE: READ NEXT USAGE
STA CKSTN+7 RECORD AFTER WRITING CURRENT
JMP WRITC MASTER RECORD.
JMP READU
CONVM NOP
DLD PRTSM STORE ID FIELDS IN COMMON
DST DTOBI LOCATIONS TO BE PROCESSED BY
JSB BCONV CONVERSION SUBPROGRAM. ON
LDA DTOBO COMPLETION, STORE RESULTS IN
STA MTEMP LOCATIONS USED BY PROCESSING
JMP CONVM,I SECTIONS. CONVM APPLIES TO ID OF
CONU1 NOP MASTER PARTS FILE; CONU1, TO ID
DLD PRTSU OF USAGE; CONU2, TO QUANTITY OF
DST DTOBI USAGE; AND CONVC, TO COST OF
JSB BCONV PARTS(THIS IS A BINARY TO
LDA DTOBO DECIMAL CONVERSION).
STA UTEMP
JMP CONU1,I
CONU2 NOP
DLD SWTMP
DST BTODI
JSB DCONV
DLD BTODO
DST SWTMP
JSB CONVC,I
WRITC JSB .IOC. WRITE ONE RECORD OF PARTS COST
OCT 20102 REPORT ON STANDARD UNIT 2
JMP RJCTC (TELEPRINTER OUTPUT). PRTSC IS
DEF PRTSC ADDRESS IN STORAGE AREA; AREA IS
DEC 11 11 WORDS LONG. RECORD IS IN ASCII
CKSTC JSB .IOC. CHECK STATUS OF UNIT 2
OCT 40002
SSA
JMP CKSTC
RAL
SSA
JMP ABORT TERMINATE IF ANY I/O ERROR.
JMP WRITN IF COMPLETE, TRANSFER TO WRITN
RJCTC SSB IF BUSY, LOOP UNTIL FREE.
JMP WRITC TERMINATE ON ANY OTHER REJECT
JMP ABORT CONDITION
WRITN JSB .IOC. WRITE ONE RECORD (BINARY) OF
OCT 20104 NEW MASTER PARTS LIST ON UNIT 4
JMP RJCTN (TAPE PUNCH). PRTSM (INPUT AREA)
DEF PRTSM IS ALSO USED AS OUTPUT AREA.
DEC 4
CKSTN JSB .IOC. CHECK STATUS OF UNIT 4.
OCT 40004
SSA
JMP CKSTN IF BUSY, LOOP UNTIL FREE.
RAL
SSA
JMP ABORT
JMP READU
RJCTN SSB IF BUSY, LOOP UNTIL FREE, OTHER-
JMP WRITN WISE TERMINATE.
JMP ABORT
END START