
TABLE OF CONTENTS
Page
General
Description
High-Speed
Introduction
HSM
Hexadecimal
Exercise
Data
and
Instruction
Data
Unpacked
Edited
Machine
Exercise
Interrupt
Introduction
Programming
Processing
Interrupt
Types
I/O
Interrupt
Operation
Arithmetic
Elapsed
Inhibiting
Exercise
Summary
. . . . • • • • • . . . • . • . • • . • . • . . • • • . • • • • • . • . . • • • • . • . . . . • • . • . . 1
Memory
• • . • . . . • • • • . • . • • . • . • . • . • . • . . • • • . • • . • • • . • • • • • • . . . • • • • • • 3
.••..•.•••...•.•....•.•.••.•..•••..•..••••••..••••••.•..
Addressing
..••••••..•.•••••.••.••.•.•.•.•..•.••.•..••.•••...•..
Numbering
System
• . . • • • . • . . • . • . . • • • . • . • • • • . • • • • . . • • • . . • • • • • • 4
.••••••......•.•.•.•.••••••.•.•.••••••.•••••••••..•.•..•••
Formats
Format
Format
Instruction
Format
. . . . • . • . • . • . • • • • • . • . • • . • • • • • • • • • • • • . • . • • • • • • • • • • . • • • • . • 6
.•.•...••••••......•..•..•••..•.•..•.•.•••.•.•.••.••••
........•.•.••.•••••.•.•..•.•••••..•.•.••••...••
.•.•..•••••••••.•.•••••••.••••.••••.••••.••.••••.•••
Format
•.•...••.••••••••...••.••.•.••.•.•.••....••••
.•••.•..•.•..••..••••••••••••.••••••••.•..•.••••••..••••.•
.••..•.•..•••.•.••.••••.••••.•.....••.•••..••••••.•.••.••.•.•
••.•.•.•..•••....•.•.•..•..•..•.•.....••.•.••..••••..•..
State
of
Interrupt
Code
Timer
Interrupt
States.
State
• . • . • . • • • . . . • . . . . . . • • • • • • . • . • . . • • . • • . . • • • • . • • . . . • • • • • . • 9
•.
Overflow
. . • . • • • . • • . • . • . • . • . • • • . • • • • . • • . • . • • . • • • • • • . • • • • • • • 9
. . . . . . . . • . . . . . . • . . . . • • • . • . • . . • . . . . . . . . . . . • . . . . . . . • . • • 9
. • • . • • . . . . . . . • . • . • . . . . • . . . . . . . . . . . • • • • • • . • . . • . . • . . . • 9
. . • • • . . • • • • • • . • . • . • • . • • • • • . . • . • . . . . . . • • . • . • . • . • . . • . • • 9
Trap
.•...•••••.•.•.•••••••........•..••.....•........•
and
Divide
Interrupt.
Exception
. . . . . • . • . . . . . • . • . . . . . . . • . . . . . . . . . . . .
. . . . . • . • . . . • . . . . . . . . . • . • . . . . • . . . • • • • • . . . . . . . • . . 11
•••..•••.••.•..•.•..••....•...•....•.•••......•....
...•....•.............•.................•......•...•....•.
of
Interrupt
Logic
..•..•..•.•...•...•.•......••.•....•..•......
3
3
5
6
6
6
7
7
9
9
10
10
11
11
12
Elapsed
Time
Introduction
Format
Addressing
Self-Defining
Expressions
Implied
Assembler
Define
Origin
Constant
Program
Run
Equate
Base
Extended
Exercise
Clock.
to
the
Requirements
• • • • . • • • • • • • . • • • . • • • . . • . • . • . • • • . • • • . • • • • • • . . . • . • • • • . .
RCA
70/25
Assembly
Language . ..•
• • • . • . • • • . • . • • • . • • • . • . . • • . • • •
•••.•.•••.•.•••.•.•••...•••.••••.•••.••.•..••••..
. . • • • • . • • . • • • • . • • • . . • • • . • . • . • • • • • . • . . • . • • • . • • • • • • . • • • . • • •
Values
•••••.••••.•••••.•.•.•••.••.••••.•••••••••.•..•.•.
• . • • • . • . • • • • • • • . . • • • . . . • . • . • . • . • • • • • . . • . • • • • • • • • • . • • • • . . 16
Lengths
and
Register
..........•.•.•.....•..•...•.•......•.•.•...•.....•.•
Controlling
Storage
Code
Definition
Linking
Segment
Code
Mnemonic
Codes
(DS)
•.••.•••..••••••••.•...•••.••••...••••..•••.
.•.•.•.••..•.•.•••••••.•.••••.••••••••.•..•.•.••
(ORG) • . • . . . • . • . • . . • • . • • . . . . . . . • • . . • . • . • • . . • . . • . . . . . . • •
(DC)
Codes
Controlling
(EQU)
Controlling
Instructions
...•.•.•...•.••.••.•.....••...
(ENTRY
and
Codes
EXTRH)
(START,
.•.•.•........
END,
....•....•.........•........•..•.....•.......•••
Codes
(USING, DROP)
.........•..................
. • . . . • . • . • . • • . . • . • . . . . . . . . . . . • . . • • . • . . . •
CSECT)
. . . . . . . . . . . . . . . . • . . 20
0 • • • • • • • • • • • • • •
0 • • • • • • • • • • • • • • •
.....•.•.•.•.......•...•......•.........•.................
13
14
14
14
16
17
17
18
18
18
19
21
21
21
22

TABLE
OF
CONTENTS
(Continued)
Page
Instruction
Data
Move
Packing
Decimal
Arithmetic
Decimal
Decimal
Decimal
Exercises
Data
Editing
Examples
Exercises
Comparison
Compare
Compare
Branch
Branch
Branch
Set
P2
Exercises
Load
and
Load
Store
Complement
Movement
Character
Exercises
and
Exercises
Add (AP)
Multiply
Divide
.............
Instruction
..
......
and
Branching
Logical
Decimal
on
Condition
and
Link
on
Count
Register
Store
Instructions
Multiple
Multiple
Instructions
(MVC)
....
Unpacking
.....
Instructions
and
Subtract
(MP) . . . . . . .
(DP)
........
(ED)
.
Instructions
(C
LC) .
(CP)
(BC)
(BAL) .
(BCT) .
(STP2) .
(LM) .
(STM) . .
Data
(PACK
(SP)
24
24
24
25
and
UNPK).
26
27
29
29
30
.
.
31
31
33
34
35
37
37
37
38
38
39
39
39
41
41
41
Binary
Arithmetic
Binary
Exercise
Logical
Instructions
Logical
Logical
Exclusive
Use
of
Test
Under
Data
Translation,
InputlOutput
Introduction.
Read
Instructions
Writing
Controlling
Error
Flow
Chart
Standard
Sensing
Peripheral
Summary
Example
Exercise
Instructions
Add (AB)
and
Subtract
....
And
(NC) .
Or
(OC)
Or
(XC)
Logicals
Mask
Instruction
Translate
. . . . . . . . . . . .
. . . . . . . . .
(RDF)
Data
(WR)
and
Peripheral
Recognition
of
Device
Exceptional
Unit
of
1/0
of
110
Basic
Byte
Sense
Logic
Coding
. . . . . . .
II
Conditions
........
.
(TM).
(TR)
and
(RDR)
(WRE) .
Devices
0
Logic.
.....
Bytes
..
.
.
(SB) .
.
42
42
42
45
45
45
45
46
.
47
47
49
49
49
50
50
51
52
53
53
54
55
56
57
ii

FOREWORD
70/25
This
manual
mayvaryinlengthfrom
outside
depending
recent
self-study.
Principal
self-study
is
designed
assignments
upon
the
programming
references
situations
1.
2.
TRAINING
for
use
about
15
and
work
experience
experience
which
are:
70/25
70/25
of
should
Assembly
System
in
formal
classroom
sessions)
the
student.
may
find
be
Manual
Reference
MANUAL
training
hours
to
used
(with
45
hours
People
the
in
either
Manual
programs
text
appropriate
or
with
good
helpful
formal
which
more,
and
in
or
iii

GENERAL
DESCRIPTION
INTRODUCTION
The
RCA
70/25
Spectra
70
Data
small-to-medium
with
communications
high-volume
capabilitie
70/25
The
RCA
stored
Speed
the
appropriate
Systems
HIGH-SPEED
The
High-Speed
device
grams
16,384,
smallest
of
eight
location
consisting
instruction,
register.
0ry
address.
The
Memory
the
time
a
memory
in
storage.
message
s.
PROCESSOR
70/25
program,
Magnetic
standard
MEMORY
that
provides
and
data.
32,768,
addressable
information
maybe
of
two
and a base
The
it
takes
register
is
the
intermediate
Processing
scale
gear,
data
the
series.
processor.
70/25
switching
Processor
digital
Core
Memory,
Input/Output
Interface
Memory
storage
The
or
65,536
unit
bits
accessed
is a general-purpose,
machine
Program
logic
Unit.
(HSM)
and
memory
bytes.
in
memory,
and a parity
with a 16-bit
parts: a displacement
address
sum
of
the
two
form
Cycle
is
1.
5
microseconds,
to
transfer
and
four
to
regenerate
member
It
is a powerful
has
high-speed,
or
remote
that
includes
Control,
for
the
is a magnetic
work
area
capacity
A
and
bit.
binary
carried
stored
an
effective
bytes
in a general
from
of
Equipped
processing
High-
Spectra
core
for
pro-
is
either
byte
is
consists
Each
byte
address
in
mem-
which
HSM
the
bytes
the
and
70
the
an
is
to
70/25
hardware.
ence
of
interrupt
the
Interrupt
INSTRUCTION COMPLEMENT
The
RCA
70/25
instructions
1.
DATA
HANDLING
The
data-handling
ment
of
data
without
or
late
changing
edited
for
instruction
conditions,
State.
Order
which
fields
format
printing
facilitates
It
automatically
Code
can
be
instructions
within
or
during
validation.
2.
ARITHMETIC
This
set
and
Divide
Subtract
to
perform
3.
DECISION
The
decision
comparing
the
branching
Condition
and
Link
simplify
includes
instructions,
operations.
Boolean
of
Code
and
subroutine
INSTRUCTIONS
Decimal
as
It
also
Operations
AND
CONTROL
and
control
both
Decimal
to a location
Indicator.
Branch-Qn-Count
linkage,
coding.
4.
INPUT/OUTPUT
senses
and
transfers
consists
divided
HSM.
it
the
code
into
four
allow
for
Data
may
can
be
packed,
movement. A Trans-
conversion
Add,
Subtract,
well
as
Binary
incorporates
on
bit
structures.
instructions
and
in
HSM
Also
included
allow
Binary
according
instructions
and
control
the
control
of
thirty-one
classeso
the
be
unpacked
and
Multiply
Add
the
fields,
are
Branch
of
iterative
pres-
movemoved
data
and
ability
for
the
and
to
that
to
a
PROGRAM CONTROL
The
Program
the
program
be
interpreted
only
after
process
of
the
instruction
staticizing.
then
executed
AUTOMATIC
The
RCA
tions
in
sing
State
State
is
that
causes
the
Interrupt
stored
it
of
interpreting
An
by
INTERRUPT
70/25
one
of
and
the
normal
interrupt
State.
Control
and
has
instruction
the
can
two
the
executes
in
the
HSM.
executed
been
in
and
the
by
brought
placing
proper
Program
staticize
and
programming
Interrupt
mode
will
State.
of
operation. A condition
transfer
Interrupt
the
An
the
Program
out
registers
is
first
Control
execute
states;
is
mechanized
instructions
instruction
of
HSM.
the
components
staticized
logic.
all
the
The
Processing;
the
computer
Control
is
called
instruc-
Proces-
in
of
can
The
and
to
the
Read
and
Write
the
processor
to
the
70/25.
to
control
from
INSTRUCTION FORMAT
There
70/25;
tion.
the
error
are
six-byte,
The
operation
remaining
storage
addresses,
instructions
and
Included
devices
conditions.
three
four-byte,
first
byte
code.
Depending
byte~
refer
all
basic
identification.
DATA
FORMAT
The
basic
unit
of
storage
peripheral
are
the
and
to
instruction
of
every
to
field
or
contain
transfer
data
equipment
necessary
recognize
instructions
and
formats
and a two-byte
instruction
on
the
instruction,
lengths,
register
peripheral
is
the
byte,
between
on-line
recover
instruc-
which
in
the
is
the
the
and
device
can

represent,
or
numeric
packed
Extended
(EBCDIC) .
INPUT
The
devices
format.
/OUTPUT
RCA
through
in
the
unpacked
character,
Data
is
Binary-Coded-Decimal
70/25
communicates
eight
I/O
format,
or
two
represented
channels.
numeric
Interchange
with
one
digits
in
HSM
peripheral
alphabetic
in
the
in
the
Code
Each
peripheral
electronics
the
status
generated
Each
channel
ing
execution
processor.
in
the
system
powerful
in
of
the
by
an
is a separate
overlap
An
II
overlap
device
order
to
device,
I/O
command.
0
termination
to
facilitate
capabilities.
contains
transmit
and any
simultaneous
with
other
interrupt
efficient
its
own
to
the
error
mode,
channels
use
control
processor
conditions
allow-
and
is
included
of
these
the
2

HIGH-SPEED
MEMORY
INTRODUCTION
The
RCA
70/25
(HSM)
planes.
(4 x 64 x 64
sable
information
Bit
Bit
Four
register
may
Each
unit
Identification
(X
= 0
or
1)
bytes
of
and
consist
plane
bytes).
in
bits
microseconds.
side
or
in
parallel.
MEMORY
REGISTER
0
1
2
magnetic
of
contains
The
memory,
and a parity
27
P
X
X X X X X
HSM
may
regenerated
These
core
one,
byte
and
BYTE
6 25
2
be
transferred
four
High-Speed
two
or
16,384(10)
is
the
smallest
is
made
bit.
24
in
memory
bytes
are
Memory
four
memory
byte
locations
addres-
up
of
3
22
2
21
X X X
to a memory
within
moved
side
HSM
eight
0
2
1.5
by
Examples:
215
0 0
0
0
0 0
0
1
The
first
of
HSM
quires
one
(1).
Within
bits,
BINARY ADDRESS
13
212
214
0
0
1
1
211
2
0 0 0 0 0 0 0
0
0 0 0
0
0
0
0
1
0
0
0 0 0
1 1
1
example
location
the
25.
adding
BINARY
0
2
3
2
24
the
70/25
are
allocated
10
9
8
2
2
0
1
1 0
0
1 1 1 1
0 0
0
1 1
1
27
2
shows
The
of
the
2n value
DECIMAL
instruction
for
each
1
st
ADDRESS
6
5
24
2
2
1 1
0 0
1
1 0 1
0
0 1
1 1
1 1 1 1
1
0 0 0 0
1
1
1 1
the
binary
conversion
of
EQUIVALENT
1
8
16
-
25
format
memory
3
0
22 21
2
2
1
0
0
1
0
1
1
1 1
1
1
I 0
0
o I 0
1 1
1
1
representation
to
decimal
all
bits
two
address.
2nd
ADDRESS
DECIMAL
EQUIVALENT
109
879
4.094
16.512
65,535
that
bytes,
25
reare
16
To
save
processing
ware
moves
whenever
or
serial
limits
defined
byte
units
of
memory,
first
word.
the
third
term
used
locations
several
70/25
boundaries
HSM
ADDRESSING
The
address
a
binary
dress
the
(65,536).
3
instructions
possible,
transfer
by a specific
are
locations
The
with
to
describe
0,
4,
instructions
(see
of
number.
highest
called
second
8,
etc.
8,
etc.
page
each
time,
returning
when
words.
0,
begins
Even
the
The
41).
byte
Sixteen
location
the
memory
and
data
to a byte
necessary
operation.
The
1,
2,
and
with
Word
initial
addresses
must
location
bits
are
of a four
in
first
3,
boundary
byte
begin
is
required
access
four
byte
after
to
stay
These
four
constitute
location
of
each
contained
at
even-word
expressed
plane
hard-
units
byte
within
four
bytes
the
4,
and
is
the
word;
as
to
ad-
system
in
An
address
ment
of
12
a
base
address
fifteen
The
Bl
most
or
General
B2
containing
B
FIELD
Assume
40,000(10)
is
divided
bits
contained
which
Registers.
significant
fields,
the
associated
0001
(2)
1000(2) -
1111(2) -
0000(2) -
that
General
.
into
is
four
designate
-
General
General
General-
No
base
two
parts:
in
the
pre-stored
bits
of
the
base
address.
Register
Register
Register
address
Register
(1) a displace-
instruction,
in
one
each
address,
General
1
8
15
One
and
(2)
of
the
the
Register
contains
3

147
When
an
is
added
the
two
address
example
the
is
added
register
resulting
of
This
technique
addresses
is a fixed
least
significant
for
base
locations
addresses.
This
addressing
larger
dresses
The
r-,--
r----
maximum
2,048
211
1
members
1.024
10
2
1 1 1 1
OP M
the
base
called
to
1,
in
makes
within
length
address
which
exceed
value
256
128
9
8
2
2
F(16)
the
actually
the
an
instructions.
of
bits
values,
require
concept
of
.
64 32
27
26 2
1 1 1 1 1
(16)
instruction
to
is
value
above,
displacement,
may
512
0001(2)
is
staticized
address.
effective
base
effective
it
unnecessary
used
address
address
The
address,
in
Each
12
bits.
However,
of
general
registers
it
is
13,
possible
14, 15,
is a necessary
the
Spectra
16-bit
70
lengths.
of a displacement
--
16
4 2
1
8
3
5
22 21
24
2
2°
1
1
4000(10)
the
displacement
absolute
execution.
in
to
carry
displacement
since
may
series
is
DECIMAL
VALUE
POWER
OF
BINARY
ADDRESS
sum
and
is
In
4000(10)
40000(10)
44000(10)
lengthy
the
be
used
to
access
or
16
feature
where
4095(10)'
-~
TWO
the
the
16
bit
ad-
128
256
512
1024
2048
4095
of
in
16
32
64
powers
hexadecimal
press
through F have
values
symbols
of
its
10
the
base,
basic
through
for
system
digits.
been
the
digital
any
value
requires
assigned
15
in
can
The
to
order
values
be
expressed.
sixteen
alphabetic
represent
to
of
the
symbols
letters
the
maintain
hexadecimal
The
to
ex-
decimal
single
A
system.
Each
symbol
expressed
fore,
two
sent a byte,
an
HSM
HEXADECIMAL
2
4
8
in
by
four
hexadecimal
and
address.
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
the
bits
four
hexadecimal
hexadecimal
in
the
binary
marks
are
BINARY
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
system
system.
required
marks
DECIMAL
I
I
I
can
10
11
12
13
14
15
can
There-
to
repre-
express
0
1
2
3
4
5
6
7
8
9
be
When
addressing
4095(10)'
a
displacement.
D1
or
value
B2
fields.
no
D2
fields
0000(2)
base
HEXADECIMAL
The
binary
is
not a convenient
hexadecimal
the
base
the
binary
The
upon
(0-9)
positional
sixteen,
decimal
the
number
to
represent
system,
numbering
representation
system
notation
locations
address
The
need
12-bit
becomes a direct
is
placed
NUMBERING
in
the
SYSTEM
although
notation
for
system,
is a convenient
of
is a numbering
ten.
It
uses
the
basic
digits.
that
indicates
between
be
associated
address
carried
address
corresponding
efficient
the
for
programmer.
which
method
HSM
addresses.
ten
single
By a system
multiplication
0000(10)
when
the
operates
to
express
system
symbols
and
with
in
the
the
B1
and
70/25,
The
based
on
of
by
Conversion
4
of
The
The
to
decimal
4 x
binary
its
decimal
1 x 2
Hexadecimal
number
100
+ 7 x
number
equivalence
5
+ 0 x 24 + 1 x 2
to
Decimal
472
represents:
10
+ 2 x 1 = (472)10
(101101)2
by:
3
+ 1 x 22 + 0 x
32 + 0 + 8 + 4 + 0
+ 1 x 2
+ 1 = (45)10
A
hexadecimal
value
by
by
the
appropriate
multiplying
number
the
value
is
converted
hexadecimal
of
1 Gn .
can
be
0
to a decimal
converted
21
characters

Examples:
1.
Convert
1 x
4096
2.
Convert
3 x
3 x 256
The
first
(I024h6
actual
Each
hexadecimal
four
bits.
binary
its
binary
3
16
2
16
768
example
which
machine
Therefore,
by
replacing
value.
(1024)16
+ 0 x
+
(3AFj16
+
10 x 16
+
10 x 16
+
has a decimal
to
Decimal
16
2
+ 2 x
16
1
+ 4 x
16
o + 32 + 4 = (4132)10
to
Decimal
1
+
15 x 16
+ 15 x 1
160
+
shows
(binary)
0001000000100100
address
character
hexadecimal
each
hexadecimal
0
15
the
hexadecimal
value
can
= (943)10
of
(4132)10.
is:
be
represented
is
character
0
address
converted
The
by
to
with
2.
3.
4.
5.
6.
An
effective
of
a
Base
address
___
specify
pute
an
The
decimal
exceed
Convert
binary:
a.
A4E8(16)
b.
E82C(16)
c.
3D71(16)
Convert
decimal:
a.
B5F9(16)
b.
F93D(16)
and!
which
effective
___
following
following
HSM
and a ___
values
or
base
address
address.
value
_
address
are
of a displacement
hexadecimal
hexadecimal
_
stored
fields
is
will
the
of
be
absolute
in
an
used
numbers
numbers
sum
.
The
instruction
to
com-
may
not
to
to
(0001000000100100)2 = 4096
The
second
dress
Exercise:
1.
A
a
the
3AF
has a decimal
byte
___
70/25
example
consists
bit,
and
HSM.
shows
is
of
the
that
value
__
___
+ 32 + 4 (4132)10
the
hexadecimal
of
943.
information
addressable
bits
unit
ad-
and
in
7.
8.
Convert
decimal:
a.
b.
c.
Convert
decimal:
a.
b.
following
1100011000001010(2)
0000101001001110(2)
0010110001100000(2)
following
55067(10)
7007(10)
binary
decimal
numbers
numbers
to
to
hexa-
hexa-
5

DATA
AND
INSTRUCTION
FORMAT
DATA
FORMATS
When
representing
character
(packed
UNPACKED FORMAT
A
byte
represent
format,
any
play
Some
the
hexadecimal
indicated
Char.
(unpacked
format).
in
the
one
for
characters
output
A
B
C
D
E
F
G
H C8
I
of
the
in
Hex.
Cl
C2
C3
C4
C5
C6
C7
C9 R
Char.
BLANK
.
(Period)
such
unpacked
alphabetic
example
that
as
more
representation
the
tables
ALPHABETIC
Char.
J
K
L
M
N
0
P
Q
SPECIAL
<
(
+
& 50
$
*
)
data, a byte
format),
format
or
numeric
is
required
are
to
appear
the
Printer
commonly
below.
Hex.
Char.
Dl
D2
S E2
D3
T
D4
U
D5
V
D6
W
D7
X E7 7 F7
y
D8
D9
Z E9 9 F9
CHARACTERS
Hex.
EO
4B
4C
4D
4E
5B
5C =
5D
may
store a single
or
two
numeric
uses
all
eight
character.
for
the
storage
on
any
type
or
Typewriter.
used
characters,
of
their
bytes
NUMERIC
Hex.
Char.
0
1
2
3
E3
E4 4
E5 5 F5
E6
6 F6
E8 8 F8
Char.
-
(Minus
/ Hyphen)
,
(Comma)
%
# 7B
@
t (Quote)
Space
Hex.
60
61
6B
6C
7C
7D
7E
40
digits
bits
of
are
Hex.
FO
Fl
F2
F3
F4
to
This
of
dis-
and
as
PACKED
In
digits
sign
The
packed
a
UNPACKED
PACKED
It
either
has
SIGN RECOGNITION
In
is
If
one
negative.
Mter a decimal
result
Thus,
data
L
(11 punch)
a
EDITED FORMAT
DATA
packed
except
in
the
following
and
byte
shown
should
be
packing
its
zone
decimal
recognized
(1)
All
(2)
Qriftherightmostbitisa(0}z
(1110)2'
the
sign
of
the
is
one
(1100)2
(1101)2
in
preparing
fields,
e.,
for a negative
zone
portion
FORMAT
data
for
four
example
packed
in
noted
and
arithmetic
as
one
has a low-order
remaining
of
for
for
the
in
the
format,
the
low-order
hexadecimal
or
numeric
positive
bits
arithmetic
the
positive
negative
user
least
of
one
rightmost
shows
format.
1
FO 1 F3
16
103
I
(as
in
the
unpacking a field
portions
operations
ifthe
(1111)2
bits
following:
source
may
follow
field
an
significant
(11012),
byte
stores
byte
bits.
the
Each
location
format.
1 F1 I
1 21 1
example
sign
bit
of
is
(0)
2'
operation
card
existing
overpunch
two
which
contains
same
field
represents
F6
1 F2 1 F1 I 80 I
OS
I
above)
the
rightmo
reversed.
the
sign
position
Le.,
(1)
2'
and
it
is
considered
the
sign
input
for
procedures,
of
the
position
generates
decimal
the
in
un-
that
when
st
byte
of a field
contains:
(1010)2'
at
least
of
the
numeric
minus
A
decimal
assumed
of
the
right
portion,
all
ones
However,
before
arithmetic
numeric
to
contain a sign
most
will
have
(11112),
the
decimal
it
may
be
operation.
byte.
the
used
field
in
All
four
numeric
as
in
unpacked
the
high-order
other
bytes,
high-order
field
an
operand
format
four
in
the
bits a value
must
be
packed
in a decimal
is
bits
zone
of
6
A
packed
format
A
field
sary
I -
numeric
with a single
in
edited
edit
symbols.
1
1 -
field
EDIT
form
is
01 01
0
may
instruction
unpacked
23
I
+
1
2
1
be
and
placed
(see
contains
48
3
in
page
neces-
4
edited
33).
1
-I

MACHINE
The
An
bytes.
The
The
struction
as a binary
divided
(Ll'
(M),
(R
1
tains a trunk
The
ment
which
with
INSTRUCTION FORMAT
70/25
instruction
first
byte
format
to
into
L2).
or
one
-R3).
third
and
(D)
and
contains
that
displacement.
instruction
may
of
each
of
the
the
next.
length
counter
two
length
In
still
or
more
The
second
and
device
fourth
the
number
the
3rd
format
contain
instruction
second
In
some
counters
others,
General
byte
designation.
bytes
of
base
byte
either
byte
instructions
(L).
it
is
Register
of a I/O
hold
the
the
address
4th
is
variable
two,
is
an
operation
varies
In
others , the
of
four
used
to
command
address
General
to
be
byte
in
length.
four,
or
code.
from
one
it
is
used
byte
bits
each
hold a mask
numbers
con-
displace-
Register
associated
six
in-
is
(R),
(B)
FOUR-BYTE
lop
1
op
Conditional
INSTRUCTIONS
81M41IG~IB241D2
81
R:IIG~I
Test
Set
B241
and
Unconditional
Under
P2
Register
D2
Mask
121
121
Branch
In a two-address
constitute
The
using
SIX-BYTE
the
machine
each
format
INSTRUCTIONS
Binary
Decimal
Decimal
Packing
Data
Logical
Logical
Data
Band D field
formats
Movement
instruction
are
Arithmetic
Arithmetic
Comparison
and
Operations
Comparison
Editing
the
of
and
the
shown
below:
Unpacking
(And,
the
fifth
second
type
Or,
and
sixth
address.
of
instructions
Excl.
Or)
bytes
IGN:
TWO-
True
T F
T F
These
instruction.
BYTE
and
False
1.
2. A numeric
Load
Multiple
Store
Multiple
bits
are
not
INSTRUCTIONS
Halt
Input/Output
Exercise
Data
Edited
be
in
packed
assumed
order
four
field
to
contain
bytes
format.
for
used
(Post
display
in
unpacked
an
of
each
(ignored)
Status)
purposes
(F)16
byte.
format
in
the
by
the
may
is
high
Input/
Output
7
T F
3.
When
packing
rightmost
portions
or
byte
has
reversed.
unpacking a field,
its
zone
and
numeric
the

INTRODUCTION
An
interrupt
the
detection
for
an
of
sensing
matic
mechanized
software
unnecessary
develops,
demands.
response
PROGRAMMING
All
instructions
(1)
the
State
of
operation.
transfer
State
the
original
facility
immediate
for
transfer
in
with
and
This
independently
Processing
(P2).
The
from
where
it
Processing
of
to
eliminate s program
provides
exceptional
program
exceptional
of
control
the
RCA
the
hardware
halt
the
system
STATES
are
executed
State
Processing
An
interrupt
the
Processing
remains
conditions,
conditions
70/25
computer
allows
of
his
(P1) ,
until
State.
an
automatic
response.
to
software
hardware.
interrupt
sensing
the
user
production
in
one
or
State
is
causes
State
instructed
means
and a method
The
function
and
the
has
Combining
makes
when
an
of
external
to
program
processing.
of
two
(2)
the
Interrupt
the
normal
the
computer
to
the
Interrupt
to
return
INTERRUPT
The
an
for
auto-
been
it
error
a
states:
mode
to
to
counter
instruction
tions
puter
(see
resets
returns
interruptable.
"PENDING"
State.
Interrupt
instruction.
to
the
lows
automatic
interrupt
process.
TYPES
system
instruction
is
may
remains
page
the
Control
occurs
the
Process
address
the
point
OF
INTERRUPT
is
now
in
the
is
staticized
updated
to
be
39)
P2
be
executed.
executed
in
this
is
executed.
counter
to
Any
until
the
to
contain
state
Pl.
interrupt
computer
only
Therefore,
after
interrupt,
of
the
instruction
where
linkage
permits
considerations
Interrupt
the
the
All
in
the
P2
until a STPP2
The
to
its
The
Interrupt
after
the
when
that
interrupt
the
when
State.
contents
address
thirty-one
state,
STPP2
original
attempted
returns
to
termination
the
system
the
P1
immediately
took
user
programming
Each
of
of
instruc-
and
the
instruction
instruction
value,
State
will
the
Process
counter
place.
to
disregard
time
the
the
next
com-
and
is
not
of
returns
holds
fol-
This
his
P2
be
an
PROCESSING
During
the
address
stored
and
forty-one
121512141213121212111210129128127126125124123122121120
Each
time
the
contents
the
address
instructions
computer
the
in
the
BYTE
an
remains
STATE
execution
of
the
P1
counter
(29)16'
(40)10
instruction
of
the
P1
of
the
may
be
of
next
PI
counter
next
executed
in
this
instructions
instruction
(reserved
COUNTER
is
staticized
is
instruction.
in
state
in
to
be
HSM
BYTE
(41)10
in
updated
All
the
P1
until
the
executed
forty
the
P1
to
thirty-one
state.
an
interrupt
occurs.
INTERRUPT
When
interrupt
to
the
counter
five
STATE
an
exceptional
initiated,
instruction
(reserved
(2D)16)'
BYTE
(44)10
condition
the
whose
HSM
P2
hardware
address
forty-four
COUNTER
is
detected,
transfers
is
(2C)16
stored
in
and
P1
state
(28)16
state
contain
The
and
control
the
P2
forty-
is
an
I
There
are
Processing
1.
I/O
Device
2.
Operation
3.
Arithmetic
4.
Elapsed
1/0
INTERRUPT
An
interrupt
Input/Output
indicates
1.
The
I/O
fully
Indicator
(see
page
2.
The
channel
tion
is
command
event,
set
to
The
purpose
notify
system
able.
With
four
State:
(Manual
Code
Overflow
Timer
occurs
Command.
one
of
two
instruction
(ERROR).
bit
53).
and
now
free,
(NORMAL
the
26
(1)2'
(see
of
software
this
conditions
Trap
Overflow
after
possible
was
In
in
the
Standard
device
and
bit
of
the
page
normal
that
knowledge,
that
can
or
Termination)
or
Divide
the
A
Exception
termination
termination
terminating
not
completed
this
case,
the
Device
that
executed
ready
to
receive
TERMINATION).
Standard
Device
53).
termination
an
the
I/O
interrupt
channel
software
interrupt
of
interrupt
conditions:
success-
Secondary
Byte
the
instruc-
the
Byte
is
can
each
is
(1) 2
next
In
this
is
avail-
the
is
to
use
9

efficiently
taining
A
communications
control
generates
ruption
the
Standard
Prior
the
eight
by
the
an
is
distinguished
to
entering
matically:
1.
Stores
The
present
in
the
20 - 21
forty-three
overlap
I/O
operator
I/O
Device
the
state
Channels.
device
Interrupt.
Byte
the
ofthe
value
ofthe
bits
(2Bh6'
capabilities
request,
at
the
console
Console
by
the
fact
is
set
P2
state,
Condition
Condition
of
the
reserved
of a system
or a request
typewriter
that
to
(1)2'
the
computer
Code
Code
request
the
Indicator,
is
HSM
con-
for
also
inter-
27
bit
auto-
stored
location
of
OPERATION CODE
If
an
instruction
code
is
not
one
of
interrupt
Operation
Prior
is
Code
to
entering
initiated.
matically:
1.
2.
Stores
in
Stores
interrupt
two
the
20 - 21
(2A)16'
the
the
state
illegal
in
TRAP
is
staticized
the
Trap.
the
bits
the
thirty-one
This
P2
state,
of
the
Condition
oflocation
operation
reserved
in
which
legitimate
interrupt
the
forty-three
code
HSM
the
Operation
codes,
is
called
computer
Code
Indicator
that
caused
location
auto-
(2Bh
forty-
an
an
6'
the
The
2.
Stores
Number)
reserved
Device
the
3.
Stores
rupting
forty-six
See
page
Byte.
The
P2
struction
occurs.
a
Branch
(00) 2
indicates
I/O
device.
stored
routine
For
example,
one
on
been
depressed,
contain:
~~
Condition
Trunk
127
~~
Number
53
counter
of a routine
This
On
in a reserved
to
identify
Trunk
the
identification
of
HSM
Number
Number
BYTE
126
125124123\
Trunk
the
Standard
device
(2Eh6'
for a desc
contains
routine
Condition
that
The
Trunk
the
if
the
three,
then
Code
Indicator
the
interrupting
location
is
stored
is
(47)10
in
the
ription
to
tests
interrupt
and
area
device
Console
and
HSM
is
(Trunk
forty-seven
in
the
stored
in
22\ 21
Device
Number
Device
Byte
reserved
of
the
the
address
be
executed
the
Condition
instruction).
had
been
Device
of
HSM,
that
caused
Typewriter
the
Interrupt
location
then
set
and
device
(2Fh6'
20 - 23 bits,
the
24 -27
120
for
the
HSM
Standard
of
the
when
interrupt
Code
A
setting
caused
Number
have
allowing
the
interrupt.
is
button
forty-seven
to
(00)
Device
in
The
and
bits.
Inter-
location
Device
first
(with
by
been
Device
had
would
2'
the
in-
of
an
the
BYTE
The
two
dicate
3.
high-order
the
length
00
01
or
11
Sets
the
routine
(01)2
indicates
an
illegal
viously
the
situation,
be
an
error,
latter
case,
struction
For
example,
for
Convert
on
the
could
10
Condition
tests
staticized
that
70/25.
be
bits
of
the
two-byte
four-byte
six-byte
the
that
operation
the
illegal
or
an
the
interrupt
is
not
the
Decimal
However,
simulated
state.
ARITHMETIC OVERFLOW
A
carry
out
of
the
high-order
operand
(FAh6
causes
(FD) 16
rupt
during
or a Subtract
interrupt.
operation
occ
urs
.
the
If
are
the
(42)10
of
the
instruction.
Code
to
Condition
the
interrupt
code
in
the
PI
operation
intentional
part
of
70/45
would
by
instructions
AND
DIVIDE EXCEPTION
execution
Decimal
operands
not
properly
Operation
instruction
instruction
instruction
(01)2'
The
Code. A setting
was
in
the
instruction
state.
Depending
could
interrupt.
could
simulate
the
70/25
order
operation
cause
the
decimal
code
an
position
of
an
Add
(FBh6
of a Divide
edited,
Code
in-
interrupt
caused
by
pre-
on
actually
In
the
an
in-
code.
(4E)16
interrupt
conversion
in
the
P2
of
the
first
Decimal
instruction
Decimal
an
inter-
of
Trunk
3
Device
1
the
ferring
10
Hardware
20 - 21
(2Bh6'
and
to
stores
bits
resets
the
the
of
the
Interrupt
state
reserved
code
State.
of
to
the
Condition
location
(10)2'
forty-three
before
Code
trans-
in

ELAPSED
TIMER
INTERRUPT
Exercise:
General
clock.
power)
added
register
intervals
value
Before
of
reserved
reset
INHIBITING
All
be
(31)16
selected
the
tion.
eight
and
A
and
channels
If
channel
addressed
Three
forty-eight
Timer,
CHANNEL
A
mask
plex
arithmetic
INTERRUPT PRIORITIES
the
to
pre-stored
transfer
the
Condition
to
interrupts
inhibited.
allows
eight
The
I/O
a (0)2
mask
seven
an
interrupt
bit
interrupt,
Register
Every
power
the
contents
overflows,
between
location
(11)2'
INTERRUPT
the
I/O
channels.
rightmost
bit
positions,
channels,
bit
inhibits
of
10010110
to
interrupt,
zero,
remains
to
that
positions
(30)
Arithmetic
interrupts.
of
101
in
overflow
Op
Code
16-2/3
except
three,
on
16
I/O
Elapsed
Overflow
Divide
Zero
serves
milliseconds
supply
generates a (1) 2 bit
of
Register
interrupt
interrupts
in
the
register
to
the
P2
state,
Code
is
stored
forty-three
the
Operation
Reserved
user
to
HSM
inhibit
The
bit
positions
(20-27),
0-7.
A (1)2
it.
LOCATION
allows
and
five,
an
I/O
channel
busy
until a Post
channel,
is
(22_2°)
allow
the
user
Overflow,
the
22_20 allows
but
inhibits
or
divide
Trap -immediate
Timer
and
Exception
as
takes
is
controlled
(see
the
in
the
(2Bh6'
location
interrupt
user
places a mask
of
the
correspond
bit
permits
49 (31)16
channels
inhibits
and
six.
Status
executed
in
reserved
to
inhibit
and
21=Overflow
22=Timer
0co
2
Timer
interrupt
exception.
1
2
3
an
elapsed
(using
Zero.
place.
page
current
20 - 21bits
and
Code
Trap
forty-nine
reserved
one,
two,
interrupt
is
inhibited,
instruction,
(see
page
the
MULTIPLEX
Multiplex
and
caused
time
60
cycle
that
When
the
The
time
by
the
13).
setting
the
code
may
on
all
into
loca-
to
the
interrupt
four
from
the
53).
location
Elapsed
Channel
Multi-
by
is
of
or
T F
T F
T F
T F
T F
T F
T F
T F
T F
T F
T F
T F
T F
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Only
fifteen
structions
Interrupt
The
main
Processing
The
Processing
ruptible.
The
Interrupt
The
Condition
changing
The
Condition
prior
to
The
two
in
the
reserved
The
Processing
counter
next
instruction.
The
PI
interrupt.
The
computer
until
another
The
operation
Operation
The
Standard
an
Operation
Interrupt
only
interrupt
Describe
Describe
Trap.
Write
the
possible
be
stored?
Describe
memory
interrupt
of
the
can
State.
program
State.
State
Code
states.
Code
going
into
program
to
indicate
counter
remains
interrupt
Code
Device
Code
from
that
the
use
two
uses
masks
interrupts.
what
when
each
takes
place.
thirty-one
be
executed
is
State
is
not
is
is
always
the
P2
counters
area
of
State
the
is
destroyed
occurs.
code
is
Trap.
Byte
Trap.
any
r/o
can
be
of
HSM
of
the
necessary
Where
is
stored
of
the
70/25
in
executed
is
not
interruptable.
stored
prior
set
state.
are
stored
memory.
uses
only
address
of
by
in
the
P2
stored
is
stored
device
inhibited.
location
Operation
to
inhibit
must
in
reserved
four
types
inthe
in
the
inter-
to
one
the
the
state
on
is
the
49.
Code
all
they
to
00
an
on
of
11

SUMMARY
OF
70/25
INTERRUPT
LOGIC
Instruction
Store:
1.
CC
2.
Op
in
Code
Store
in
HSM
HSM
in
CC
43
Op
43
HSM
Arith.
Code
42
Overflow
Trap
Interrupt
Indicator
Set?
Yes
I/O
Op
Code
Arithmetic
Overflow
Elapsed
or
Trap?
Neither
or
Timer?
No
I/O
Store:
1.
2.
3.
Instruction
Interrupt
Inhibi
CC
in
TK
and
Stand.
ted
Mask?
HSM 49
No
HSM
43
DV#
in HSM
DV.
Byte
Set
CC
to
(00)2
Interrupt
"Pending!!
By
47
in
HSM
Yes
48
Return
Transfer
to
Interrupt
Identify
(CC
Setting)
Process
Accordingly
STP2
Register
to
Processing
State
Interrupt
and
12
r
HARDWARE
PROGRAMMING
1
State

The
least
significant
first
General
clock.
every
bit
register
(see
time
tion
A (1) 2
as
If
is
of
follows:
1 ADD
50 ADDS
3000
180000
the
The
16-2/3
added
overflow
page
interval
the
value
is
added
50
CYCLE
EVERY
EVERY
ADDS
EVERY
ADDS
EVERY
Timer
70/25
to
11).
(16,777,215>10'
the
Timer
place
power,
The
meaningful
16-2/3
1
1
contains
approximately
or
77
number
time
MILLISECONDS
SECOND
30
SECONDS
MINUTE
30
MINUTES
1 HOUR
Register,
power
milliseconds
the
contents
develops,
The
programmer
between
stored
to
the
POWER
20
MILLISECONDS
SECOND
MINUTE
HOUR
is
set
the
first
all
93
hours
later
of
adds
intervals
60
CYC
24
bits
of
may
serve
supply
(60
of
Register
an
these
interrupts
in
the
register.
low
order
1 ADD
60 ADDS
3600
ADDS
216000
ADDS
to a value
add
causes
zeros,
hours
later,
using
required
are
indicated
LE
POWER
Register
as
an
generates
cycle
interrupt
may
bit
of
60
CYCLE
EVERY
16-2/3
EVERY
SECOND
EVERY
MINUTE
EVERY
HOUR
of
overflow
using
60
cycle
to
clock
1 ADD
60 ADDS
1800
ADDS
3600
ADDS
108,000
216,000
ELAPSED
Zero,
the
elapsed
power).
Zero.
by
the
POWER
all
overflow.
power.
below:
a (1)2
When
is
initiated
control
the
selec-
register
MILLISECONDS
one
will
50
cycle
off
more
ADDS
ADDS
time
bit
This
the
bits
take
If
TIME
The
CLOCK
overflow
16,777,21610.
an
interrupt
the
number
overflow
stored
It
should
reduced
the
initial
fore
the
no
time
Regi
ster
purposes.
(the
22
addition
Exercise:
If
we
want
what
value
value
Let
every
of
adds
value,
we
in
the
register.
16,777,216(10)
3,600(10)
16,773,616(10)
be
remembered
to
zero
at
the
value
is
added
computer
loss
Zero
Even
bit
of
of
(1) 2
returns
results.
may
though
reserved
bits
to
interrupt
should
be
of
the
us
assume
minute.
executed
can
determine
point
to
not
be
we
By
in a minute,
that
the
of
overflow.
the
register
to
the
used
interrupt
HSM
location
the
register
after 5 minutes
stored
in
register
24
bit
wish
to
subtracting
the
amount
to
FFF1EF(16)
timer
contents
As
contents
Processing
for
general
has
been
48
is
contents
and
continues.
30
zero?
Timer
generate
360010'
from
to
long
State,
storage
inhibited
(0)2),
seconds,
is
the
be
is
as
be-
the
13