IBM 2030 Manual

Field Engineering
Manual
of Instruction
Processing Unit
System/36D Model 3D

PREFACE
This manual contains information
about the IBM 2030 Processing unit.
A companion manual on input/output
control should be obtained for
information pertaining to the
attachment of I/O devices to the
IBM System/360 Model 30. The
companion manual is the IBM 2030
I/O Control Field Engineering
Manual of Instruction, Form
225-3362.
Minor Revision, August 1965
This edition, 225-3360, is identical in
content to the previous edition, Z25-336Q.
The
IBM Confidential classification has
been removed and the form number has been
changed to allow free access to the manual.
Address comments concerning the content of this publication to mM Product Publications, Endicott, New York 13764.
© 1965 by International Business Machines Corporation

CONTENTS
SECTION
1. COMPREHENSIVE INTRODUCTION
System Configurations ...••.••.......
System Concepts ............•......••
Numbering Systems ....•.•.....•••••..
Ari thmetic Principles ........•..•...
Data Flow ..•...•••....•....•..•.•.•.
Basic Programming .......•.••..•.•.•.
Instruction Sequencing and Branching
The System/360 and Interrupts .••.••.
Storage Protection •••.•.•...•...•.•.
SECTION 2. FUNCTIONAL UNITS ...•.•...
SLT Circuitry .•....••....•••....•...
Remembering Devices .••.••.•..••.••..
Combined Components ..•••...••...•••.
Central Processing Unit (CPU) Clock •.
Arithmetic Logical Unit (ALU) .....•.
Registers ......••..•.••....••......•
Core Storage ..••...•..•...•••.......
Memory Control ..................... .
SECTION 3. THEORY OF OPERATION •...•.
Concepts of Capacitor
Read Only Storage ..•••.....•..•..•
Micro Programming Introduction ....••
Micro Program Examples •..........•••
Control Field Mnemonics ...•...••..•.
Parity Bits •..•....•....•••...•..••.
ROS Addressing ...............••...•.
ROAR Con tro 1s ......•...........•..••
ROS ·T imings •.....•.••..••.•.•...•...
Physical Description ....•.•...•...•.
Machine Check Handling ....•.•.•.....
Forced Micro Program Entries ..•.....
Overall Timing Relationships .....•..
SECTION 4. POWER SUPPLy ............ .
SECTION 5. SPECIAL FEATURES ..•.•..•.
1401, 1440, and 1460
Compatibility Features ...•......•.
Interval Timer ..........•....•....•.
APPENDIX 1
APPENDIX 2
••••••••••••••••••••••••••
Upper Indicator Panel .............. .
Lower Indicator Panel ..........••...
Operator Panel .....................•
Control Keys •......•••......••...•..
Mode Control Panel ................. .
Meter Panel .••..•.•...••••..........
1-1
1-1
1-5
1-21
1-25
1-31
1-35
1-43
1-49
1-69
2-1
2-1
2-3
2-4
2-5
2-10
2-22
2-23
2-62
3-1
3-1
3-15
3-23
3-44
3-51
3-53
3-60
3-63
3-66
3-7l
3-76
3-80
4-1
5-1
5-1
5-48
6-2
6-5
6-5
6-7
6-9
6-11
6-15
6-17
ANSWERS TO REVIEW QUESTIONS ••......• 6-19
INDEX •...•.....•...•...•.......••.•• 7-1

SYSTEM CONFIGURATIONS
• Single system concept.
• Different models provide a variety
of processing speeds and storage
sizes.
• Broad range of input/output devices.
• Uses an 8-bit coding structure to
represent data.
• program compatibility throughout
system models.
Behind the decision to design the IBM
System/360 - a single system which
encompasses all areas of data processing
lies the awareness that apparently unre-
Figure 1-1. IBM System/360, Model 30
SECTION 1. COMPREHENSIVE INTRODUCTION
lated applications have more similari-
ties than differences. For example,
because of teleprocessing and other
factors, scientific applications require
high-speed input/output similar to that
required by commercial applications. In
addition to this versatility, the
System/360, because of its modularity,
adaptability and compatibility, can
handle the many kinds of growth that
normally occur in computer
installations.
Modularity in the System/360 is
achieved through the availability of
seven models. A typical Model 30 system
is shown in Figure 1-1. In addition to
a choice of processing speed through'
model selection, each model offers a
choice of storage capacities.
1-1

AS problems and workloads grow or
change, the System/360 can easily be
expanded o.r changed to handle additional
or different operations. Storage can be
added and input/output and processing
speeds increased -- in small increments,
as needed. This adaptability makes
provision for the inclusion, either
initially or subsequently, of a broad
range of input/output devices.
Versatile performance characteristics
permit handling of data in virtually any
desired character representation.
Instead of the usual six-bit character,
the System/360 employs a new eight-bit
coding structure to represent data. An
8-bit unit of data is called a byte.
This 8-bit coding structure allows 256
possible combinations for letters,
digits and symbols, providing greate.r
versatility in both binary and decimal
operations. It also means that
System/360 can accept a character code
of fewer bits, such as a telegraph code.
More important than the modularity
and adaptability of the System/360 is
its compatibility. A program written
for one configuration will run on any
other, if there is enough memory capaci-
ty and input/output equipment, and if
the program is not geared to the operat-
ing speed of any particular unit. Sub-
ject to these constraints, a program
written for a smaller System/360 will
run without modification on a larger
one. While this -upward- compatibility
is certainly an advantage, -downward-
compatibility can be even more valuable;
for example, a small user can utilize
1-2
programs written for larger systems.
This places a total library of programs
at all users' disposal.
Compatibility further allows a
System/360to be tailored to fit either
centralization or decentralization.
That is, a company'sinstallation can be
either a large central processor or a
number
of smaller processors. Shifts
between the extremes are possible within
the same system.
Traditionally there have been
constraints on computer versatility, so
that one processor has lent itself to
scientific and engineering application,
another to commercial data processing
applications, another to process
control, and still another to communi-
cations.
The System/360 provides a versatile
set of instructions that permit operat-
ing quickly and efficiently regardless
of the system application.
MODELS AND SPEEDS
- Different processor models provide a
variety of processing speeds and
core storage siz.es.
-The 2030 is the processor for the
System/360, Model 30 (Figure 1-2).
- The 2030 is available in four core
storage sizes, represented as
System/360, Models C30, D30, E30,
and F30.

Figure 1-2. IBM 2030 Processing Unit
To fit the widely varied cost and volume
needs of all computer users, the IBM
System/360 is available in many differ-
ent models. For instance, to fit the
needs of the user who needs a minimal
number of answers per month, a Model 30
is available at a minimal cost. For the
user who needs a greater number of
answers per month, a Model 70 is availa-
ble that will give approximately 50
times as many answers per month as a
Model
30. The answers will be the sallie;
only the number of answers in a given
period of time will be different. There
are two basic differences between
models: core storage capacity and inter~
nal processing speeds. Figure 1-3 shows
the core storage capacities for the
different System/360 models. Internal
processing speed is largely dependent on
the speed of the core storage unit and
the amount of data involved on each core
storage access. Core storage speed in
the System/360 varies from 2 micro-
seconds per single byte access on the
Model 30's to 1 microsecond per eight-
byte access on tpe Model 70's (Figure
1-4) •
1-3

Storage Capacity
in Bytes
524,288
262,144
131,072
65,536
32,768
16,384
8,192
System/360 Models
Figure 1-3. System/360 Storage
Sizes
Processor System/360 Models Bytes/ Memory Speed
Access
2030 C30, D30, E30,
F30 1 2.0 microseconds
2040
D4O, E40, F40, G40, H40
2
2.5 microseconds
2050 F50, G50,
H50
4
2.0 microseconds
2060 G60, H60, 160
8 .
2.0 microseconds
2062 H62,
162
8 1
.0 microseconds
2070 H70,
170
8 1
.0 mi croseconds
Figure 1-4. System/360 Storage
Access and Speed
1-4
GENERAL DATA FLOW
• The processing unit controls the
system.
•
•
•
Information enters the system from
an input device.
The information is manipulated by
the processing unit to develop the
required answers.
The a,nswers are sent to an output
device to be stored.
In the System/360, Model 30, the 2030
processing unit provides all system
control. The processing unit is given
instructions by a programmer. These
instructions are interpreted and
executed by the processing unit. Execu-
tion of an instruction might involve
adding two numbers together, or it might
involve causing a printer to print a
check. Regardless of the instruction,
the interpretation and control lies in
the 2030 processing unit.
General data flow is divided into
three operations (Figure 1-5). First,
information comes into the processing
unit via some input device. This infor-
mation is then used along with input
information from other devices and con-
stant information contained in main
storage to develop the required result
or output. This output is then sent to
an output device where the resultant
information is stored. The information
storage may be a printed report, punched
cards, or magnetized spots on a .reel of
magnetic tape.

2030 Processing Unit
Main
Storage
Input/
r--..-( Output
Channel
Control
Unit
Random
Access
Device
Control
Unit
Random
Access
Device
Data and Control Information -4.----~
Arithmeti c,
Control, and
Register
Systems
Figure 1-5. General Data Flow
SYSTEM CONCEPTS
• Programming Systems support of the
IBM System/360 is called Operating
System/360.
Control
Unit
• The Operating System/360 supports
the Computing System/360. Together
they make up the IBM System/360.
The introduction of the IBM Systeml360
marks the achievement of a truly all-
purpose computer that can solve any type
of data-handling problem with greater
speed and efficiency than ever before.
This opens up greatly increased computer
potential in every area.
In order to realize this potential,
it was apparent to the designers that
the programming support needed to be as
powerful and as extensive as the
Control Unit
Printer
computer. In fact, programming support
should make the IBM System/360 an even
mO.re powerful system.
This lead to the concept of the Com-
puting System/360 (hardware) being sup-
ported by the Operating System/360
(programming), together making up the
System/360.
r--------------------------,
I I
, I
'r------------------, ,
I IComputing System/3601 I
I l
____________________ J I
I I
, Operating System/360 IL __________________________ J
IBM System/360
This means that a customer is getting
a system that is powerful and flexible,
1-5

yet, due to extensive programming sup-
port, he can easily apply his problem to
the System. For one thing, he can write
problem solving programs without the
necessity of translating them into a
language understandable by the machine.
Once written, the operation of his pro-
gram is controlled or supervised by
Cperating System/360, relieving the
operator of many tasks and increasing
the utilization of the Computing
System/360.
OPERATING SYSTEM/360 CONCEPTS
• Control programs allowing monitored
operation of a system have been
proven by experience to produce
optimum computer utilization.
• Operating System/360 includes both
control programs, and IBM and user-
written processing programs.
• Basic programming Support programs
will be provided for System/360
systems with 8R bytes of storage.
As stated previously, IBM's single
system approach with the System/360
recognizes that computing systems and
programming systems should be integrated
and not developed independently.
Experience in the past decade has proved
that the optimum method of producing
this result is with monitored operation.
Early monitors were designed to mini-
mize human intervention. The new and
sophisticated control techniques includ-
ed in programming systems with the
System/36 0 extend its capabilities so
that the monitor and control functions
make up what is called an operating
system.
The basic purpose of Operating
System/360 is to permit the user to
solve problems and process information
effectively. Included in Operating
System/360 are both processing and con-
trol programs. Processing programs
include all application-oriented pro-
grams, including both IBM and user-
written.
For systems having 16K bytes of main
storage, basic control program functions
will be supplied with magnetic tapes or
direct access devices. Additional
1-6
capability can be utilized as more main
storage is added.
For systems having 8K bytes of main
storage, programming systems is supply-
ing basic programming support programs,
which perform many of the functions of
operating systems, including control
functions.
Control Programs
• Control programs perform functions
such as control of administrative
operations, job flow control,
Input/Output control, and program
execution control.
A basic key to achievement of high oper-
ating efficiency in a computing or data
processing installation is a good con-
trol procedure. This procedure must
include many functions: administrative
control of job schedules, workflow, and
computer usage records; cqntrol over
data and program libraries; control over
computer operations; and control over
the flow of programs and data within the
computing system during Job rUns.
The control programs for the IBM
System/360 set up a comprehensive con-
trol framework to assist the user in
satisfying the above objectives. The
control programs operate at various
levels of concept. For example:
1. Operations control of installation
and administration and workflOW,
including instructions from and to
the computer operator, administra-
tive records, logs of system opera-
tion, and control over library pro-
grams.
2. Job flow control, including I/O
transition between jobs and job
segments, unit assignments, initial
loading and initialization when the
computer is first turned on, control
between jobs, and control over the
type of operation mode, ranging from
simple stacked jobs through telepro-
cessing systems performing concur-
rent ope.rations.
3. Input/Output control, including
physical and logical control over
I/O records, files and units: buffer
control; teleprocessing terminal and
message handling; random access I/O