IBM 5150 Use and care manual

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Personal Computer
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Hardware Reference
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Library
Technical
Reference

Revised Edition (April 1984)
The foUowing paragraph does not apply to the United Kingdom or any country where such
provisions are inconsistent with local
law: International Business Machines Corporation
provides this manual
"as is," without warranty of any kind, either expressed or implied,
including,
but not limited to the particular purpose. IBM may make improvements and/or
changes in the product(s) and/or the program(s) described in this manual at any time.
This product could include technical inaccuracies or typographical errors. Changes are
made periodically to the information herein; these changes
will be incorporated in new
editions of the publication.
It is possible that this material may contain reference to, or information about, IBM
products (machines or programs), programming, or services that are not announced in
your country. Such references or information must not be construed
to mean that IBM
intends to announce such IBM products, programming, or services in your country.
Products are not stocked
at the address below. Requests for copies of this product and for
technical information about the system should be made to your authorized IBM Personal
Computer dealer.
The
foUowing paragraph applies only to the United States and Puerto Rico: A Reader's
Comment Form
is provided at the back of this publication. If the form has been removed,
address comments to: IBM Corp., Personal Computer, P.O. Box 1328-C, Boca Raton,
Florida 33432. IBM may use or distribute any of the information you supply in any way it
believes appropriate without incurring any obligations whatever.
© Copyright International Business Machines Corporation 1981, 1982, 1983, 1984

Federal Communications Commission
Radio Frequency Interference Statement
Warning: The equipment described herein has been certified
to comply with the limits for a Class B computing device,
pursuant to Subpart J
of Part 15 of the FCC rules. Only
peripherals (computer input/output devices, terminals
printers, etc.) certified to comply with the Class B limits may
be
attachedto the computer. Operation with non-certified
peripherals is likely to result in interference to radio and TV
reception.
If peripherals not offered by IBM are used with the
equipment, it is suggested to use shielded grounded cables
with in-line filters if necessary.
CAUTION
The product described herein
is equipped with a grounded
plug for the user's safety.
It is to be used in conjunction with
a properly grounded receptacle to avoid electrical shock.
iii

iv

Preface
r""'\. This publication describes the various units of the IBM Personal
Computer; and the interaction
of each.
The information in this publication
is for reference, and is
intended for hardware and program designers, programmers,
engineers, and anyone else with a knowledge of electronics
and/ or programming who needs to understand the design and
operation
of the IBM Personal Computer.
This publication consists of two parts: a system manual and an
options and adapters manual.
The system manual
is divided into the followirig sections:
Section 1, "System Board," discusses the component layout,
circuitry, and function
of the system board.
Section 2, "Coprocessor," describes the Intel 8087
coprocessor and provides programming and hardware
interface information.
Section 3,
"Power Supply," provides electrical input/output
specifications as well as theory of operation for the IBM
Personal Computer power supply.
Section 4, "Keyboard," discusses the hardware make up,
function, and layout
of the IBM Personal Computer keyboard.
Section 5, "System BIOS," describes the basic
input/output
system and its use. This section also contains the software
interrupt listing, a
BIOS memory map, descriptions of vectors
with special meanings,
and a set of low memory maps. In
addition, keyboard encoding and usage is discussed.
Section 6, "Instruction Set," provides a quick reference for the
8088 assembly instruction set.
v

Section 7, "Characters, Keystrokes, and Colors," supplies the
decimal and hexadecimal values for characters and text
attributes.
Section 8, "Communications," describes communications
hardware and discusses communications interface standards
and the sequence
of events to establish communications.
A glossary, bibliography, and index are also provided.
The options and adapters manual provides information, logic
diagrams, and specifications pertaining to the options and
adapters available for the IBM Personal Computer family
of
products. The manual is modular in format, with each module
providing information about a specific option
or adapter.
Modules having a large amount
of text contain individual indexes.
The modules are grouped by type of device into the following
categories:
• Expansion Unit
• Displays
• Printers
• Storage Devices
• Memory Expansion
• Adapters
• Miscellaneous
• Cables and Connectors
Full page length hard tabs with the above category descriptions,
separate the groups
of modules.
The
term" Technical Reference manual" in the option and adapter r"'-.
manual, refers to the IBM Personal Computer Technical Reference
system manual.
vi

The term "Guide to Operations manual" in the option and adapter
manual, refers to the IBM Personal Computer Guide
to Operations
manual.
vii

Prerequisite Publications
• IBM Personal Computer Guide
to Operations
Suggested Reading
• BASIC for the IBM Personal Computer
• Disk Operating System (DOS), Version 1.1
• Disk Operating System (DOS), Version 2.1
• IBM Personal Computer Hardware Maintenance and Service
•
MACRO Assembler for the IBM Personal Computer
viii

Contents
SECTION 1. SYSTEM BOARD ..•.••••...........•• 1-1
Description .................................. 1-3
Microprocessor
............................... 1-3
Data Flow Diagrams ........................... 1-5
System Memory Map
.......................... 1-8
System Timers
.............................. 1-11
System Interrupts
............................ 1-11
ROM
...................................... 1-13
RAM
...................................... 1-13
DMA ..................................... 1-13
I/O Channel ................................ 1-14
System Board Diagram
........................ 1-16
I/O Channel Diagram ......................... 1-18
I/O Channel Description ...................... 1-20
I/O Address Map ............................ 1-24
Other Circuits
............................... 1-25
Speaker Circuit
.......................... 1-25
Cassette Interface
........................ 1-27
Cassette Circuit Block Diagrams
............ 1-28
8255A
I/O Bit Map ...................... 1-31
System-Board Switch Settings
.............. 1-33
Specifications
............................... 1-34
Card Specifications
....................... 1-34
Logic Diagrams
.............................. 1-36
SECTION 2. COPROCESSOR ..................... 2-1
Description .................................. 2-3
Programming Interface
......................... 2-3
Hardware Interface
............................ 2-4
SECTION 3. POWER SUPPLY ..................... 3-1
Description .................................. 3-3
~ Input Requirements ........................... 3-4
Outputs
..................................... 3-4
Vdc Output
.............................. 3-4
Vac Output
.............................. 3-5
Overvoltage/Overcurrent Protection
.............. 3-5
ix

Primary (Input) ........................... 3-5
Secondary (Output)
....................... 3-5
Power Good Signal
............................ 3-6
Power Supply Connectors and Pin Assignments
...... 3-6
SECTION 4. KEYBOARD
......................... 4-1
Description
.................................. 4-3
Block Diagram
............................... 4-4
Keyboard Diagrams
........................... 4-5
Connector Specifications
...................... 4-12
Keyboard Logic Diagram
...................... 4-13
SECTION 5. SYSTEM BIOS
........•.•.•.......•.. 5-1
System BIOS Usage
........................... 5-3
Keyboard Encoding and Usage
.................. 5-14
BIOS Cassette Logic
.......................... 5-25
System BIOS Listing
.......................... 5-29
Quick Reference
......................... 5-29
SECTION 6. INSTRUCTION
SET ................... 6-1
8088 Register Model
.......................... 6-3
Operand Summary
............................ 6-4
Second Instruction Byte Summary
................ 6-4
Memory Segmentation Model
.................... 6-5
Use of Segment Override
....................... 6-5
Data Transfer
................................ 6-6
Arithmetic
................... . . . . . . . . . . . . . . .. 6-8
Logic
...................................... 6-10
String Manipulation
.......................... 6-11
Control Transfer
............................. 6-12
8088 Conditional Transfer Operations
............ 6-15
Processor Control
............................ 6-16
8087 Extensions
to the 8088 Instruction Set ....... 6-17
Data Transfer
............................... 6-17
Comparison
................................ 6-19
Arithmetic
.................................. 6-19
Transcendental
.............................. 6-21
Constants
.................................. 6-21
Processor Control
............................ 6-22
8088 Instruction Set Matrix
.................... 6-25
Instruction Set Index
................ . . . . . . . . .. 6-27
x

SECTION 7. CHARACTERS, KEYSTROKES, AND
COLORS
...................................... 7-1
SECTION 8. COMMUNICATIONS ................. 8-1
Communications .............................. 8-3
~ Establishing a Communications Link .............. 8-5
Establishing Link
on Nonswitched Point-to-Point Line 8-6
Establishing Link on Nonswitched Multipoint Line
... 8-8
Establishing Link
on Switched Point-to-Point Line .. 8-10
Glossary •.•..•.•.....•••.•..•..•....•..•.•• Glossary-1
Bibliography .............................. Bibliography-1
Index ........................................ Index-l
xi

xii

INDEXTAB LISTING
Section 1. System Board ............................... .
Section
2. Coprocessor ................................ .
Section 3. Power
Supply ............................... .
Section 4. Keyboard .................................. .
Section 5. System
BIOS ............................... .
Section 6. Instruction Set
xiii

xiv

Section 7. Characters, Keystrokes, and Colors .............. .
Section
8. Communications
Glossary
........................................... .
Bibliography
........................................ .
Index
.............................................. .
xv

xvi

System BlockDiagram
The following is a system block diagram of the IBM Personal
Computer.
Expansion Unit
System Board
ExPinsion Board
Oscillitor
Cassette
8088
Adapter
Oscillator
8 Interrupt Spe.ker
Levels
Adapter
4 Channels
Direct Memory
Ac ....
keyboard
Adlpttr
Memory
Rod-Only
Memory
Math
Coprocessor
(Optional)
• Slot Expanded
I/O Channel
Receivar
Card
5 Slot
I/O Channel
Extender end
Note: A "System to Adapter Compatibility Chart," to
identify the adapters supported by each system, and an
"Option to Adapter Compatibility Chart," to identify the
options supported by each adapter, can
be found in the front
matter of the Technical Reference options and adapters
manual, Volume
1.
xvii

xviii

SECTION 1. SYSTEMBOARD
Contents
Description
1-3
Microprocessor ....................••...........•• 1-3
Data Flow Diagrams ••••........•.....•............ 1-5
System Memory Map .......•...........•.......... 1-8
System Timers ........................•.......... 1-11
System Interrupts
•.•............••..••.......••.. 1-11
ROM ..............................•.......... 1-13
RAM ..•••.••..........•.••••...•....••.••.•... 1-13
DMA .......................................... 1-13
110 Channel ...•.••.............••.••..........• 1-14
System Board Diagram ......•.•...........•....... 1-16
1/0 Channel Diagram •.•.........•••••.........•.• 1-18
I/O Channel Description ..........••...•.........•• 1-20
110 Address Map ................................ 1-24
Other Circuits ................................... 1- 25
Speaker Circuit
............................... 1-25
Cassette Interface
............................. 1-27
Cassette Circuit Block Diagrams
.................. 1-28
8255A I/O Bit Map ........................... 1-31
System-Board Switch Settings
.................... 1-33
System Board
1-1