Table Of ContentFEDERAL COMMUNICATIONS COMMISSION
RADIO FREQUENCY INTERFERENCE
STATEMENT
WARNING: This equipment has been certified to comply with
the limits for a Class B computing device,
pursuant to Subpart J of Part 15 of FCC rules,
Only peripherals (computer inputloutput devices,
terminals, printers, etc.) certified to comply with
the Class B limits may be attached to this
computer. Operation with non-certified
peripherals is likely to result in interference to
radio and TV reception.
Notice: As sold by the manufacturer, the IBM Prototype Card
does not require certification under the FCC's rules for Class B
devices. The user is responsible for any interference to radio or TV
reception which may be caused by a user-modified prototype card.
CAUTION: This product is equipped with a UGlisted and
CSA-certified plug for the user's safety. It is to be
used in conjunction with a properly grounded
115 Vac receptacle to avoid electrical shock.
Revised Edition (April 1983)
Changes are periodically made to the information herein; these changes will be
incorporated in new editions of this publication.
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.
A Reader's Comment Form is provided at the back of this publication. If this 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.
O Copyright International Business Machines Corporation, 1981, 1982, 1983
PREFACE
-
The IBM Personal Computer XT Technical Reference manual
describes the hardware design and provides interface information
for the IBM Personal Computer XT. This publication also has
information about the basic inputloutput system (BIOS) and
programming support.
The information in this publication is both introductory and for
reference, and is intended for hardware and software designers,
programmers, engineers, and interested persons who need to
understand the design and operation of the computer.
You should be familiar with the use of the Personal Computer
XT, and you should understand the concepts of computer
architecture and programming.
This manual has two sections:
"Section 1: Hardware" describes each functional part of the
system. This section also has specifications for power, timing, and
interface. Programming considerations are supported by coding
tables, command codes, and registers.
"Section 2: ROM BIOS and System Usage" describes the basic
inputloutput 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.
The publication has seven appendixes:
Appendix A: ROM BIOS Listings
Appendix B: 8088 Assembly Instruction Set Reference
. Appendix C: Of Characters, Keystrokes, and Color
Appendix I3 Logic Diagrams
Appendix E: Specifications
Appendix F: Communications
Appendix G: Switch Settings
A glossary and bibliography are included.
iii
Prerequisite Publication:
Guide to Operations for the IBM Personal Computer XT
Part Number 6936810
Suggested Reading:
BASIC for the LBM Personal Computer
Part Number 6025010
Disk Operating System (DOS) for the IBM Personal Computer
Part Number 602406 1
Hardware Maintenance and Service for the IBM Personal
Computer XT
Part Number 6936809
MACRO Assembler for the IBM Personal Computer
Part Number 6024002
Related publications are listed in the bibliography.
TABLE OF CONTENTS
.
Section 1: Hardware
IBM Personal Computer XT System Unit . . . . . . . . . . . . . 1-3
IBM Personal Computer Math Coprocesser . . . . . . . . . . . . 1-25
IBM Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-65
IBM Expansion Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-71
IBM 80 CPS Printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-81
IBM Printer Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 1 07
IBM Monochrome Display and Printer Adapter . . . . . . . . 1-11 3
IBM Monochrome Display . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 1 21
IBM Color/Graphics Display Adapter . . . . . . . . . . . . . . . . 1. 1 23
IBM Color Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 1 49
IBM 5 4 " Diskette Drive Adapter . . . . . . . . . . . . . . . . . . . 1-15 1
IBM 5-%" Diskette Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 75
Diskettes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 1 77
IBM Fixed Disk Drive Adapter . . . . . . . . . . . . . . . . . . . . . . 1-17 9
IBM lOMB Fixed Disk Drive . . . . . . . . . . . . . . . . . . . . . . . 1. 1 95
IBM Memory Expansion Options .................... 1. 1 97
IBM Game Control Adapter . . . . . . . . . . . . . . . . . . . . . . . . . 1-203
IBM Prototype Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-209
IBM Asynchronous Communications Adapter .......... 1-21 5
IBM Binary Synchronous Communications Adapter . . . . . 1-245
IBM Synchronous Data Link Control (SDLC)
Communication Adapter .......................... 1-265
IBM Communications Adapter Cable . . . . . . . . . . . . . . . . . 1-295
Section 2:ROM BIOS and System Usage
ROM BIOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Keyboard Encoding and Usage . . . . . . . . . . . . . . . . . . . . . . 2-11
Appendix A: ROM BIOS Listings . . . . . . . . . . . . . . A-1
System BIOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Fixed Disk BIOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-85
Appendix B: 8088 Assembly Instruction
Set Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
A.p. p endix C: Of Characters. Keystrokes.
and Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Appendix D: Logic. Diagrams . . . . . . . . . . . . . . . . . . . D-1
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2 .
Type 1 Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-12
Type 2 Keyboard ................................. D-14
Expansion Board .................................. D-1 5
Extender Card .................................... D-1 6
Receiver Card .................................... D-1 9
Printer . .......................................... D-22
Printer Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-25
Monochrome Display Adapter . . . . . . . . . . . . . . . . . . . . . . D-26
Color/Graphics Monitor Adapter . ................... D-36
Color Display .................................... D-42
Monochrome Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-44
5-% Inch Diskette Drive Adapter . ................... D-45
5-% Inch Diskette Drive. T ype 1 . . . . . . . . . . . . . . . . . . . D-49
5-'/4 Inch Diskette Drive. T ype 2 ................... D-52
Fixed Disk Drive Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . D-54
Fixed Disk Drive. T ype 1 . . . . . . . . . . . . . . . . . . . . . . . . . D-60
Fixed Disk Drive. T ype 2 . . . . . . . . . . . . . . . . . . . . . . . . . D-63
32K Memory Expansion Option .. . . . . . . . . . . . . . . . . . . . D-66
64K Memory Expansion Option . . . . . . . . . . . . . . . . . . . . . D-69
641256K Memory Expansion Option . . . . . . . . . . . . . . . . . D-72
Game Control Adapter ............................. D-76
Prototype Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-77
Asynchronous Communications Adaptei .............. D-78
Binary Synchronous Communications Adapter . . . . . . . . . D-79
SDLC Communications Adapter . . . . . . . . . . . . . . . . . . . . D-81
Appendix E: Specifications .. . . . . . . . . . . . . . . . . . . . E-1
Appendix F: Communications . . . . . . . . . . . . . . . . . . F- 1
Appendix G: Switch Settings . . . . . . . . . . . . . . . . . . . G-1
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H- 1
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I- 1
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I viii
I
Notes:
