IBM PC 100 User manual

IBM
Technical Information Manual
PC 100 (Type 6260) and PC 300 (Type 6560)
S78H-5142-00

IBM Technical Information Manual
PC 100 (Type 6260) and PC 300 (Type 6560)
S78H-5142-00

Note
Before using this information and the product it supports, be sure to read the general information under
Appendix B, “Notices and Trademarks” on page 43.
First Edition (August 1996)
The following 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 PUBLICATION “AS IS” WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow disclaimer of express or implied
warranties in certain transactions, therefore, this statement may not apply to you.
This publication could include technical inaccuracies or typographical errors. Changes are periodically made to the information
herein; these changes will be incorporated in new editions of the publication. IBM may make improvements and/or changes in the
product(s) and/or the program(s) described in this publication at any time.
It is possible that this publication may contain reference to, or information about, IBM products (machines and 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.
Requests for technical information about IBM products should be made to your IBM reseller or IBM marketing representative.
 Copyright International Business Machines Corporation August 1996. All rights reserved.
Note to U.S. Government Users — Documentation related to restricted rights — Use, duplication or disclosure is subject to
restrictions set forth in GSA ADP Schedule Contract with IBM Corp.

Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Related Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Manual Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Chapter 1. System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Personal Computer Description .......................................... 2
System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
System Address Maps ............................................... 7
Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Input/Output Address Map ........................................... 7
DMA I/O Address Map ............................................. 9
IRQ and DMA Channel Assignments ...................................... 10
Interrupt Request Assignments (IRQ) .................................... 10
DMA Channel Assignments .......................................... 10
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Power Output Parameters ............................................. 11
Component Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Connector Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Physical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Advanced Power Management (APM) ...................................... 14
Chapter 2. Connectors and Jumpers ..................................... 15
System Board Connectors ............................................ 16
Diskette Drive Connector ............................................ 16
Hard Disk Drive Connectors (Primary/Secondary) ............................. 17
ISA Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
PCI Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Power Supply Connectors ........................................... 20
System Board Memory Connectors ...................................... 21
Video Feature Connector ............................................ 22
I/O Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Keyboard and Auxiliary-Device (Mouse) Connectors ............................ 23
Serial Port Connectors ............................................. 24
Parallel Port Connector ............................................. 25
Monitor Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Chapter 3. Memory Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Memory-Module Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Memory-Module Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Cache Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Cache Upgrade Options ............................................ 30
Chapter 4. System Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Hardware Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Diskette Drives and Controller ......................................... 33
Hard Disk Drives and Controller ........................................ 34
 Copyright IBM Corp. August 1996 iii

Software Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Software Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Machine-Sensitive Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
BIOS Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Chapter 5. Bus Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Bus Architecture Descriptions ........................................... 37
ISA Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
PCI Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Expansion-Bus Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Bus Voltage Levels ............................................... 39
Appendix A. Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
POST Error Codes ................................................. 40
Beep Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Appendix B. Notices and Trademarks .................................... 43
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
iv Technical Information Manual

Figures
1. System Board Devices, Features, and Options ............................. 4
2. System Board Diagram ........................................... 6
3. System Memory Map ............................................ 7
4. I/O Address Map ............................................... 7
5. DMA I/O Addresses for Memory Addresses, Word Counts, and Command/Status Registers ... 9
6. Interrupt Request Assignments ...................................... 10
7. DMA Channel Assignments ........................................ 10
8. AC Input Power Requirements ....................................... 11
9. Power Output Parameters (145 Watt) ................................... 11
10. Component Maximum Current ....................................... 12
11. Physical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
12. Advanced Power Management Modes .................................. 14
13. Diskette Drive Connector Signal and Pin Assignments ......................... 16
14. EIDE Connector Signal and Pin Assignments .............................. 17
15. I/O Channel (ISA Bus) Connector ..................................... 18
16. PCI Connector Signal and Pin Assignments ............................... 19
17. Power Supply Connector (Internal Devices) Signal and Pin Assignments .............. 20
18. Power Supply Connector (System Board) Signal and Pin Assignments ............... 20
19. System Board Memory Connector Signal and Pin Assignments ................... 21
20. Video Feature Connector .......................................... 22
21. Keyboard Signal and Pin Assignments .................................. 23
22. Auxiliary-Device (Mouse) Signal and Pin Assignments ......................... 23
23. Serial Port Connector Signal and Pin Assignments ........................... 24
24. Parallel Port Connector Signal and Pin Assignments .......................... 25
25. Monitor Connector Signal and Pin Assignments ............................. 27
26. Memory-Module Type, Speed, and Size – PC 100 ........................... 29
27. Memory-Module Type, Speed, and Size – PC 300 ........................... 29
28. System Memory Table ........................................... 29
29. L1 and L2 Cache .............................................. 30
30. Features of IBM Option Kit 76H0236 ................................... 30
31. 5.25-Inch Diskette Drive Reading, Writing, and Formatting Capabilities ............... 33
32. 3.5-Inch Diskette Drive Reading, Writing, and Formatting Capabilities ................ 33
33. POST Error Messages – PC 100 and PC 300 .............................. 40
34. Beep Codes – PC 100 ........................................... 42
35. Beep Codes – PC 300 ........................................... 42
 Copyright IBM Corp. August 1996 v

Preface
This Technical Information Manual provides information about the IBM PC 100 (Type 6260) and the IBM
PC 300 (Type 6560). It is intended for developers who want to provide hardware and software products to
operate with these IBM computers and provides a more in-depth view of how the computers work. Users
of this publication should have an understanding of computer architecture and programming concepts.
Related Publications
In addition to this manual, the following IBM publications provide information related to the operation of the
PC 100 and PC 300. To order publications in the U.S. and Puerto Rico, call 1-800-879-2755. In other
countries, contact an IBM reseller or an IBM marketing representative.

Using Your Personal Computer – PC 100
1
 Hardware Maintenance Manual – PC 100
1
 Using Your Personal Computer – PC 300
 Installing Options in Your Personal Computer – PC 300
 Understanding Your Personal Computer – PC 300
 Hardware Maintenance Manual – PC 300
Manual Style
Attention: The term reserved describes certain signals, bits, and registers that should not be changed.
Use of reserved areas can cause compatibility problems, loss of data, or permanent damage to the
hardware. When the contents of a register are changed, the state of the reserved bits must be preserved.
When possible, read the register first and change only the bits that must be changed.
In this manual, signals are represented in a small, all-capital-letter format (-ACK). A minus sign in front of
the signal indicates that the signal is active low. No sign in front of the signal indicates that the signal is
active high.
In this manual, use of the letter “h” indicates a hexadecimal number. Also, when numerical modifiers such
as “K”, “M” and “G“ are used, they typically indicate powers of 2, not powers of 10 (unless expressing hard
disk storage capacity). For example, 1 KB equals 1024 bytes (2 10), 1 MB equals 1048576 bytes (2 20),
and 1 GB equals 1073741824 bytes (230).
When expressing storage capacity, MB equals 1000 KB (1024000). The value is determined by counting
the number of sectors and assuming that every two sectors equals 1 KB.
The actual storage capacity available to the user can vary, depending on the operating system and other
system requirements.
1Not available in the U.S. and Puerto Rico.
vi  Copyright IBM Corp. August 1996

Chapter 1. System Description
Chapter 1. System Description
Personal Computer Description .......................................... 2
System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
System Address Maps ............................................... 7
Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Input/Output Address Map ........................................... 7
DMA I/O Address Map ............................................. 9
IRQ and DMA Channel Assignments ...................................... 10
Interrupt Request Assignments (IRQ) .................................... 10
DMA Channel Assignments .......................................... 10
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Power Output Parameters ............................................. 11
Component Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Connector Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Physical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Advanced Power Management (APM) ...................................... 14
 Copyright IBM Corp. August 1996 1

Chapter 1. System Description
Personal Computer Description
The IBM PC 100 (Type 6260) and PC 300 (Type 6560) are versatile products designed to provide
state-of-the-art computing power with room for growth in the future. The two computer models are similar
in design, utilizing the same cover, frame assembly, and system board. They differ in the type of BIOS
resident and in the mix of standard features.
The major features of the PC 100 and PC 300 are:
Intel Pentium microprocessor
Up to 128 MB of system memory
Cirrus GD5436 video subsystem
1 MB of video memory with sockets for additional 1 MB
Industry-standard compatibility
ISA/PCI I/O-bus compatibility
ISA/PCI expansion slots
Enhanced EIDE hard disk drive
Bus master-capable EIDE controller
Two 16550-UART serial ports (serial A and serial B)
L2 cache sockets for pluggable SRAMS (256 KB)
Support for advanced power management
EnergyStar compliant
Support for Plug and Play adapters and monitors
Security features
System unit size
– Four expansion slots
– Four drive bays
Note: Several model variations are available for both the PC 100 and the PC 300.
2Technical Information Manual

Chapter 1. System Description
System Overview
Data Buffers
Control
(ISA, DMA,
IRQ)
CMOS, Flash
I/O Control
Keyboard,
Mouse Ports
Serial Ports
Hard
Disk Drive,
CD-ROM
Parallel Port
Video
Port
Diskette Drive
EIDE Control Video Control,
DRAM Riser Card
(ISA/PCI Slots)
Memory
(DRAM)
Controls
(Memory,
L2 Cache,
PCI)
L2 Cache
(SRAM)
Sockets
Microprocessor
- Coprocessor
- L1 Cache
Processor (Local) Bus - 64-Bit
PCI I/O Bus - 32-Bit
ISA I/O Bus - 16-Bit
. .
Chapter 1. System Description 3

Chapter 1. System Description
System Features
The following figure lists the devices and features of the PC 100 and PC 300 system board. It also
includes some of the options that may be added to these computers.
Figure 1 (Page 1 of 2). System Board Devices, Features, and Options
Device Features
Microprocessor Intel Pentium (75/100/120/133 MHz)2
32-bit address bus, 64-bit data bus
8 KB internal (L1) write-through code cache
8 KB internal (L1) write-back data cache
Superscalar architecture (two execution units)
Math coprocessor function included in the Pentium
Microprocessor is upgradable for future Intel microprocessor technology
External Cache (L2) DIP sockets for user-installable data/tag RAMs
256 KB asynchronous write-back unified (code and data)
Video Subsystem Cirrus Logic GD5436 SVGA video controller
Plug and Play monitor support (DDC2)
Advanced Power Management
Local peripheral bus (LPB) interface
64-bit data path width on PCI bus
Integrated DAC
64-bit graphics accelerator
1 MB of 70 ns FP DRAM
Fast Page Mode DRAM
Sockets for additional 1 MB
Bus Architecture ISA/PCI-bus-compatible I/O expansion slots
Synchronous 25/30/33 MHz PCI bus
50/60/66 MHz processor bus
Integrated L2 cache controller
Flash ROM Subsystem 256 KB flash ROM for POST/BIOS
RAM Subsystem 8 MB standard DRAM, upgradable to 128 MB
70-ns fast page (FP) or 60-ns extended data output (EDO), non-parity, dynamic
random access memory (DRAM)
Four 72-pin SIMM sockets in two banks
SIMMs (4 MB, 8 MB, 16 MB, or 32 MB)
Matched pairs required in each bank
CMOS RAM Subsystem 128-byte CMOS RAM with real-time clock, calendar, and battery
ISA/PCI Bridge ISA/PCI interface
PCI bus-master EIDE interface
ISA-compatible interrupt controller
ISA-compatible DMA controller
DMA Controller Seven AT-compatible DMA channels
Four 8-bit channels
Three 16-bit channels
Interrupt Controller 15 levels of system interrupts
AT bus interrupts are edge triggered
PCI bus interrupts are level sensitive
System Timers Channel 0–System timer
Channel 1–Refresh generation
Channel 2–Tone generation for speaker
Audio Subsystem On-board Piezo electric beeper
2MHz denotes internal clock speed of the microprocessor only; other factors might also affect application performance.
4Technical Information Manual

Chapter 1. System Description
Figure 1 (Page 2 of 2). System Board Devices, Features, and Options
Device Features
Diskette Drive Controller Controller supports up to two internal diskette drives
A 3.5-in. diskette drive (1.44 MB) is standard
A 5.25-in. diskette drive (1.2 MB) is optional
A second 3.5-in. diskette drive (1.44 MB) is optional and requires a 3.5-in.
conversion kit for a 5.25-in. bay
FIFO operations
Keyboard/Auxiliary-Device
Controller 101-key or 104-key keyboard Keyboard connector
Auxiliary-device (mouse) connector
Parallel Port Controller One ECP/EPP parallel port
Supports standard I/O mode, extended capabilities port (ECP) mode, and
enhanced parallel port (EPP) mode
Serial Port Controller Two 16550-UART serial ports (Serial A and B)
Hard Disk Drive Controller Controller supports four EIDE devices
PCI bus-master EIDE interface
Two PCI bus-master channels
One channel for each EIDE connector (primary and secondary)
SCSI hard disk drives require a PCI SCSI adapter
Power 145 watt (115/230 V ac, 50/60 Hz) power supply
Built-in overload and surge protection
Advanced Power Management
Security Power-on password
Administrator password
Startup sequence control
Unattended Start mode
Diskette I/O control
Hard disk I/O control
Chapter 1. System Description 5

Chapter 1. System Description
System Board
The following is a diagram of the PC 100 and PC 300 system board. Note that the system board for
these computers might differ slightly from the one shown. A diagram of the system board, including switch
and jumper settings, is provided on the underside of the computer cover.
.1/ J3 Power connector (5 V)
.2/ JP11 Flash jumper
.3/ JP21 FDD write protect
.4/ JP4 PS/2 mouse enable/disable
.5/ J5 Diskette drive connector
.6/ JP23 HDD detect
.7/ J8 Primary IDE connector
.8/ J7 Secondary IDE connector
.9/ Battery
.1ð/ J9 Password jumper (CMOS clear)
.11/ L2 cache memory sockets
.12/ JP22 Burst mode
.13/ JP19 CPU voltage
.14/ Processor socket
.15a/ J12 Power LED connector
.15b/ J12 Hard disk drive LED connector
.16/ J13 CPU fan connector
.17/ JP17 CPU clock
.18/ SIMM connector 1 - Bank 1
.19/ SIMM connector 2 - Bank 1
.2ð/ SIMM connector 3 - Bank 0
.21/ SIMM connector 4 - Bank 0
.22/ Tag RAM socket
.23/ J6 Video feature connector
.24/ JP13 Cache memory size
.25/ JP14 CPU bus clock
.26/ JP3 On-board VGA
.27/ P4 Monitor (display) port
.28/ P1 Parallel port3
.29/ Video memory sockets
.3ð/ P2 Serial (B) port
.31/ PCI/ISA riser connector
.32/ P3 Serial (A) port
.33/ J2 Auxiliary device (mouse) port
.34/ J1 Keyboard port
Figure 2. System Board Diagram
25
1
33 34
2
3
4
5
6
7
8
9
10
12
13
11
15a
15b 141617
1819
20
21
22
2323
24
26
27 29 30 31 3232
28
3Extended capabilities port/enhanced parallel port (ECP/EPP)
6Technical Information Manual

Chapter 1. System Description
System Address Maps
Memory Map
The first 640 KB of system board RAM is mapped starting at address 0000000h. A 256-byte area and a 1
KB area of this RAM are reserved for BIOS data areas. Memory can be mapped differently if POST
detects an error. See the section about BIOS data areas in the IBM Personal System/2 and Personal
Computer BIOS Interface Technical Reference for details.
Input/Output Address Map
The following figures list the system board I/O address maps. Any addresses that are not shown are
reserved.
Figure 3. System Memory Map
Address Range
(Decimal) Address Range (Hex) Size Description
1024K–131072K 100000–8000000 127M Extended memory
960K–1023K F0000–FFFFF 64K System BIOS
944K–959K EC000–EFFFF 16K Available
936K–943K EA000–EBFFF 8K ESCD (Plug and Play configuration area)
928K–935K E8000-E9FFF 8K Available
896K–927K E0000–E7FFF 32K BIOS reserved
800K–895K C8000–DFFFF 96K Available HI DOS memory (open to ISA and PCI bus)
640K–799K A0000–C7FFF 160K Video memory and BIOS
512K–639K 80000–9FFFF 128K Extended
0K–511K 00000–7FFFF 512K DOS applications (conventional)
Figure 4 (Page 1 of 3). I/O Address Map
Address (Hex) Device
0000–000F DMA 1
0020–003F Interrupt controller 1
0040–0043 Timer 1
0044–0047 Available I/O for ISA/PCI bus
0048–004B Timer 2
004C–005F Available I/O for ISA/PCI bus
0060 Keyboard controller data byte
0061 System Port B
0062–0063 Available I/O for ISA/PCI bus
0064 Keyboard controller, command and status byte
0065–006F Available I/O for ISA/PCI bus
0070, bit 7 Enable/disable NMI
0070, bits 6:0 Real time clock address
0071 Real time clock data
0072–0077 Available I/O for ISA/PCI bus
0078 Reserved-system board setup
0079 Reserved-system board setup
007A–007F Available I/O for ISA/PCI bus
0080 POST checkpoint register
0080-008F DMA page register
0090–009F Available I/O for ISA/PCI bus
00A0–00BF Interrupt controller 2
00C0–00DE DMA 2
00DF–00EF Available I/O for ISA/PCI bus
Chapter 1. System Description 7

Chapter 1. System Description
Figure 4 (Page 2 of 3). I/O Address Map
Address (Hex) Device
00F0 Coprocessor busy–Clear
00F1 Coprocessor reset
00F2–016F Available I/O for ISA/PCI bus
0170–0177 IDE channel 1
01F0–01F7 IDE channel 0
01F8–021F Available I/O for ISA/PCI bus
0220–0227 SMC FD-37C669, serial port 3 or 4
0228–0277 Available I/O for ISA/PCI bus
0278–027F SMC FD-37C669, parallel port 3
0280–02E7 Available I/O for ISA/PCI bus
02E8–02EF SMC FD-37C669, serial port 3 or 4
02F0–02F7 Available I/O for ISA/PCI bus
02F8–02FF SMC FD-37C669, serial port 2 (system board)
0300–0337 Available I/O for ISA/PCI bus
0338–033F SMC FD-37C669, serial port 3 or 4
0340–0375 Available I/O for ISA/PCI bus
0376–0377 IDE channel 1
0377, bit 7 IDE, diskette change
0378–037F SMC FD-37C669, parallel port 2
0380–03B0 Available I/O for ISA/PCI bus
03BC–03BE SMC FD-37C669, parallel port 1 (system board)
03E0–03E7 Available I/O for ISA/PCI bus
03E8–03EF SMC FD-37C669, serial port 3 or 4
03F0–03F5 SMC FD-37C669, diskette channel 0
03F6 IDE channel 0
03F7, bit 7 IDE, diskette change
03F7, bits 6:0 IDE channel 0
03F8–03FF SMC FD-37C669, serial port 1 (system board)
0400–0537 Available I/O for ISA/PCI bus
0CF8–0CFB PCI configuration address register
0CFC–0CFF PCI configuration data registers
0D00–0E7F Available I/O for ISA/PCI bus
0E80–0E87 Available I/O for ISA/PCI bus
0E88–0F3F Available I/O for ISA/PCI bus
0F40–0F47 Available I/O for ISA/PCI bus
0F47–042E7 Available I/O for ISA/PCI bus
42E8 Cirrus GD5436
42E9–4AE7 Available I/O for ISA/PCI bus
4AE8 Cirrus GD5436
4AE9–82E7 Available I/O for ISA/PCI bus
82E8 Cirrus GD5436
82E9–86E7 Available I/O for ISA/PCI bus
86E8 Cirrus GD5436
86E9–8AE7 Available I/O for ISA/PCI bus
8AE8 Cirrus GD5436
8AE9–8EE7 Available I/O for ISA/PCI bus
8EE8 Cirrus GD5436
8EE9–92E7 Available I/O for ISA/PCI bus
92E8 Cirrus GD5436
92E9–96E7 Available I/O for ISA/PCI bus
96E8 Cirrus GD5436
96E9–9AE7 Available I/O for ISA/PCI bus
9AE8 Cirrus GD5436
9AE9–9EE7 Available I/O for ISA/PCI bus
9EE8 Cirrus GD5436
9EE9–A2E7 Available I/O for ISA/PCI bus
A2E8 Cirrus GD5436
A2E9–A6E7 Available I/O for ISA/PCI bus
A6E8 Cirrus GD5436
A6E9–AAE7 Available I/O for ISA/PCI bus
AAE8 Cirrus GD5436
AAE9–B2E7 Available I/O for ISA/PCI bus
B2E8 Cirrus GD5436
8Technical Information Manual

Chapter 1. System Description
DMA I/O Address Map
Figure 4 (Page 3 of 3). I/O Address Map
Address (Hex) Device
B2E9–B6E7 Available I/O for ISA/PCI bus
B6E8 Cirrus GD5436
B6E9–BAE7 Available I/O for ISA/PCI bus
BAE8 Cirrus GD5436
BAE9–BEE7 Available I/O for ISA/PCI bus
BEE8 Cirrus GD5436
BEE9–E2E7 Available I/O for ISA/PCI bus
E2E8 Cirrus GD5436
E2E9 Available I/O for ISA/PCI bus
E2EA Cirrus GD5436
E2EB–FFFF Available I/O for ISA/PCI bus
Figure 5 (Page 1 of 2). DMA I/O Addresses for Memory Addresses, Word Counts, and Command/Status
Registers
Address (hex) Description Bits Byte Pointer
0000 Channel 0, Memory Address register 00–15 Yes
0001 Channel 0, Transfer Count register 00–15 Yes
0002 Channel 1, Memory Address register 00–15 Yes
0003 Channel 1, Transfer Count register 00–15 Yes
0004 Channel 2, Memory Address register 00–15 Yes
0005 Channel 2, Transfer Count register 00–15 Yes
0006 Channel 3, Memory Address register 00–15 Yes
0007 Channel 3, Transfer Count register 00–15 Yes
0008 Channels 0–3, Read Status/Write Command
register 00–07
0009 Channels 0–3, Write Request register 00–02
000A Channels 0–3, Write Single Mask register bits 00–02
000B Channels 0–3, Mode register (write) 00–07
000C Channels 0–3, Clear byte pointer (write) N/A
000D Channels 0–3, Master clear (write)/temp (read) 00–07
000E Channels 0–3, Clear Mask register (write) 00–03
000F Channels 0–3, Write All Mask register bits 00–03
0081 Channel 2, Page Table Address registerñ 00–07
0082 Channel 3, Page Table Address registerñ 00–07
0083 Channel 1, Page Table Address registerñ 00–07
0087 Channel 0, Page Table Address registerñ 00–07
0089 Channel 6, Page Table Address registerñ 00–07
008A Channel 7, Page Table Address registerñ 00–07
008B Channel 5, Page Table Address registerñ 00–07
008F Channel 4, Page Table Address/Refresh register 00–07
00C0 Channel 4, Memory Address register 00–15 Yes
00C2 Channel 4, Transfer Count register 00–15 Yes
00C4 Channel 5, Memory Address register 00–15 Yes
00C6 Channel 5, Transfer Count register 00–15 Yes
00C8 Channel 6, Memory Address register 00–15 Yes
00CA Channel 6, Transfer Count register 00–15 Yes
00CC Channel 7, Memory Address register 00–15 Yes
00CE Channel 7, Transfer Count register 00–15 Yes
00D0 Channels 4–7, Read Status/Write Command
register 00–07
00D2 Channels 4–7, Write Request register 00–02
00D4 Channels 4–7, Write Single Mask register bit 00–02
00D6 Channels 4–7, Mode register (write) 00–07
00D8 Channels 4–7, Clear byte pointer (write) N/A
00DA Channels 4–7, Master clear (write)/temp (read) 00–07
00DC Channels 4–7, Clear Mask register (write) 00–03
00DE Channels 4–7, Write All Mask register bits 00–03
Chapter 1. System Description 9

Chapter 1. System Description
IRQ and DMA Channel Assignments
The following figures list the interrupt request (IRQ) and direct memory access (DMA) channel
assignments.
Interrupt Request Assignments (IRQ)
DMA Channel Assignments
Figure 5 (Page 2 of 2). DMA I/O Addresses for Memory Addresses, Word Counts, and Command/Status
Registers
Address (hex) Description Bits Byte Pointer
00DF Channels 5–7, 8- or 16-bit mode select 00–07
ñUpper byte of Memory Address register
Figure 6. Interrupt Request Assignments
Interrupt
Request (IRQ) System Resource
NMI Critical system error
SMI System/power management interrupt
0 Reserved (internal timer)
1 Reserved (keyboard buffer full)
2 Reserved (cascade interrupt from slave)
3 Serial port 2ñ
4 Serial port 1ò
5 Parallel port 2ñ
6 Diskette controllerò
7 Parallel port 1ò
8 Reserved (real-time clock)
9 Video adapter (if installed)ñ
10 ISA/PCI bus
11 ISA/PCI bus
12 Mouse portñ
13 Reserved (math coprocessor)
14 IDE Channel 1ñ
15 IDE Channel 2ò
ñIf not assigned, this resource is available for the ISA/PCI bus.
òIf not assigned, this resource is available for the ISA bus.
Figure 7. DMA Channel Assignments
DMA
Channel Data Width System Resource
0 8 bits ISA busñ
1 8 bits ISA busñ
2 8 bits Reserved (diskette drive)
3 8 bits ECP/EPP parallel portñ
4 Reserved (cascade channel)
5 16 bits ISA bus
6 16 bits ISA bus
7 16 bits ISA bus
ñIf not assigned, this resource is available for the ISA bus.
10 Technical Information Manual

Chapter 1. System Description
Power Supply
The power supply converts the ac input voltage into four dc output voltages and provides power for the
following:
System board
Adapters
Internal DASD drives
Keyboard and auxiliary devices
PC 100 and PC 300 computers have a 145-watt power supply. The following figure shows the input
power specifications. The power available for each component within the system is shown in Figure 10
on page 12.
Power Output Parameters
The power supply dc outputs shown in the following figure include the current supply capability of all the
connectors including system board, DASD, PCI, and auxiliary outputs.
Figure 8. AC Input Power Requirements
Specification Measurements
Input voltage (Range is switch selected; sine wave input is required.)
Low range 110 (min)–127 (max) V ac
High range 200 (min)–240 (max) V ac
Input frequency 50 Hz ± 3 Hz or 60 Hz ± 3 Hz
Figure 9. Power Output Parameters (145 Watt)
Output Voltage Regulation Minimum Current (amps) Maximum Current (amps)
+5 volts +5% to -4% 1.5 A 18.0 A
+12 volts +5% to -4% 0.2 A 4.2 A
-12 volts +10% to -9% 0.0 A 0.4 A
-5 volts +5% to -4% 0.0 A 0.3 A
Chapter 1. System Description 11

Chapter 1. System Description
Component Outputs
The power supply provides separate voltage sources for the system board and internal storage devices.
The following figure shows the approximate power that is provided for system components. Many
components draw less current than the maximum shown.
Note: Some adapters and hard disk drives draw more current than the recommended limits. These
adapters and drives can be installed in the system; however, the power supply will shut down if the
total power used exceeds the maximum power that is available.
Output Protection
The power supply protects against output overcurrent, overvoltage, and short circuits. Please see the
power supply specifications for details.
A short circuit that is placed on any dc output (between outputs or between an output and dc return)
latches all dc outputs into a shutdown state, with no damage to the power supply.
If this shutdown state occurs, the power supply returns to normal operation only after the fault has been
removed and the power switch has been turned off for at least one second.
If an overvoltage fault occurs (in the power supply), the power supply latches all dc outputs into a
shutdown state before any output exceeds 130% of the nominal value of the power supply.
Figure 10. Component Maximum Current
Supply Voltage (V dc) Maximum Current (mA) Regulation Limits
System Board:
+5.0 V dc 4000 mA +5.0% to −5.0%
+12.0 V dc 25.0 mA +5.0% to −5.0%
−12.0 V dc 25.0 mA +10.0% to −9.0%
Keyboard Port:
+5.0 V dc 275 mA +5.0% to −5.0%
Auxiliary-Device (Mouse) Port:
+5.0 V dc 300 mA +5.0% to −5.0%
AT-Bus Adapters (Per Slot):
+5.0 V dc 4500 mA +5.0% to −5.0%
−5.0 V dc 200 mA +5.0% to −5.0%
+12.0 V dc 1500 mA +5.0% to −5.0%
−12.0 V dc 300 mA +5.0% to −5.0%
PCI-Bus Adapters (Per Slot)
+5.0 V dc 5000 mA +5.0% to −4.0%
Internal DASD:
+5.0 V dc 1400 mA +5.0% to −5.0%
+12.0 V dc 1500 mA +5.0% to −5.0%
12 Technical Information Manual