IBM PS/2 90 XP 486 Owner's manual

FRONT
PICTURE 1
July 1992
Part Number 10G6475
Form Number S10G-6475-00
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
¦ Copyright IBM Corp. 1990, 1992
FRONT - 1

EDITION Edition Notice
Safety Information
Refer to the Hardware Maintenance Reference General Information
pamphlet for the following safety information:
General Safety
Electrical Safety.
First Edition (July 1992)
The following paragraph does not apply to the United Kingdom or any
country where such provisions are inconsistent with local law:
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"AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED,
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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.
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Requests for technical information about IBM products should be made
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IBM may have patents or pending patent applications covering subject
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inquiries, in writing, to the IBM Director of Commercial Relations,
IBM Corporation, Purchase, NY 10577.
¦ Copyright International Business Machines Corporation 1990, 1992.
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.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Edition Notice
¦ Copyright IBM Corp. 1990, 1992
EDITION - 1

FRONT_1 Notices
References in this publication to IBM products, programs, or services do
not imply that IBM intends to make these available in all countries in
which IBM operates. Any reference to an IBM product, program or service
is not intended to state or imply that only IBM's product, program, or
service may be used. Any functionally equivalent product, program, or
service that does not infringe any of IBM's intellectual property rights
or other legally protectible rights may be used instead of the IBM
product, program, or service. Evaluation and verification of operation in
conjunction with other products, programs, or services, except those
expressly designated by IBM, are the user's responsibility.
IBM may have patents or pending patent applications covering subject
matter in this document. The furnishing of this document does not give
you any license to these patents. You can send license inquiries, in
writing, to the IBM Director of Commercial Relations, IBM Corporation,
Purchase, NY 10577.
The following terms, denoted by an asterisk (*) in this publication, are
trademarks of the IBM Corporation in the United States and/or other
countries:
+------------------------------------------------------------------------+
¦ IBM ¦ Presentation Manager ¦ OS/2 ¦
¦ XGA ¦ Personal System/2 ¦ Micro Channel ¦
¦ PS/2 ¦ ¦ ¦
+------------------------------------------------------------------------+
The following terms, denoted by a double asterisk (**) in this
publication, are trademarks of other companies:
+------------------------------------------------------------------------+
¦ Windows ¦ Microsoft Corporation ¦
+------------------------------------------------------------------------+
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Notices
¦ Copyright IBM Corp. 1990, 1992
FRONT_1 - 1

CONTENTS Table of Contents
EDITION Edition Notice
FRONT_1 Notices
CONTENTS Table of Contents
1.0 Product Description (Model 90 XP 486)
2.0 Product Description (Model 95 XP 486)
2.1 Security
2.1.1 Cover Lock
2.1.2 Bolt-down Capability (Model 90)
2.1.3 Power-on Password
2.2 Override Jumper
2.3 System Features
2.3.1 Processor Boards
2.3.2 CMOS RAM and CMOS RAM Extension
2.3.3 IML, POST, and BIOS
2.3.4 Video
2.3.5 Serial Ports
2.3.6 Parallel Port
2.3.7 Diskette-Drive Controller
2.3.8 Keyboard Connector and Pointing-Device Connector
2.4 System Memory
2.4.1 Memory Requirements and Limitations
2.4.2 Types of Memory Configurations
2.4.3 Types of Error Detection
2.4.4 Memory Errors
2.5 Resolving Memory-Address Conflicts
2.5.1 Changing the Software Configuration
2.5.2 Changing the System Configuration
2.6 Selectable Drive-Startup Sequence
2.6.1 Example: Default Startup Sequence
2.6.2 Example: Changing the Startup Sequence
3.0 Option Compatibility
3.1 Drive and Diskette Compatibility
3.2 SCSI Hard Disk Drives and Devices
3.3 SCSI ID Numbers
3.3.1 Selecting a SCSI ID Priority
3.3.2 Determining the SCSI ID of an existing device
3.3.3 Setting the SCSI ID
3.3.4 Motor-Start Jumper
3.4 Terminators
3.4.1 SCSI Device Cabling and Terminators
3.4.2 SCSI Adapter Terminators
4.0 Operating Requirements
4.1 Power Supply
5.0 System Diskettes (Reference and Diagnostic)
6.0 Updating the IML Image (System Diskettes)
6.1 Installation Requirements
6.2 Backing Up the Current System Partition
6.3 Installing a New Version of the Reference Diskette
6.4 Making a New Backup Copy of the System Partition
7.0 Using ASCII Terminals (Model 95 XP 486)
7.1 ASCII Terminal Setup and Menu Selection
7.2 ASCII Terminal Configuration
7.2.1 Console Selection
7.2.2 Error Messages
7.2.3 Operations
8.0 System Error Log
8.1 Viewing the Error Log
8.2 Types of Errors Detected
8.3 Error Storage
8.4 Application
8.5 Dumping Extended Diagnostic Data Information
9.0 Miscellaneous System-Related Information
10.0 Specifications (Model 90 XP 486)
11.0 Specifications (Model 95 XP 486)
12.0 Special Tools
13.0 Handling Electro-Static Discharge (ESD) Sensitive Devices
14.0 Removals and Replacements (Model 90 XP 486)
14.1 1005 Cover
14.2 1010 Cover Lock
14.3 1015 Fan / Air Baffle
14.4 1020 Power Switch / Speaker Assembly
14.5 1025 Diskette Drive
14.6 1030 Hard Disk Drive
14.7 1035 Adapters
14.8 1040 Option Processor
14.9 1045 Memory Riser Card Bracket
14.10 1050 Memory Riser Card
14.11 1055 Power Supply
14.12 1060 Battery
14.13 1065 System Board
14.14 1070 Video Memory
15.0 Locations
15.1 Front View
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Table of Contents
¦ Copyright IBM Corp. 1990, 1992
CONTENTS - 1

15.2 Rear View
15.3 Interior View
15.4 Internal Cables
15.5 System Board
16.0 Grounds
17.0 Removals and Replacements (Model 95 XP 486)
17.1 1005 Cover and Front Bezel
17.2 1010 Cover Lock
17.3 1015 Drive Retainer and Bezels
17.4 1020 Information Panel Assembly
17.5 1025 Diskette Drive
17.6 1030 Hard Disk Drive
17.7 1035 Option Hardware Trays
17.8 1040 Adapters and Adapter Guide
17.9 1045 Option Processor
17.10 1050 Power Supply
17.11 1055 Memory Module Kit
17.12 1060 Battery
17.13 1065 System Board
17.14 1070 Adapter Retainer and Ground Assembly
17.15 1075 Rear Bezel
17.16 1080 Drive Support Structure
17.17 1085 Access Cover Fan
17.18 1090 Access Cover Fan Cable
17.19 1095 Pedestal
18.0 Locations
18.1 Front View
18.2 Rear View
18.3 Interior View
18.4 Internal Cables
18.5 System Board
19.0 Grounds
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Table of Contents
¦ Copyright IBM Corp. 1990, 1992
CONTENTS - 2

1.0 Product Description (Model 90 XP 486)
The IBM (*) Personal System/2 (*) Model 90 XP 486 computers use the IBM
Micro Channel (*) architecture. The features of the various types of the
Model 90 are:
Security
- Cover lock
- Bolt-down capability
- Power-on password
System board
- Processor board (with a connector for a cache option) (with
extended math capability)
- 80486 25-MHz
- 80486 33-MHz
- 80486 50-MHz
- Processor board (without a connector for a cache option)
- 80486SX 20-MHz (without extended math capability)
- 80487SX 20-MHz (with extended math capability)
- 80486SX 25-MHz (without extended math capability) (with a
second socket for an option processor)
- 80486DX2 25/50 25-MHz (with extended math capability) (runs
internally at 50-MHz)
- 80486 50-MHz (with extended math capability and cache)
- 64 byte complementary metal-oxide semiconductor (CMOS) random
access memory (RAM) with real-time clock and 8KB (KB equals
approximately 1 000 bytes) CMOS RAM extension
- Two memory-riser cards: one card shipped blank and one card
shipped with a minimum of 4MB (MB equals approximately 1 000 000
bytes) of random access memory (RAM). (64MB total system memory
capacity.) Minimum required memory is 2MB.
- Video
- Extended graphics array (XGA (*)) with 512KB expandable to 1MB
- Video graphics array (VGA) compatible
- Four expansion slots
- Three 32-bit expansion slots with matched-memory extension
- One 32-bit expansion slot with auxiliary-video extension
- Two serial port connectors
- Parallel port connector
- Diskette-drive controller
- Battery (to keep CMOS RAM active when power is off)
- Keyboard connector
- Pointing-device connector
Initial Machine Load (IML) support
Power supply
- Automatically switches to the 100-125 V ac or the 200-240 V ac
range
- 50 or 60 Hz
Speaker and switch assembly
101/102/122-key keyboard
Small Computer System Interface (SCSI) adapter with internal and
external connectors (occupies one of the four expansion slots)
SCSI fixed disk drive (hard disk drive)
Diskette drive.
(*) Trademark of the International Business Machines
Corporation.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Product Description (Model 90 XP 486)
¦ Copyright IBM Corp. 1990, 1992
1.0 - 1

2.0 Product Description (Model 95 XP 486)
The IBM (*) Personal System/2 (*) Model 95 XP 486 computers use the IBM
Micro Channel (*) architecture. The features of the various types of the
Model 95 are:
Security
- Cover lock
- Power-on password
System board
- Processor board (with a connector for a cache option) (with
extended math capability)
- 80486 25-MHz
- 80486 33-MHz
- 80486 50-MHz
- 80486DX2 33/66 33-MHz (runs internally at 66-MHz)
- Processor board (without a connector for a cache option)
- 80486SX 20-MHz (without extended math capability)
- 80487SX 20-MHz (with extended math capability)
- 80486SX 25-MHz (without extended math capability) (with a
second socket for an option processor)
- 80486DX2 25/50 25-MHz (with extended math capability) (runs
internally at 50-MHz)
- 80486 50-MHz (with extended math capability and cache)
- 64 byte complementary metal-oxide semiconductor (CMOS) random
access memory (RAM) with real-time clock and 8KB (KB equals
approximately 1000 bytes) CMOS RAM extension.
- Shipped with a minimum of 4MB (MB equals approximately 1 000 000
bytes) of random access memory (RAM). (64MB total system memory
capacity.) Minimum required memory is 2MB.
- Video
- Extended graphics array (XGA (*)) with 512KB expandable to 1MB
(occupies one of the eight expansion slots)
- Video graphics array (VGA) compatible
- Eight 32-bit expansion slots
- Six 32-bit expansion slots with matched-memory extension
- One 32-bit expansion slot with auxiliary-video extension
- One 32-bit expansion slot with base-video extension
- Serial-port connector
- Parallel-port connector
- Diskette-drive controller
- Battery (to keep CMOS RAM active when power is off)
- Keyboard connector
- Pointing-device connector
Initial Machine Load (IML) support
Power supply
- Switchable to the 100-125 V ac or the 200-240 V ac range
- 50 or 60 Hz
Speaker
Information panel
Small Computer System Interface (SCSI) adapter with internal and
external connectors (occupies one of the eight expansion slots)
101/102/122-key keyboard
SCSI fixed disk drive (hard disk drive)
Diskette drive.
(*) Trademark of the International Business Machines
Corporation.
Subtopics
2.1 Security
2.2 Override Jumper
2.3 System Features
2.4 System Memory
2.5 Resolving Memory-Address Conflicts
2.6 Selectable Drive-Startup Sequence
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Product Description (Model 95 XP 486)
¦ Copyright IBM Corp. 1990, 1992
2.0 - 1

2.1 Security
Subtopics
2.1.1 Cover Lock
2.1.2 Bolt-down Capability (Model 90)
2.1.3 Power-on Password
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Security
¦ Copyright IBM Corp. 1990, 1992
2.1 - 1

2.1.1 Cover Lock
Model 90: the cover lock is in the middle of the rear panel of the system
unit. The cover cannot be removed without the cover-lock key.
Model 95: the cover lock is on the front panel of the system unit. The
front bezel and side cover cannot be removed without the user's key.
If the keys for the cover lock are lost, order a new cover-lock assembly
(see "Parts" in the Hardware Maintenance Service pamphlet).
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Cover Lock
¦ Copyright IBM Corp. 1990, 1992
2.1.1 - 1

2.1.2 Bolt-down Capability (Model 90)
The bolt-down capability allows you to attach the system unit to a table
or desk.
The table or desk must have holes drilled through it, and the bolts must
be inserted from below (the table or desk) into the holes in the base of
the system unit. There are three holes 1 . The distance between the two
holes on the right side of the base is 165 mm
(6.5 in.).
Use 6 mm (0.24 in.) bolts. The length of the bolts should be 15 mm (0.60
in.) plus the thickness of the table or desk.
PICTURE 2
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Bolt-down Capability (Model 90)
¦ Copyright IBM Corp. 1990, 1992
2.1.2 - 1

2.1.3 Power-on Password
A power-on password denies access to the system by an unauthorized user
when the system is powered-on. If a power-on password is active, the
password prompt (which resembles a small key) appears on the screen each
time the system is powered-on. Access to the system occurs when the
proper password is entered.
Note: In the Unattended Start Mode, the power-on password prompt does not
appear on the screen.
To service a system with an active and unknown power-on password,
power-off the system and do the following:
1. Locate connector J10 (Model 90) or J16 (Model 95) on the system board.
2. Move the override jumper (on J10) so that it connects the center pin
and the pin on the opposite end of the connector.
3. Power-on the system.
The system detects the change and the password is erased from memory.
Leave the jumper in that position until the next time you need to reset
the password.
To reinstall a password, the user must start the system programs, select
Set features from the Main Menu, and follow the instructions.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Power-on Password
¦ Copyright IBM Corp. 1990, 1992
2.1.3 - 1

2.2 Override Jumper
The override jumper J10 (Model 90) or J16 (Model 95) on the system board
is most often used to erase a power-on password. However, the same jumper
also has multiple purposes. If you move the jumper with the system
powered-off, then power-on the system, it has the following effects on the
system:
Power-on Password: If the system has a power-on password, that password
is erased the first time the system is powered-on (after moving the
jumper).
Unattended Start Mode (server mode): If the Unattended Start Mode is
activated, then you power-off the system, move the jumper, then power-on
the system, the system bypasses that mode. After the first power-on, the
Unattended Start Mode is restored. (Power-on password is required to run
in the Unattended Start Mode).
Initial Program Load (IPL): If the startup sequence is customized via the
Selectable startup sequence utility, then you power-off the system, move
the jumper, then power-on the system, the system bypasses the customized
settings and starts with the default settings. After the first power-on,
the customized startup settings are restored.
Initial Machine Load (IML): The system loads the IML from the System
Partition by default. If the Reference Diskette is in the diskette drive,
then you move the jumper, then power on the system, the system default is
bypassed and the system loads the IML image from the Reference Diskette.
After the first power-on, the system loads the IML from the System
Partition.
To activate the override feature, move the override jumper so that it
connects the center pin and the pin on the opposite end of the connector.
The next time you power-on the system, the override is activated (for that
one power-up). Leave the override jumper in that position until the next
time you need to use the override feature.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Override Jumper
¦ Copyright IBM Corp. 1990, 1992
2.2 - 1

2.3 System Features
The major features of the system are:
Processor board
CMOS RAM
Initial Machine Load (IML)
Basic Input/Output System (BIOS)
Power-on Self-Test (POST)
Video (VGA and XGA) adapter
Serial-port connector
Parallel-port connector
Diskette-drive controller
Keyboard connector
Pointing-device connector.
Subtopics
2.3.1 Processor Boards
2.3.2 CMOS RAM and CMOS RAM Extension
2.3.3 IML, POST, and BIOS
2.3.4 Video
2.3.5 Serial Ports
2.3.6 Parallel Port
2.3.7 Diskette-Drive Controller
2.3.8 Keyboard Connector and Pointing-Device Connector
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
System Features
¦ Copyright IBM Corp. 1990, 1992
2.3 - 1

2.3.1 Processor Boards
The functions of the system can be significantly changed depending on
which processor board is installed.
All processor boards plug into the system board through two dedicated
in-line connectors. The major components on the processor board are:
System microprocessor
System clock
Direct memory access (DMA) controller
Memory controller.
Note: Some processor boards have a connector for an optional 256KB cache.
The processor boards fall into one of three types (type 1, 2 or 3)
depending on the following:
Type of DMA controller installed (16 or 32-bit)
Type of memory error detection supported (ECC or parity)
Type of memory configurations supported (interleaved or
noninterleaved).
For more information, see "System Memory" in topic 2.4.
The microprocessors used are 32-bit. They operate in the real-address or
virtual-address (protected) mode. The amount of memory supported and the
clock speed varies within each type of processor board.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Processor Boards
¦ Copyright IBM Corp. 1990, 1992
2.3.1 - 1

2.3.2 CMOS RAM and CMOS RAM Extension
CMOS RAM provides 64 bytes of storage. Fifty bytes are used to store
system configuration and security information. The real-time clock uses
the remaining 14 bytes to track the date, time, and battery level. An 8KB
CMOS RAM extension stores additional configuration and system-status
information.
The data stored in the CMOS RAM and CMOS-RAM extension is kept active by
the battery when the system is powered-off. If the stored data is lost
due to a depleted or removed battery, you can restore the data by using
one of the following methods:
If the user has a customized configuration that uses settings other
than the default, run Restore configuration from the system programs
stored on the default hard disk drive.
If default configuration settings are used, run Automatic
configuration from the system programs stored on the hard disk drive.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
CMOS RAM and CMOS RAM Extension
¦ Copyright IBM Corp. 1990, 1992
2.3.2 - 1

2.3.3 IML, POST, and BIOS
The systems use Initial Machine Load (IML) to store the power-on self-test
(POST) and Basic Input/Output System (BIOS) code. With IML, some of the
code is stored in ROM and is used for preliminary testing during power-on.
The balance of the POST and BIOS code, called the IML image, is stored in
a protected partition on the default hard disk drive. The IML image is
loaded onto the default hard disk drive when the system is manufactured.
At power-on, the first stage of POST is started from ROM. During this
stage, POST performs the following functions:
Checks the basic system-board and processor-board functions
Initializes the video function
Checks the memory subsystem
Verifies that the default hard disk drive is functioning
Verifies that the default diskette drive is functioning
Verifies that the IML image is installed in the protected partition of
the hard disk drive.
When the first stage of POST is complete, the IML image is loaded into RAM
from the System Partition on the default drive, even if the Reference
Diskette is in the diskette drive. The only time the system attempts to
load the IML image from the Reference Diskette is if any of the following
conditions exist:
An error occurred reading the System Partition
A hardware failure occurred
The override jumper was moved (prior to power-up).
The second stage of POST is started from RAM. It performs additional
tests of the hardware and initializes the system. When the second stage
of POST is complete, system control is given to the operating system.
The partition also includes the system programs and the customer and
advanced diagnostic programs. The partition is not affected when the
drive is formatted using the operating system format command.
Errors During POST: If POST detects a problem, an eight-digit error code
is displayed.
Note: On the Model 95, during POST the system displays the letters CP on
the information panel, followed by a two-digit code. The code
changes as the system progresses through POST. The "CP" codes
indicate system status. They do not mean that a failure has
occurred. For more information, see "Check Point Codes" in the
Hardware Maintenance Service pamphlet.
Replacing the Default Hard Disk Drive: If you replace the default hard
disk drive, you must recopy all of the system programs onto the
replacement hard disk drive. To recopy the programs:
1. Start the system using the customer's backup copy of the current
System Partition.
2. Select Backup/Restore system programs from the Main Menu.
3. Run the Restore the System Partition option to load the IML image, the
system programs, and the customer and advanced diagnostic programs
onto the default hard disk drive.
Notes:
1. If the user's backup copy of the System Partition is incomplete, you
will not restore the entire System Partition. If this occurs, after
you have recopied the IML image, get the option diskettes and use Copy
an option to recopy the option files onto the System Partition.
2. If the IML image is loaded onto the hard disk drive, but the
customer's operating system has not been loaded, the Insert-Diskette
icon will appear on the screen.
For information on system programs, see the Diagnostic Information for
Micro Channel Computers pamphlet.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
IML, POST, and BIOS
¦ Copyright IBM Corp. 1990, 1992
2.3.3 - 1

2.3.4 Video
On the Model 90, the video subsystem is on the system board. On the Model
95, the video subsystem is on the XGA Display Adapter/A. The video
subsystem operates in two video modes:
1. VGA compatibility mode
2. XGA compatibility mode.
The adapter comes with four video-memory modules (512KB) installed. Four
additional sockets are available for installing additional video-memory
modules (maximum video memory is 1MB). When the system is powered-on, the
graphics array is in the VGA mode. In this mode, all VGA alpha-numeric
text, and all-points-addressable (APA) graphics video modes are supported.
The maximum resolution in VGA compatibility mode is 720-by-400 picture
elements (PELS) in the text mode, and 640-by-480 PELS in the graphics
mode. A maximum of 256 colors or 64 shades of gray are supported in VGA
mode. Composite video is not supported.
The graphics array is in the XGA mode only when enabled by the DOS Adapter
Interface or video device driver (example: MS Windows (**), OS/2 (*), and
Presentation Manager (*) device drivers).
The XGA works with monochrome and color-analog direct-drive displays.
XGA supports the following:
+------------------------------------------------------------------------+
¦ Video Memory ¦ Resolution ¦ Colors ¦
+-----------------------+------------------------+-----------------------¦
¦ Four video-memory ¦ 640 x 480 ¦ 256 16 ¦
¦ modules (512KB) ¦ or ¦ ¦
¦ ¦ 1024 x 768 ¦ ¦
+-----------------------+------------------------+-----------------------¦
¦ Eight video-memory ¦ 640 x 480 ¦ 65536 256 ¦
¦ modules (1MB) ¦ or ¦ ¦
¦ ¦ 1024 x 768 ¦ ¦
+------------------------------------------------------------------------+
(*) Trademark of the International Business Machines
Corporation.
(**) Trademark of the Microsoft Corporation.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Video
¦ Copyright IBM Corp. 1990, 1992
2.3.4 - 1

2.3.5 Serial Ports
The serial ports are fully programmable and support asynchronous
communications. The 25-pin, D-shell connector provides the signals to
drive a device with a standard 25-contact RS-232 connector. The connected
device is identified by the system configuration as SERIAL 1 through
SERIAL 8. Adapters with serial ports also can be configured from SERIAL 1
to SERIAL 8. Conflicts occur with multiple communication lines if two or
more lines have the same address. Select the Set configuration option
from the system programs on the hard disk drive. Select View
Configuration to verify that no lines are addressed the same.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Serial Ports
¦ Copyright IBM Corp. 1990, 1992
2.3.5 - 1

2.3.6 Parallel Port
The parallel port allows the attachment of devices that accept eight bits
of parallel data at standard transistor-transistor logic (TTL) levels.
The port has a 25-pin, D-shell connector and is designed primarily for
printers. However, the port can be used as an input/output port for any
device or application that matches the input/output capabilities of the
port. When adapters with additional parallel ports are installed, the
system supports four devices, each addressed separately as PARALLEL 1,
PARALLEL 2, PARALLEL 3 or PARALLEL 4. Conflicts occur when using multiple
devices if two or more devices are addressed the same. Select the Set
configuration option from the system programs on the hard disk drive.
Select View configuration to verify that no lines are addressed the same.
Note: If a conflict occurs, an asterisk appears next to the conflicting
address.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Parallel Port
¦ Copyright IBM Corp. 1990, 1992
2.3.6 - 1

2.3.7 Diskette-Drive Controller
The diskette-drive controller is on the system board. The controller
connects to the diskette drives through a 34-pin cable connector (the
connector on the system board is a 40-pin cable-connector). Signals and
voltages are supplied through the diskette-drive cable that plugs into the
connector. On the Model 90, these signals and voltages can operate a
maximum of three devices (one can be a 5.25-inch device). On the Model
95, these signals and voltages also can operate a maximum of three devices
(one can be a 5.25-inch device).
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Diskette-Drive Controller
¦ Copyright IBM Corp. 1990, 1992
2.3.7 - 1