Mitsubishi Electric LS Pro Use and care manual

apricot
HARDWARE TECHNICAL REFERENCE
MITSUBISHI ELECTRIC
LS Pro

HARDWARE TECHNICAL REFERENCE

386 and 387 are trademarks of Intel Corporation.
SCAMP is a trademark of VLSI Technology Inc.
Cyrix is a trademark of Cyrix Corporation.
National Semiconductor is a registered trademark of National Semiconductor Corporation.
Cirrus Logic is a registered trademark of Cirrus Logic Inc.
Information contained in this document is subject to change without notice and does not represent a commitment on the part of
Apricot Computers Limited. The software described in this manual is furnished under a license agreement. The software may be used
or copied only in accordance with the terms of this agreement.
It is against the law to copy any disk supplied for any purpose other than the
purchaser’s personal use.
All rights reserved; no use or disclosure without written consent.
Copyright © Apricot Computers Limited 1993
Published by
Apricot Computers Limited
3500 Parkside
Birmingham Business Park
Birmingham B37 7YS
MITSUBISHI ELECTRIC
Printed in the United Kingdom
Part no. 15050131

Chapter 1 Chapter 2 Chapter 6
Contents Chapter 3 Chapter 5
Preface
LS PRO HARDWARE TECHNICAL REFERENCE 1
Preface
The Apricot LS Pro Technical Reference Manual is intended for:
ProgrammersandengineersinvolvedinhardwareandsoftwaredesignforLSPro
computers.
Service personnel involved in fault diagnosis and repair.
All computers in the Apricot LS Pro range are covered.
The manual is divided into a number of sections and appendices as described below:
1. Introduction This is a brief overview of the Apricot LS Pro which describes the options and major
components of the system.
2. System Unit This section describes the system unit: it also includes disassembly instructions for
servicing and replacing major components of the system. It includes pinouts of the
connectors which appear on the rear of the system unit.
3. System Board This section provides an overview of the function of the system board and more
detailed descriptions of the processor and interface circuitry. Sub-sections provide a
description of each area of the board.
4. Peripheral This section describes each of the system components which attach to either the
Items systemboarde.g.floppydiskdrive,orsystemunite.g.keyboard.Alsoincludedisbrief
information on the KeyLOC card. Sub-sections describe each component.
5. Memory and This section provides information on the usage of Memory and I/O space by
I/O space the LS Pro system board, and programming information for each part of the system.
Appendices Three appendices are included:
Appendix A
This contains specifications for each component of Apricot LS Pro computers.
Appendix B
This appendix describes the differences between the revision C system board and the
revision D system board described in section 3.
Appendix C
A list of error beep codes.

Preface
ContentsChapter 1
Chapter 2
Chapter 3
Chapter 5Chapter 6
2 LS PRO HARDWARE TECHNICAL REFERENCE
Preface
Associated Publications
The following publication may be of general use to engineers and programmers.
IBM Personal Computer AT Technical Reference Manual.
The following manufacturers data sheets give information on specific devices:
Intel 80386SX
80387SX
8042 Keyboard controller
82077 Floppy disk controller
8237 DMA controller
8254 System timers
8259 Interrupt controllers
82596 Ethernet coprocessor
VLSI VL82C311 (SCAMP) AT chipset
Cyrix 486SLC
Cirrus CL-GD542X video controller
National Semiconductor NS16450 Serial communications controller
Hitachi MC146818 Real time clock

CONTENTS

Chapter 1 Chapter 2 Chapter 3 Chapter 5
Contents
Chapter 3
LS PRO HARDWARE TECHNICAL REFERENCE 1
Contents
Contents
Contents
1 INTRODUCTION
General....................................... 1/2
Variants....................................... 1/2
System unit ................................ 1/3
Keyboard.................................... 1/3
Monitors..................................... 1/4
Expansion ................................... 1/4
2SYSTEM UNIT
Introduction............................... 2/2
External layout .......................... 2/2
Internal layout ........................... 2/3
Servicing level............................ 2/3
Dismantling and re-assembly .2/3
Installing add-ons ....................2/16
System unit connectors ........2/20
3SYSTEM BOARD
3.1 Introduction ........................... 3/2
General....................................... 3/2
Description ................................ 3/4
3.2 Processor system ................ 3/5
Address and data bus
structure..................................... 3/5
Software compatibility............. 3/5
Modes of operation ................. 3/5
3.3 SCAMP ..................................... 3/6
Interrupt structure................... 3/6
Direct Memory Access ........... 3/8
System timers............................ 3/9
3.4 System memory.................3/10
General.....................................3/10
Read only memory (ROM)...3/10
Random access memory
(RAM) .......................................3/10
Real time clock (RTC) RAM 3/11
3.5 Video adapter......................3/14
General.....................................3/14
3.6 Floppy disk controller .....3/15
General.....................................3/15
Drive formats..........................3/15
3.7 Hard disk interface ...........3/16
General.....................................3/16
Interface signal descriptions.3/16
3.8 Peripherals controller .....3/17
Serial ports...............................3/17
Parallel port .............................3/18
3.9 Keyboard/mouse
controller...............................3/18
General.....................................3/18
Keyboard password security3/18
3.10 LOC Technology ...............3/19
3.11 Ethernet port ......................3/19
General.....................................3/19
3.12 Apricot Business Audio ..3/21
3.13 System board
connectors ............................3/21
Hard disk drive connectors .3/21
Floppy drive connector.........3/22
System board power
connector.................................3/22
Battery jumper........................3/22
4PERIPHERAL ITEMS
4.1 Power supply ......................... 4/2
Description ................................ 4/2
Connector ................................. 4/3
4.2 Monitors ................................... 4/3
Introduction............................... 4/3
Maintenance............................... 4/4
Video signal................................ 4/4
Apricot SVGA colour
monitor....................................... 4/4
External controls...................... 4/4
HiVision Low Emission 14"
colour.......................................... 4/6
HiVision Low Emission 17"
colour.......................................... 4/7
VGA connector ........................ 4/9
4.3 Hard disk drives ................... 4/9
Introduction............................... 4/9
Quantum ProDrive ELS .......... 4/9
Maxtor 7213A.........................4/11
Quantum ProDrive
LPS240AT.................................4/12
Quantum ProDrive
LPS525AT.................................4/13
IDE interface............................4/14

Contents
Chapter 1
Chapter 2
Chapter 3
Chapter 5 Chapter 3
2 LS PRO HARDWARE TECHNICAL REFERENCE
Contents
Contents
4.4 Floppy drive .........................4/16
Description ..............................4/16
Interface....................................4/17
4.5 Keyboard ...............................4/18
Introduction.............................4/18
Operation.................................4/19
Scan codes ...............................4/22
4.6 KeyLOC card .......................4/29
5MEMORY AND I/O USAGE
5.1 Introduction ........................... 5/2
5.2 Memory usage....................... 5/2
5.3 I/O space .................................. 5/4
DMA I/O address map............ 5/5
Interrupt controllers ............... 5/6
System timers............................ 5/6
Keyboard controller................ 5/6
Port B.......................................... 5/8
RTC RAM/NMI mask .............. 5/9
SCAMP registers ....................5/10
Apricot ports...........................5/11
Hard disk drive controller
registers....................................5/14
Serial port controller
registers....................................5/14
Ethernet controller................5/15
Business audio.........................5/17
Floppy disk controller ...........5/17
Parallel port controller .........5/18
Video DAC ..............................5/19
VGA registers .........................5/20
CL-GD542X Extension
registers....................................5/25
APPENDICES
A: Specifications
B: Revision C system board
C: Error beep codes
INDEX

Chapter 1
INTRODUCTION

Chapter 1 Chapter 6
Contents Chapter 3 Chapter 5
Introduction
Chapter 3
Chapter 1
LS PRO HARDWARE TECHNICAL REFERENCE 1/1
Contents
1 INTRODUCTION
General........................................1/2
Variants........................................1/2
System unit .................................1/3
Keyboard.....................................1/3
Monitors......................................1/3
Expansion ....................................1/4