Archimedes Operating System

320 Pages·2009·7.47 MB·English

Archimedes Operating System
A Dabhand Guide
Alex and Nic van Someren
DABS
PRESS
For Alice and Carol
Archimedes Operating System:
A Dabhand Guide
© Alex and Nic van Someren
ISBN 1-870336-48-8
First edition, third impression June 1991
Editor: Bruce Smith
Proofreading: Syd Day
Typesetting: Bruce Smith
Cover: Clare Atherton
All Trademarks and Registered Trademarks are hereby acknowledged. Within this
Reference Guide the term BBC refers to the British Broadcasting Corporation.
All rights reserved. No part of this book (except brief passages quoted for critical
purposes) or any of the computer programs to which it relates may be reproduced
or translated in any form, by any means mechanical electronic or otherwise
without the prior written consent of the copyright holder.
Disclaimer: Because neither Dabs Press nor the authors have any control over the
way in which the contents of this book are used, no warranty is given or should be
implied as to the suitability of the advice or programs for any given application. No
liability can be accepted for any consequential loss or damage, however caused,
arising as a result of using the programs or advice printed in this book.
Published by Dabs Press, PO Box 48, Prestwich, Manchester M25 7HN.
Tel. [phone] Fax. [phone]
Typeset in 10 on llpt Palatino by Dabs Press using the Acornsoft VIEW
wordprocessor, MacAuthor, Apple Macintosh SE and LaserWriter II NT.
Printed and bound in the UK by BPCC Wheaton, Exeter, Devon EX2 8RP
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Contents
Introduction 13
Listing and Appendicies 13
What this Book is Not About 14
1: RISC Technology 15
The History of RISC 15
RISC and the Archimedes 16
The ARM 17
The MEMC Memory Controller 18
The VIDC Video Controller 18
The IOC Input/Output Controller 18
Conclusion 19
2: The ARM Instruction Set 20
The Programmer's Model 20
R15: The Program Counter 20
Conditional Execution 22
ARM Assembler Command Syntax 24
Shifted Operands 24
Brannch Instructions: B, BL 25
Arithmetic & Logical Instructions 26
Comparison Instructions 27
Multiplication Instructions 27
Single Register Load and Store Instructions 29
Multiple Register Load/Store Instructions 31
Softv/are Interrupts 32
3: The BASIC V Assembler 33
Basic Concepts 33
Using the Assembler 33
Variable Initialisation from BASIC 33
Archimedes Operating System
Labels in Assembler Source 34
Allocating Memory 34
Assembling Into Memory 35
Offset Assembly 35
Dealing with Forward References 35
Implementing Two-pass Assembly 36
Other Assembler Directives 37
Position Independence of Object Code 37
Executing Assembler Programs 38
Conclusion 39
4 : The Operating System 40
Communicating with the OS 40
How SWis Work 41
SWI Names 42
SWI Error Handling 43
Error Handling - Numbering 44
Error Generation 45
5 : Command Line Interpreter 47
OS_CLl Command Syntax 47
File Redirection 48
Command Line Aliases 49
OS_CLi Commands 50
^CONFIGURE 51
*ECHO 52
*ERROR 52
*EVAL 53
*FX 53
*GO 53
*COS 54
*HELP 54
*IF 55
""IGNORE 55
*KEY 56
*SET 57
*SETEVAL 58
*SETMACRO 58
*SHADOW 58
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Contents
*SHOW 59
*STATUS 59
"TIME 60
*TV 60
*UNSET 60
6 : OS_CLI Related SWIs 61
OS_CLI 61
OS_ReadVarVal 61
OS_SetVarVal 62
Marvin 62
7: Filing Systems 66
Introduction 66
Naming of Filing Systems, Files and Directories 67
Directories 67
Files on Different Filing Systems 68
Device Filing Systems 69
Ancillary File Information 70
Load and Execute Addresses 70
File Types and Date Stamping 71
Libraries and Search Paths 71
8 : The FileSwitch Module 74
FileSwitch Commands 74
*ACCESS 75
*APPEND 76
*BUILD 76
*CAT 77
*CDIR 77
*CLOSE 77
*COPY 78
''COUNT 79
*CREATE 80
*DELETE 80
*DIR 81
*DUMP 81
*ENUMDIR 82
*EX 82
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Archimedes Operating System
*EXEC 83
*INFO 83
*LCAT 83
*LEX 84
*LIB 84
*LIST 84
*LOAD 85
*OPT 86
*PRINT 86
*REMOVE 87
""RENAME 87
*RUN 88
*SAVE 88
*SETTYPE 89
*SHUT 89
"•SHUTDOWN 89
*SPOOL 90
*SPOOLON 90
*STAMP 90
*TYPE 91
*UP 91
*WIPE 92
9 : Filing System SWIs 93
OS.File (SWI &08) 93
OS.Find (SWI &0D) 100
File Path Considerations in OS_Find 101
Error Handling Extension 102
OS_GBPB (SWI &0C) 102
OS_BGet (SWI &0A) 105
OS.BPut (SWI &0B) 107
OS_Args (SWI &09) 107
OS.FSControl (SWI &29) 109
10: Modules 119
Module Related Commands 119
"MODULES 120
*RMCLEAR 120
*RMKILL 120
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Contents
*RMLOAD 121
*RMREINIT 121
*RMRUN 121
*RMTIDY 122
*UNPLUG 122
11: Writing Modules 123
Workspace Memory 123
Module Errors 123
The Format of Module Code 124
Module Start-up Code 125
Module Initialisation Code 125
Module Finalisation Code 126
Service Call Handling Code 126
Service Call Reason Codes 127
Module Title String 132
Help String 132
Help and Command Decoding Table 133
Decoding Table Layout 133
SWI Chunk Base Number 136
SWI Handling Code Offset 136
SWI Decoding Table 137
SWI Decode Code 137
A Note About SWI Translations 137
OS.Module (SWI &1E) 138
Printer Buffer Module 141
12 : Writing Applications 149
Starting Applications 149
OS_GetEnv (SWI &10) 150
Alternative Ways of Starting Applications 150
Temporarily Running Another Application 151
Top Down Applications 151
The TWIN Text Editor 152
Memory Management 153
ARM Memory Structure 153
Heap Management Software and SWls 154
OS_Heap (SWI &1D) 154
OS.ValidateAddress (SWI &3A) 156
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Archimedes Operating System
General Guidelines on Compatibility 156
The Shell Module - Source Code 157
13 : The Window Manager 161
What's On Offer? 161
The Structure of Windows 162
Window Manager Co-ordinate System 163
Programming Using the Window Manager 163
Writing a Window Manager Application 164
The Polling Loop 166
Dealing With Reason Codes 167
Closing Down the Application Window 172
Window Manager Support for Menus 172
The Structure of Menus 173
Programming Menus 173
Menus in the WimpMaze Example 175
14: The Font Manager 186
Dealing with the Font Manager 186
An Example 187
Getting Text on the Display 188
Plot Type Options 189
Conversions Between the Co-ordinate Systems 190
Conclusion 193
15: Sound Introduction 195
The Three Levels of Sound 196
Level 0 - SoundDMA 196
Level 1 - SoundChannels 196
Level 2 - SoundScheduler 197
16: Sound Star Commands 199
Level 0 Commands 199
Level 1 Commands 200
Level 2 Commands 205
17: Sound SWI Calls 207
Level 0 SWI Commands 207
Level 1 SWI Commands 215
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Contents
Level 2 SWI Commands 221
18 : The Voice Generator 226
The SVCB 226
Gate On 227
Fill 228
Gate Off 231
Update 232
Instantiate 232
Free 232
Install 232
Voice Generator Code 232
19 : Character Input/Output 238
Simple Input/Output 238
Character Input 238
Getting Hold of Single Characters 239
Whole Lines of Characters 240
Keyboard Control Functions 241
Character Output 244
Selecting Which Output Streams are to be Used 245
Selecting the VDU Stream 246
Selecting the RS423 Output Stream 246
Selecting the Printer Stream 246
Selecting the Spool File Stream 247
Character Output to the Selected Streams 248
20: Vectors 255
The Hardware Vectors 255
The Operating System Software Vectors 258
Writing Code which Intercepts Vectors 259
SWIs Which Deal with Vectors 260
21: Interrupts and Events 263
Good Behaviour 264
Switching Interrupts on and Off 264
The Main Interrupt Vector 265
Events 265
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Archimedes Operating System
22: Conversion SWIs 271
String Conversion and Decoding 271
ASCII to Binary Conversions 273
Binary to ASCII Conversions 274
23 : Miscellaneous SWIs 278
Timer Functions 278
VDU Related SWIs 281
24 : The ARM Chip Set 287
Inside MEMC 287
Virtual Memory Support 289
The MEMC Control Register 289
The Logical to Physical Translator 290
DMA Address Generators 290
Inside VIDC 291
Sound Frequency and Stereo Position 292
Inside IOC 293
25 : Floating Point Model 295
Floating Point Programmer's Model 295
The ARM Floating Point Instructions 296
Co-processor Data Transfer 297
Co-processor Register Transfer 297
Co-processor Data Operations 298
Co-processor Status Transfer Instructions 300
Conclusion 300
Appendices
A : Programs Disc 302
B : Dabhand Guides Guide 304
Index 311
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