Atari assembly language programmer's guide

346 Pages·70.02 MB·English

by  Allan E Moose, Marian J Lorenz

WESEfiI
SOFTWARE SERIES

Atari Assembly Language
Programmer's Guide
by
Allan E. Moose
Marian J. Lorenz
Weber Systems, Inc.
Chesterland, Ohio
The authors ha ve exercised due care in the preparation of this book and
the programs contained in it. The authors and the publisher make no
warranties either express or implied with regard to the information and
programs contained in this book. I n no event shall the authors or publisher be
liable for incidental or consequential damages arising out of the furnishing,
performance, or use of this book andl or its programs.
Atari 400'·, Atari 800'". Atari 800XL'·. Atari 130XE'·. and Atari TOLich Table +'. arc
trademarks or Atari Corporation. Koala Pad'· is a trademark or Koala Technologies Inc.
Published by:
Weber Systems, Inc.
8437 Mayfield Road
Chesterland, Ohio 44026
(2 I 6)729-2858
For information on translations and book distributors outside of the
United States, please contact WSI at the above address.
Atari Assembly Language Programmer's Guide
Copyright© 1986 by Allan Moose and Marian Lorenz. All rights
reserved under International and Pan-American Copyright Conventions.
Printed in the United States of America. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted in any form or by any
means, electronic, mechanical, photocopy, recording, or otherwise without
the prior written permission of the publisher.
Contents
List of Boxes 7
List of Figures 9
List of Tables 11
Preface 13
Introduction 15
1. Number Systems and Hardware 21
Decimal Number Systems 22
Binary System 22
Hexadecimal System 31
Codes 35
CPU 36
ANTIC, GTIA, POKEY, PIA 40
Overview of Memory 41
2. Overview of 6502 Instructions 45
Instructions by Function 48
Addressing Modes 55
____________________________ 63
3. Atari Graphics
TV Operation 64
ANTIC 66
Display Modes 72
Display Lists 76
Page Flipping 95
Color 97
Artifacting 106
Character Set Graphics 107
ANTIC Modes 4 and 5 _______________ 112
Player Missile Graphics 115
Coil i sions/Priority 129
4. Getting Started In Machine Language
Programming 135
Display List Interrupts 136
Program Listing Conventions ____________ _ 149
USR 151
Strings _____________________ 152
Branching ___________________ _ 161
Parameter Passing 162
Arithmetic Instructions _______________ 168
Two's Complement Arithmetic ____________ 169
AND, ORA, LSR 171
5. Sound 179
A Bit of Theory 180
Sound Hardware 189
Program Examples 197
Sixteen-Bit Music ___ _____________ _ 224
6. Advanced Techniques 229
The Vertical Blank Routines 230
Scrolling 235
Vertical Scrolling 237
Horizontal Scrolling 249
Diagonal Scrolling 257
Vertical Blank Music 260
Touch Tablet 274
Appendices 281
Summary of I nstruction Set 281
An Atari Assembler 283
An Atari Disassembler 293
Memory Map 301
ATASCII Codes 309
Instructions and Flags 319
Decimal Values for the 6502 Instructions 321
Musical Note Values 325
Index 329

List of Boxes
1 Flags 39
2 Memory Allocation 42
3 AND-OR-EOR 54
4 Program - Display List Dump 79
5 Program - Position Concepts 86
6 Program - Modified Graphics 8 87
7A Program - Mode 4 Display List 92
7B Program - Antic Mode 4 with Rocket 93
8 Program - Antic Mode 14 Display List 96
9 Program - Page Flipping 97
10 Program - POKEing in Colors 103
11 Program - Two Methods of Displaying 105
12 Program - Artifacting 107
13 Utility - BASIC Character Generator 110
14 Program - Redefined Character 113
15 Utility - Multicolored Character Generator 116
16 Program - Light Bulb Player 129
17 Program - Collision 132
18 Program - Display List Interrupt 137
19 Program - Display List Interrupt 140
20 Program - Display List Interrupt 143
21 Program - DLI Color Table 146
22 Program - USR, Strings 153
23 Notation/Listing for Machine Language 154
24 Assembly Language Listing - MOV$ 157
25 Assembly Language Listing - REDEF$ 158
25A Assembly Language Listing - REDEF$ (256 bytes) 159
7
8 Atari Assembly Language Programmer's Guide
25B Assembly Language Listing - REDEF$ (512 bytes) 160
26 Program - Moving Player 164
27 Assembly Language Listing - Moving Player 166
28 Program - Moving Missile 173
29 Assembly Language Listing - Moving Missile 174
30 Utility - Sound Effects Generator 193
31 Program - Sound Envelope 198
31A Assembly Language Listing - Sound Envelope 199
32 Program - Tremolo 201
32A Assembly Language Listing - Tremolo 202
33 Program - Vibrato 204
33A Assembly Language Listing - Vibrato 205
34 Program - Volume Only 208
34A Assembly Language Listing - Volume Only 209
35 Program - Volume with Frequency Variation 210
35A Assembly Language Listing - Box 35 211
36 Program - Waveform 214
36A Assembly Language Listing - Waveform 215
37 Utility - Music Data Generator 216
38 Program - Three Blind Mice (music) 218
38A Assembly Language Listing - Three Blind Mice 219
39 Program - Three Blind Mice with Chords 221
39A Assembly Language Listing - Three Blind Mice 222
40 Program - 16-Bit Music 225
40A Assembly Language Listing - 16-Bit Music 226
41 Machine Language Routine for VB Link 233
42 Program - Vertical Scrolling 238
42A Assembly Language Listing - CLEAR$ 240
42B Assembly Language Listing - SUB$ 241
42C Assembly Language Listing - Vertical Scroll 243
43 Program - Horizontal Scrolling 253
43A Assembly Language Listing - Horizontal Scroll 255
43B ML$ Listing 256
44 Program - Diagonal Scrolling 257
44A Assembly Language Listing - Diagonal Scrolling 259
45 Program - Finale (Scrolling/Music) 264
45A Assembly Language Listing - Finale Scrolling 267
45B Assembly Language Listing - Finale Music 272
46 Program - Reading the Atari Touch Tablet 276
46A Assembly Language Listing - Touch Tablet 277
47 Program - Atari Touch Tablet Music 278