Commodore 64 User manual

A Pocket Handbook
for the Commodore 64

A Pocket Handbook
for the
Commodore 64
Peter Gerrard
&
Danny Doyle
Duckworth

Second impression April 1984
First published in December 1983 by
Gerald Duck orth & Co. Ltd.
The Old Piano Factory
43 Gloucester Crescent, London NW1
© 1983 by Peter Gerrard
All rights reserved. No part of this publication
may be reproduced, stored in a retrieval system,
or transmitted, in any form or by any means,
electronic, mechanical, photocopying, recording
or other ise, ithout the prior permission of the
publisher.
ISBN 0 7156 1787 7
British Library Cataloguing in Publication Data
Gerrard, Peter
A pocket handbook for the Commodore 64.
1 . Commodore 64 (Computer)
I . Title
001.64' QA76.8.C64
ISBN 0-7156-1787-7
Printed in Great Britain by
Red ood Burn Ltd., Tro bridge
and bound by Pegasus Bookbinding, Melksham

Contents
Preface 6
ASCII tables 7
Basic key ords 9
Basic error messages 12
Colour memory 14
Conversion tables 15
Disk commands 19
Disk error messages 21
Disk formats 26
Extramon listing 35
Flo charting 40
Hex/Dec convertor 42
Hyperbolic functions 43
Memory maps 44
Memory architecture 51
M/C instruction set 54
M/C mnemonics 74
Po ers tables 76
Cartridge slot 77
Joystick slot 78
RS232 standards 79
Centronics standards 86
Other output 87
Screen memory 89
Sound chip registers 90
Musical notes values 91
Sprite memory diagram 93
Index 95

Preface
This book is a collection of relevant facts and figures about
your Commodore 64 computer.
As ell as including full memory maps, microprocessor
instruction set, computer glossary, interface tables, disk for
mats, Basic commands, input/output tables, memory
architecture, and much more, this conveniently sized book
tells you, at a glance, any important fact you need to kno
hen programming and using your computer.
We've tried to include as much relevant material as possible
in as small a space as possible. As a result, the majority of this
book is simply facts and figures: one day e might rite a
book ith ords in it!
We'd like to thank Jim Butterfield ( ithout hom...) for
getting the hole Commodore scene rolling in his o n
inimitable style, anyone ho's given us any help, advice and
information in compiling this book, the Ne Inn in Ga cott
for providing excellent pints of Marston ales in times of stress,
and finally our ives. Penny and Beryl, for putting up ith us.
P.G. and D.D.
6

ASC tables
Standard ASCII characters (7-bit code)
01 2 3 4 5 67
MS
LS 000 001 010 Oil 100 101 no 111
00000 NUL LE SP 0 @ P -P
10001 SOH C1 11AQaq
20010 STX C2 •• 2 B R b r
30011 ETX C3 £ 3 C Sc s
40100 EOT C4 $ 4 Td t
50101 ENQ NAK 7. 5 E U e u
60110 ACK SYN &6FVfV
70111 BEL ETB 7 G ugw
81000 BS CAN (8H X hX
91001 HT EM ) 9IY i Y
A1010 LF SUB * : Jzjz
B1011 VT ESC +5Kck
C1100 FF FS *<L 1
1101 CR GS =Mm
E1110 SO RS _> N n
F
+
----
m i SI US /70o EL
The ASCII symbols.
NUL -Null LE -ata Link Escape
SOH - Start of Heading C -evice Control
STX -Start of Text NAK -Negative Acknowledge
ETX - End of Text SYN -Synchronous Idle
EOT -End of Transmission ETB -End of Transmission Block
ENQ -Enquiry CAN -Cancel
ACK -Acknowledge EM -End of Medium
BEL -Bell (audible alert) SUB -Substitute
BS -Backspace ESC -Escape
HT -Horizontal Tabulation FS - File Separator
LF - Line Feed GS -Group Separator
VT -Vertical Tabulation RS -Record Separator
FF - Form Feed US -Unit Separator
CR -Carriage Return SP -Space (Blank)
SO - Shift Out EL -elete
SI -Shift In
7

Keyboard CNTL Sequences
NUL -CNTL 1LE -CNTL P
SOH -CNTL A C1/2/3/4 - CNTL Q/R/S/T
STX -CNTL B NAK -CNTL U
ETX -CNTL C SYN -CNTL V
EOT -CNTL ETB -CNTL W
ENQ -CNTL E CAN -CNTL X
ACK -CNTL FEN -CNTL Y
BEL -CNTL G SUB -CNTL Z
BS -CNTL H/BS ESC -ESC
HT -CNTL I/TAB FS -CNTL BACKSLASH
LF -CNTL J/LF GS -CNTL
VT -CNTL KRS -CNTL =
FF -CNTL L US -CNTL -
CR -CNTL M/CR SP -Space
SO -CNTL N SI -CNTL 0
8

Basic keywords
BASIC Commands
Command Format
ABS
AN
ASC
ATN
CHR*
CLOSE
CLR
CM
CONT
COS
ATA
EF FN
IM
EN
EXP
FN
FOR
FRE
GET
GET£
GOSUB
GOTO
IF
INPUT
INPUTE
I NT
LEFT*
LEN
LET
LIST
LOA
LOG
MI *
NEW
NEXT
NOT
ON
OPEN
OR
PEEK
POKE
ABS <<expression >)
<expression) AN <expression>
ASC <<string>)
ATN(< number >)
CHR* <<number>)
CLOSE <file number>
CLR
CM <file number> L,string3
CONT
COS(< number >)
ATA <list of constants>
EF FN<name>(<variable>) * <expression>
IM <variable>(<subscripts>)C,
<variable>(<subscripts>)... 3
EN
EXP(<number >)
FN< number >(<number >)
FOR <variable> = <start> TO <limit> CSTEP
<increment)
FRE(<dummy>)
GET <variable list>
GETE <-file number >,< vari abl e list>
GOSUB <1ine number >
GOTO <line number>
IF <expression> THEN <line number>
IF <expression> GOTO <line number>
IF <expression> THEN <statement>
INPUT C"<prompt>"3; <variable list>
INPUT£<*file number>,<variable list>
INT(< numeric >)
LEFT * < < string >,<integer >)
LEN(< string >)
LET <variable> = <expression>
LIST CC<first-line>3-C<last-1ine>33
LOA C"<fi1e-name>"3 C,< device > 3
LOG(< numeric >)
MI *(<string>,<numeric-1>C ,<numeric-2>3)
NEW
NEXT C<counter>3[,<counter>3...
NOT < ex pression >
ON <variable> GOTO/GOSUB <1ine-number>
C,<1ine-number > 3 -.-
OPEN <fi1e-number>,C<device>3L,<address>3
C,"<file-name>C,<type>3C,<mode>3M3
<operand> OR <operand>
PEEK(< numeric >)
POKE <location>,<value>
9

F'OS
PRINT
PRINT£
P O S (<du mmy>)
PRINT [<variable>][<1/ ] X v a r i a b l e > ]
--
PRINTE <-fi 1 e-number> C t<variable> 3
C < , /; > <variab1e > 3...
REA
REM
RESTORE
RETURN
RIGHT*
RN
RUN
SAVE
REA <variable- C ,<variable>3...
REM [<remark>3
RESTORE
RETURN
RIGHT*(< string >,< numeric>)
R N (< numeric >)
RUN Cline number!
SAVE C "<-f i 1 e-name>" 3 C , <devi ce-number >3
SGN
SIN
SPC
SQR
STATUS
STOP
STR*
SYS
TAB
TAN
TIME
TIME*
USR
VAL
VERIFY
WAIT
C ,<address>3
SGN <<numeric>)
SIN(<numeric>>
S P C (< numeric >)
S Q R (< NUMERIC >)
ST
STOP
S T R * (<numeric>)
SYS (memory location>
T A B (< numeric>)
T A N (< numeric >)
TI
TI*
U S R (< numeric >)
VAL <<string>>
VERIFY
WAIT <1ocation>,<mask-1>C,<mask—2>3
C3 indicates optional.
<> indicates mandatory.
() indicates brackets required.
10

ARITHMETIC OPERATORS
SYMBOL 3 EXAMPLE 3 PURPOSE 3
-310 X = Y 3 ASSIGNS VALUE TO VARIABLE. 3
33 3
/3 10 X = Y / Z 3 IVISION. 3
333
*3 10 X = Y * Z 3 MULTIPLICATION. 3
333
-i- 3 io X = Y + Z 3 A ITION. 3
333
-3io X = Y - Z 3 SUBTRACTION. 3
333
=310 IF X = Y THEN 3TEST FOR EQUALITY. 3
333
<> 3 10 IF X < > Y THEN 3TEST FOR INEQUALITY. 3
333
<3 IO IF X < Y THEN 3 TEST FOR LESS THAN. 3
333
> 3 10 IF X > Y THEN 3TEST FOR GREATER THAN. 3
333
< = 310 IF X <= Y THEN 3 TEST FOR LESS THAN OR EQUAL TO. 3
333
>= 310 IF X >= Y THEN 3 TEST FOR GREATER THAN OR EQUAL TO 3
333
AN 3 IO IF X AN Y THEN 3 LOGICAL AN . 3
333
OR 3IO IF X OR Y THEN 3 LOGICAL OR. 3
333
NOT 3IO IF NOT X THEN 3 LOGICAL NEGATION. 3
333
C 3 310 PRINT XC3Y 3EXPONENTIATION. 3
ARITHMETIC FUNCTIONS
FUNCTION 3EXAMPLE 3ESCRIPTION 3
ABS 310 z=ABS(X) 3RETURNS MAGNITU E OF ARGUMENT 3
33IRRESPECTIVE OF SIGN. 3
3 3 3
ATN 310 z=ATN < X) 3RETURNS ARCTANGENT OF ARGUMENT. 3
33Z GIVEN I RA IANS. 3
333
COS 310 z=COS < X) 3RETURNS COSINE OF ARGUMENT. 3
33X MUST BE IN RA IANS. 3
333
EXP 310 z=EXP(X) 3RETURNS MATHEMATICAL CONSTANT 'E' 3
33RAISE TO POWER OF X. 3
3 3 3
INT 310 z=INT(X) 3RETURNS INTEGER PART OF X. 3
333
LOG 310 z=LOG(X) 3RETURNS NATURAL LOG OF ARGUMENT. 3
3 3 X MUST BE GREATER OR EQUAL TO 0. 3
3 3 3
RN 310 z=RN (X) 3 RETURNS RAN OM NUMBER BETWEEN 3
33ZERO AN ONE. 3
333
SGN 3 10 z=SGN(X) 3 RETURNS MATHEMATICAL SIGN OF 3
3 3 ARGUMENT. 3
3 3 3
SQR 3 10 z=SQR(X) 3RETURNS SQUARE ROOT OF ARGUMENT. 3
3 3 3
TAN 3 IO z*TAN(X) 3 RETURNS TANGENT OF ARGUMENT. 3
3 3 X MUST BE IN RA IANS. 3
11

Basic error messages
BAD DATA String data as received from an open file, but the pro
gram as expecting numeric data.
BAD SUBSCR PT The program as trying to reference an elem ent of
an array hose num ber is outside of the range specified in the DIM
statement.
CAN'T CONT NUE The CONT comm and ill not ork, either because
the program as never RUN, there has been an error, or a line has
been edited.
DEV CE NOT PRESENT The required I/O device as not available for
an OPEN, CLOSE, CMD, PRINT#, INPUT#, or GET#.
D V S ON BY ZERO Division by zero is a m athem atical oddity and not
allo ed.
EXTRA GNORED Too many items of data ere typed in response to
an INPUT statem ent. Only the first fe items ere accepted.
F LE NOT FOUND If you ere looking for a file on tape, and END-OF-
TAPE m arker as found. If you ere looking on disk, no file ith that
name exists.
F LE NOT OPEN The file specified in a CLOSE, CMD, PRINT#, INPUT#,
or GET#, must first be OPENed.
F LE OPEN An attem pt as made to open a file using the num ber of
an already open file.
FORMULA TOO COMPLEX The string expression being evaluated
should be split into at least t o parts for the system to ork ith.
LLEGAL D RECT The INPUT statem ent can only be used ithin a pro
gram , and not in direct mode.
LLEGAL QUANT TY A num ber used as the argum ent of a function or
statem ent is out of the allo able range.
LOAD There is a problem ith the program on tape.
NEXT W THOUT FOR This is caused by either incorrectly nesting loops
or having a variable name in a NEXT statement that doesn't correspond
ith one in a FOR statement.
NOT NPUT F LE An attem pt as m ade to INPUT or GET data from a
file hich as specified to be for output only.
NOT OUTPUT F LE An attem pt as made to PRINT data to a file hich
as specified as input only.
OUT OF DATA A READ statem ent as executed but there is no data
left unREAD in a DATA statem ent.
12

OUT OF MEMORY There is no more RAM available for program or
variables. This may also occur hen too many FOR loops have been
nested, or hen there are too many GOSUBs in effect.
OVERFLOW The result of a com putation is larger than the largest
num ber allo ed, hich is 1.70141884E + 38.
RED M'D ARRAY An array may only be DIMensioned once. If an array
variable is used before that array is DIM 'd, an autom atic DIM operation
is perform ed on that array setting the number of elements to ten, and
any subsequent DIMs ill cause this error.
REDO FROM START Character data as typed in during an INPUT
statement hen numeric data as expected. Just re-type the entry so
that it is correct, and the program ill continue by itself.
RETURN W THOUT GOSUB A RETURN statem ent as encountered,
and no GOSUB command has been issued.
STR NG TOO LONG A string can contain up to 255 characters.
7SYNTAX ERROR A statem ent is unrecognizable by the Commodore
64. A missing or extra parenthesis, misspelled key ords, etc.
TYPE M SMATCH This error occurs hen a num ber is used in place of a
string, or vice-versa.
UNDEF'D FUNCT ON A user defined function as referenced, but it
has never been defined using the DEF FN statement.
UNDEF'D STATEMENT An attem pt as m ade to GOTO or GOSUB or
RUN a line number that doesn't exist.
VER FY The program on tape or disk does not match the program cur
rently in m emory.
13

Colour memory
55296 -
55336
55376
55416
55456
55496
55536
55576
55616
55656
55696
55736
55776
55816
55856
55896
55936
55976
56016
56056
56096
56136
56176
56216
56256
COLUMN
20
ft
4—i—I-
-U+.
55335
I
t
56295
14
ROW

Conversion tables
Co d* C on versio n T ab le
6502 Poke
ec Oct Hex Instruction 1 2 CHR* Asc Token Binary
0OOO OO BRK e•NUL OOOO OOOO
1 OOl Ol ORA (Ind,X) A a SOH OOOO OOOl
2 002 02 -B b STX OOOO OOIO
3 003 03 -C c ETX OOOO OOll
4004 04 -d EOT OOOO OlOO
5 005 05 ORA 0-Page E e ENQ OOOO OlOl
6006 06 ASL 0-Page FfACK OOOO OHO
7007 07 -GgBEL OOOO O U l
8 010 08 PHP H h BS OOOO lOOO
9 Oil 09 ORA Immediate IiHT OOOO lOOl
10 012 OA ASL Accum. JjLF OOOO 1010
11 013 OB -K k VT OOOO 1011
12 014 OC -L1FF OOOO noo
13 015 O ORA Absolute M m CR OOOO 1101
14 016 OE ASL Absolute N n SO OOOO m o
15 017 OF -0oSI OOOO 1111
16 020 10 BPL P PLE 0001 OOOO
17 021 11 ORA (Ind),YQqCRSR N C 1 OOOl OOOl
18 022 12 -R r RVS ON C2 OOOl 0010
19 023 13 -SsHOME C3 0001 0011
20 024 14 -T t EL C4 OOOl OlOO
21 025 15 ORA O-Page,X U uNAK OOOl 0101
22 026 16 ASL 0-Page,X V VSYN OOOl 01 io
23 027 17 -wwETB OOOl 0111
24 030 18 CLC XCAN OOOl 1000
25 031 19 ORA Abs,Y YyEM OOOl 1001
26 032 1A -zzSUB OOOl 1010
27 033 IB -[CESC OOOl 1011
28 034 1C -FS OOOl n o o
29 035 I ORA Abs, X ]IGS OOOl HOI
30 036 IE ASL Abs, X RS OOOl m o
31 037 IF -US OOOl 1111
Code Conversion Table
6502 Poke CHR* Std
ec Oct Hex Instruction ULU L Asc Token Binary
32 040 20 JSR SPC SPC SPC SPC SPC OOIO OOOO
33 041 21 AN <Ind,X) OOIO OOOl
34 042 22 - •• •• " •• MOOIO OOIO
35 043 23 -£££ £ £OOIO OOll
36 044 24 BIT 0-Page *4* * * 0010 OlOO
37 045 25 AN 0-Page X 7. X X XOOIO 0101
38 046 26 ROL 0-Page & li & 6 6 OOIO 0110
39 047 27 -OOIO 0111
40 050 28 PLP ( < < ( ( 0010 lOOO
41 051 29 AN Immediate ) ) ) ) ) OOIO lOOl
42 052 2A ROL Accum. * « *« * OOIO ioio
43 053 2B -+++OOIO 1011
44 054 2C BIT Absolute f f OOIO n o o
45 055 2 AN Absolute - - - - -OOIO HOI
46 056 2E ROL Absolute . . . . . OOIO 1110
47 057 2F -/ / // / OOIO 1111
48 060 30 BMI 0 0 0 0 00011 OOOO
49 061 31 AN (Ind), Y 1 1 1 1 1 OOll OOOl
50 062 32 -2 2 2 2 2OOll 0010
51 063 33 -3 3 3 3 3OOll OOll
52 064 34 -44 4 4 4OOll OlOO
53 065 35 AN 0-PageyX 5 5 5 5 5OOll 0101
54 066 36 ROL O—Page,X 66 6 6 6OOll OHO
55 067 37 -7 7 7 7 7 OOll 0111
56 070 38 SEC 8 8 8 8 8 OOll lOOO
57 071 39 AN Abs,Y 9 9 9 9 9 OOll 1001
58 072 3A -:si : :OOll 1010
59 073 3B -;1); ; OOll 1011
60 074 3C -< < < < < OOll 1100
61 075 3 AN Abs,X a- • aOOll 1101
62 076 3E ROL Abs,X > > > > > OOll m o
63 077 3F -? ? ? 77OOll 1111
15

Code Conversion Table
Code Conversion Table
177

Code Conversion Table
6502 Poke
ec □ct Hex Instruction 1 2 CHR* Asc Token Binary
l
+
l 1 l 1 1 1 1 l
1
+
1 1
l l l
+
1 1 l l 1 1
+
1 1 1
+
1
128 200 80 -EN 1OUO 0000
129 201 81 STA (Ind,X) FOR 1000 0001
130 202 82 -NEXT 1000 0010
131 203 83 -ATA 1000 0011
132 204 84 STY 0-Page INPUT C 1000 0100
133 205 85 STA 0-Page INPUT 1000 0101
134 206 86 STX 0-Page IM 1000 01 10
135 207 87 -REA 1000 0111
136 210 88 EY LET 1000 1000
137 21 1 89 -GOTO 1000 1001
138 212 BA TXA RUN 1000 1010
139 213 8B -IF 1 ooo 101 1
140 214 8C STY Absolute RESTORE 1000 1 100
141 215 8 STA Absolute GOSUB 1000 1 101
142 216 8E STX Absolute RETURN 1000 1 1 10
143 217 8F -REM 1 ooo 1111
144 220 90 BCC STOP 1001 0000
145 221 91 STA (Ind) ,Y ON 1001 OOOl
146 222 92 -WAIT 1001 0010
147 223 93 -LOA 1001 0011
148 224 94 STY 0-Page,X SAVE 1001 0100
149 225 95 STA 0-Page,X VERIFY 1001 0101
150 226 96 STX 0-Page,Y EF 1001 0110
151 227 97 -POKE 1001 0111
152 230 98 TYA PRINTE lOOl 1000
153 231 99 STA Abs, Y PRINT 1001 1001
154 232 9A TXS CONT 1001 1010
155 233 9B -LIST 1001 101 1
156 234 9C -CLR 1001 1100
157 235 9 STA Abs , X CM 1001 1101
158 236 9E -SYS 1001 1110
159 237 9F -OPEN lOOl m i
160 240 AO L Y Immediate CLOSE 1010 0000
161 241 A1 L A (Ind,X) GET 1010 OOOl
162 242 A2 L X Immediate NEW 1010 0010
163 243 A3 -TAB ( 1010 0011
164 244 A4 L Y 0-Page TO 1010 0100
165 245 A5 L A 0-Page FN 1010 0101
166 246 A6 L X 0-Page SPC< 1010 0110
167 247 A7 -THEN 1010 0111
168 250 A8 TAY NOT i o i o 1000
169 251 A9 L A Immediate STEP i o i o 1001
170 252 AA TAX [phone]
171 253 AB - - 1010 1011
172 254 AC L Y Absolute « 1010 1100
173 255 A L A Absolute /1010 1101
174 256 AE L X Absolute 1010 1110
175 257 AF -AN 1010 n i l
176 260 BO BCS OR 1011 0000
177 261 B1 L A (Ind) ,Y > 101 1 OOOl
178 262 B2 - = 1011 0010
179 263 B3 -<1011 0011
180 264 B4 L Y 0-Page,X SGN 1011 0100
181 265 B5 L A 0-Page,X I NT i o n 0101
182 266 B6 L X 0-Page,Y ABS 1011 0110
183 267 B7 -USR 1011 0111
184 270 B8 CLV FRE 1011 1000
185 271 B9 L A Abs, Y POS 1011 1001
186 272 BA TSX SQR 1011 1010
187 273 BB -RN 1011 1011
188 274 BC L Y Abs, X LOG 1011 1100
189 275 B L A Abs, X EXP 1011 1101
190 276 BE L X Abs, Y COS 1011 1110
191 277 BF -SIN 1011 n i l
192 300 CO CPY Immediate TAN 11O0 0000
193 301 Cl CMP (Ind,X) ATN 1100 OOOl
194 302 C2 -PEEK 1100 0010
195 303 C3 -LEN 1100 0011
196 304 C4 CPY 0-Page STR* 1100 0100
197 305 C5 CMP 0-Page VAL 1100 0101
198 306 C6 EC 0-Page ASC 1100 0110
199 307 C7 -CHR* 1100 0111
200 310 C8 I NY LEFT* 1100 1000
201 311 C9 CMP Immediate RIGHT* 1100 1001
202 312 CA EX MI * 1100 1010
203 313 CB -1100 1011
17

Code C o nv e rsio n T ab le
6502
Instruction
ec Oct Hex Poke 1 2 CHR* Asc Token Binary
204 314 CC CPY Absolute H O O 1100
205 315 C CMP Absolute H O O 1101
206 316 CE EC Absolute 1100 1110
207 317 CF -1100 n i l
208 320 O BNE 1101 oooo
209 321 1 CMP (Ind) , Y 1101 oooi
210 322 2 -1101 0010
211 323 3 -1101 0011
212 324 4 -1101 OlOO
213 325 5 CMP 0-Page,X H O I OlOl
214 326 6 EC 0-Page,X 1101 o n o
215 327 7 -1101 0111
216 330 8 CL 1101 1 0 0 0
217 331 9 CMP Abs, Y 1101 1 0 0 1
218 332 A -1101 1010
219 333 B -1101 1011
220 334 C - 1101 1100
221 335 CMP Abs, X 1101 1101
222 336 E EC Abs, X 1101 1110
223 337 F -1101 n i l
224 340 EO CPX Immediate 1110 0000
225 341 El SBC (Ind,X) 1110 OOOI
226 342 E2 -1110 OOIO
227 343 E3 -1110 0011
228 344 E4 CPX 0-Page 1110 0100
229 345 E5 SBX 0-Page 1110 0101
230 346 E6 INC 0-Page 1110 ono
231 347 E7 - 1110 0111
232 350 E8 I NX 1110 1000
233 351 E9 SBC Immediate 1110 1001
234 352 EA NOP 1110 1010
235 353 EB -1110 1011
236 354 EC CPX Absolute 1110 1100
237 355 E SBC Absolute 1110 1101
238 356 EE INC Absolute 1110 1110
239 357 EF - 1110 nil
240 360 FO BEQ 1111 oooo
241 361 FI SBC (Ind) ,Y 1111 0001
242 362 F2 -1111 0010
243 363 F3 -1111 0011
244 364 F4 -1111 OlOO
245 365 F5 SBC O-Page,X 1111 0101
246 366 F6 INC 0-Page,X 1111 ono
247 367 F7 -m i 0111
248 370 F8 SE ini lOOO
249 371 F9 SBC Abs, Y nil lOOl
250 372 FA -nil 1010
251 373 FB -nil 1011
252 374 FC -nil noo
253 375 F SBC Abs, X n i l 1101
254 376 FE INC Abs, X n i l 1110
255 377 FF -n i l n i l
18