Commodore 64 Personal Computers User Guide

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INTRODUCTION

Now that you've become more intimately involved with your Commodore 64, we want you to know that our customer support does not stop here. You may not know it, but Commodore has been in business for over 23 years.

In the 1970's we introduced the first self-contained personal computer (the PET). We have since become the leading computer company in many countries of the world.

Our ability to design and manufacture our own computer chips allows us to bring you new and better personal computers at prices way below what you'd expect for this level of technical excellence.

Commodore is committed to supporting not only you, the end user, but also the dealer you bought your computer from, magazines which publish how-to articles showing you new applications or techniques, and

. . .

importantly

. . .

software developers who produce programs on cartridge, disk and tape for use with your computer.

We encourage you to establish or join a Commodore "user club" where you can learn new techniques, exchange ideas and share discoveries.

We publish two separate magazines which contain programming tips, information on new products and ideas for computer applications.

(See Appendix N).

In North America, Commodore provides a "Commodore Information

Network" on the CompuServe Information Service

. . .

to access this network, all you need is your Commodore 64 computer and our low cost

VICMODEM telephone interface cartridge (or other compatible modem).

The following APPENDICEScontain charts, tables, and other information which help you program your Commodore 64 faster and more efficiently. They also include important information on the wide variety of Commodore products you may be interested in, and a bibliography listing of over 20 books and magazines which can help you develop your programming skills and keep you current on the latest information concerning your computer and peripherals.

106

APPENDIX A

COMMODORE 64 ACCESSORIES

AND SOFTWARE

ACCESSORIES

The Commodore

64 will

support Commodore VIC 20 storage devices

and accessories-DATASSETTE recorder, disk drive, modem, printer

so your system can expand to keep pace with changing needs.

· Datasette Recorder-This low cost tape unit enables programs and data t~ be stored on cassette tape, and played back at a later time. The data sette can also be used to play pre-written programs.

· Disk-The single disk unit uses standard SIf4-inch floppy diskettes, about the size of a 45 RPM record, to store programs and data.

Disks allow faster access to data and hold up to 170,000 characters of information each.

Disk units are "intelligent," meaning they have their own microprocessor and memory. Disks require no resources from the Commodore 64, such as using part of main memory.

· Modem-A low-cost communication device,the VICMODEM allows access to other computers over ordinary telephone lines. Users will have access to the full resources of large data bases such as The

Source, CompuServe, and Dow Jones News Retrieval Service (North

America only).

· Printer-The VIC printer produces printed copies of programs, data, or graphics.

This 30 character per second dot-matrix printer uses plain tractor feed paper and other inexpensive supplies. The

printer attaches directly to the Commodore

without any addi-

tional interfaces.

Interface Cartridges-A number of specialized cartridges will be available for the Commodore 64 to allow various standard devices such as modems, printers, controllers, and instruments to be attached to the system.

107

With a special IEEE-488 Cartridge, the Commodore 64 will support the full range of CBM peripherals including disk units and printers.

Additionally, a Z80 cartridge will allow you to run CP/M* on the

Commodore 64, giving you access to the largest base of microcomputer applications available.

SOFTWARE

Several categories of software will be offered for the Commodore 64, providing you with a wide variety of personal, entertainment, and educational applications to choose from.

BUSINESS AIDS

An Electronic Spreadsheet package will allow you to plan budgets, and perform "what in" analysis.

And with the optional graphic program, meaningful graphs may be created from the spreadsheet data.

Financial planning, such as loan amortization, will be easily handled with the Financial Planning Package.

A number of Professional Time Management programs will help manage appointments and work load.

Easy-to-use Data Base programs will allow you to keep track of

information . . . mailing lists . . . phone lists . . . inventories . . .

and organize information in a useful form.

Professional Word Processing programs will turn the Commodore 64 into a full-featured word processor.

Typing and revising memos, letters, and other text material become a breeze.

ENTERTAINMENT

The highest quality games will be available on plug-in cartridges for the Commodore 64, providing hours of enjoyment.

These programs make use of the high resolution graphics and full sound range possible with the Commodore 64.

Your Commodore 64 allows you all the fun and excitement available on MAX games because these two machines have completely compatible cartridges.

.CP/M is a registered trademark of Digital Research Inc.

108

EDUCATION

The Commodore 64 is a tutor that never tires and always gives personal attention.

Besides access to much of the vast PET educational programs, additional educational languages that will be available for the Commodore 64 include PILOT, LOGO and other key advanced packages.

109

APPENDIX B

ADVANCED

CASSETTE OPERATION

Besides saving copies of your programs on tape, the Commodore 64 can also store the values of variables and other items of data, in a group called a FilE. This allows you to store even more information than could be held in the computer's main memory at one time.

Statements used with data files are OPEN, CLOSE, PRINT#, INPUT#, and GET#.

The system variable ST (status) is used to check for tape markers.

In writing data to tape, the same concepts are used as when displaying information on the computer's screen.

But instead of PRINTing information on the screen, the information is PRINTed on tape using a variation of the PRINT command-PRINT#.

The following program illustrates how this works:

10 PRINT "WRITE-TO-TAPE-PROGRAM"

20 OPEN 1,1,1,"DATA FILE"

30 PRINT "TYPE DATA TO BE STORED OR TYPE STOP"

50 PRINT

60 INPUT "DATA",A$

70 PRINT #1, A$

S0 IF A$ <:>"STOP" THEN 50

90 PRINT

100 PRINT "CLOSING FILE"

11 0 CLOSE

The first thing that you must do is OPEN a file (in this case DATA FilE).

Line 10 handles that.

The program prompts for the data you want to save on tape in line

60. Line 70 writes what

you

typed-held in A$-onto the tape.

And the process continues.

If you type STOP, line 110 CLOSES the file.

110

To retrieve the information, rewind the tape, and try this:

19 PRINT "READ-TAPE-PROGRAt1"

29 OPEN 1,1,9,"DATA

39 PRINT "FILE OPEN"

49 PRINT

FILE"

59 INPUT#l, A$

69 PRINT A$

70 IF A$ = "STOP" THEN END

89 GOTO 49

Again, the file "DATA FILE"first must be OPENed. In line 50 the program INPUTs A$ from tape and also PRINTs A$ on the screen. Then the whole process is repeated until "STOP" is found, which ENDs the program.

A variation of GET-GET#-can also be used to read the data back from tape.

Replace lines 50-80 in the program above with:

59 GET#l, A$

69 IF A$ = "" THEN END

79 PRINT A$, ASC(A$)

89 GOTO

111

APPENDIX C

COMMODORE 64 BASIC

This manual has given you an introduction to the BASIC languageenough for you to get a feel for computer programming and some of the vocabulary involved.

This appendix gives a complete list of the rules

(SYNTAX) of Commodore 64 BASIC, along with concise descriptions.

Please experiment with these commands.

Remember, you can't do any permanent damage to the computer by just typing in programs, and the best way to learn computing is by doing.

This appendix is divided into sections according to the different types of operations in BASIC. These include:

1. Variables and Operators:

describes the different type of variables, legal variable names, and arithmetic and logical operators.

2. Commands: describes the commands used to work with programs, edit, store, and erase them.

3. Statements: describes the BASIC program statements used in numbered lines of programs.

4. Functions: describes the string, numeric, and print functions.

VARIABLES

The Commodore

64 uses three types of variables in BASIC. These are real numeric, integer numeric, and string (alphanumeric) variables.

Variable names may consist of a single letter, a letter followed by a number, or two letters.

An integer variable is specified by using the percent (%) sign after the variable name.

String variables have the dollar sign ($) after their name.

EXAMPLES

Real Variable Names: A, AS, BZ

Integer Variable Names: A%, AS%, BZ%

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String Variable Names: A$, A5$, BZ$

Arrays are lists of variables with the same name, using extra numbers to specify the element of the array. Arrays are defined using the DIM statement, and may contain floating point, integer, or string variables.

The array variable name is followed by a set of parentheses ( ) enclosing the number of variables in the list.

A(7), BZ%(11), A$(50), PT(20,20)

NOTE: There are three variable names which are reserved for use by the Commodore 64, and may not be defined by you. These variables are: ST, TI, and TI$. ST is a status variable which relates to input/output operations.

The value of ST will change if there is a problem loading a program from disk or tape.

TI and TI$ are variables which relate to the real-time clock built into the Commodore 64. The variable TI is updated every 1/60th of a second.

It starts at 0 when the computer is turned on, and is reset only by changing the value of TI$.

TI$ is a string which is constantly updated by the system. The first two characters contain the number of hours, the 3rd and 4th characters the number of minutes, and the 5th and 6th characters are the number of seconds.

This variable can be given any numeric value, and will be updated from that point.

TI$

= "101530" sets the clock to 10:15 and 30 seconds AM.

This clock is erased when the computer is turned off, and starts at zero when the system is turned back on.

OPERATORS

The arithmetic operators include the following signs:

+ Addition

Subtraction

* Multiplication

/ Division i

Raising to a power (exponentiation)

On a line containing more than one operator, there is a set order in which operations always occur. If several operations are used together

113

on the same line, the computer assigns priorities as follows: First, exponentiation.

Next, multiplication and division, and last, addition and subtraction.

You can change the order of operations by enclosing within parentheses the calculation to be performed first. Operations enclosed in parentheses will take place before other operations.

There are also operations for equalities and inequalities:

Equal To

< less Than

> Greater Than

<= less Than or Equal To

>= Greater Than or Equal To

<> Not Equal To

Finally, there are three logical operators:

AND

NOT

These are used most often to join multiple formulas in IF . . . THEN statements.

For example:

IF A

BAND C

D THEN 100 (Requires both parts to be true)

IF A

B OR C

D THEN 100 (Allows either part to be true)

COMMANDS

CONT (Continue)

This command is used to restart the execution of a program which has been stopped by either using the STOP key, a STOP statement, or an

END statement within the program.

The program will restart at the exact place from where it left off.

CO NT will not work if you have changed or added lines to the program (or even just moved the cursor), or if the program halted due to an error, or if you caused an error before trying to restart the program.

In these cases you will get a CAN'T CONTINUE ERROR.

114

LIST

The LIST command allows you to look at lines of a BASIC program in memory. You can ask for the entire program to be displayed, or only certain line numbers.

LIST

LIST 10-

LIST 10

LIST -10

LIST 10-20

Shows entire program

Shows only from line 10 until end

Shows only line 10

Shows lines from beginning until 10

Shows line from lQ to 20, inclusive

LOAD

This command is used to transfer a program from tape or disk into memory so the program can be used.

If you just type LOAD and hit

RETURN, the first program found on the cassette unit will be placed in

memory.

The

command may be followed by a program name enclosed

within quotes.

The name may then be followed by a comma and a number or numeric variable, which acts as a device number to indicate where the program is coming from.

If no device number is given, the Commodore 64 assumes device # 1, which is the cassette unit. The other device commonly used with the

LOAD command is the disk drive, which is device #8.

LOAD

LOAD "HELLO"

LOAD A$

LOAD " HELLO",8

LOAD "*",8

Reads in the next program on tape

Searches tape for program called

HELLO, and loads program, if found

Looks for program whose name is in the variable A$

Looks for program called HELLOon the disk drive

Looks for first program on disk

NEW

This command erases the entire program in memory, and also clears out any variables that may have been used.

Unless the program was

SAVEd, it is lost.

BE CAREFULWHEN YOU USE THIS COMMAND.

The NEW command can also be used as a BASIC program statement.

When the program reaches this line, the program is erased.

This is useful if you want to leave everything neat when the program is done.

115

RUN

This command causes execution of a program, once the program is loaded into memory. If there is no line number following RUN, the computer will start with the lowest line number.

If a line number is designated, the program will start executing from the specified line.

RUN

RUN 100

RUN X

Starts program at lowest line number

Starts execution at line 100

UNDEFINED STATEMENT

ERROR. You must always specify an actual line number, not a variable representation

SAVE

This command will store the program currently in memory on cassette or disk. If you ju;t type SAVEand RETURN,the program will be SAVEdon cassette.

The computer has no way of knowing if there is a program already on that tape, so be careful with your tapes or you may erase a valuable program.

If you type SAVEfollowed by a name in quotes or a string variable, the computer will give the program that name, so it can be more easily located and retrieved in the future. The name may also be followed by a device number.

After the device number, there can be a comma and a second number, either a or 1. If the second number is 1, the Commodore 64 will

put an END-OF-

TAPE

marker after your program.

This signals the

computer not to look any further on the tape if you were to give an additional LOAD command.

If you try to LOAD a program and the computer finds one of these markers, you will get a FILENOT FOUND ER-

ROR.

SAVE

SAVE "HELLO"

SAVE A$

SAVE "HELLO",8

SAVE "HELLO", 1, 1

Stores program to tape without name

Stores on tape with name HELLO

Stores on tape with name in A$

Stores on disk with name HELLO

Stores on tape with name

HELLO

and follows program with

END-OF-

TAPE marker

116

VERIFY

This command causes the computer to check the program on disk or tape against the one in memory.

This is proof that the program is actually SAVEd, in case the tape or disk is bad, or something went wrong during the SAVE. VERIFY without anything after the command causes the

Commodore 64 to check the next program on tape, regardless of name, against the program in memory.

VERIFY followed by a program name, or a string variable, will search for that program and then check. Device numbers can also be included with the verify command.

VERIFY

VERIFY "HELLO"

VERIFY "HELLO",8

Checks the next program on tape

Searches for HELLO, checks against memory

Searches for HELLO on disk, then checks

STATEMENTS

CLOSE

This command completes and closes any files used by OPEN statements. The number following CLOSE is the file number to be closed.

CLOSE 2

Only file #2 is closed

CLR

This command will erase any variables in memory, but leaves the program itself intact.

This command is automatically executed when a

RUN command is given.

CMD

CMD sends the output which normally would go to the screen (i.e.,

PRINT statements, LISTs, but not POKEs onto the screen) to another device instead. This could be a printer, or a data file on tape or disk. This device or file must be OPENed first.

The CMD command must be followed by a number or numeric variable referring to the file.

117

OPEN 1,4

CMD 1

LIST

OPENs device #4, which is the printer

All normal output now goes to printer

The program listing now goes to the printer, not the screen

To send output back to the screen,

CLOSE the file with

CLOSE1.

DATA

This statement is followed by a list of items to be used by

READ statements.

separated

Items may be numeric values or text strings, and items are by commas.

String items need not be inside quote marks unless they contain space, colon, or comma.

If two commas have nothing between them, the value will be READ as a zero for a number, or an empty string.

DATA 12, 14.5, "HELLO, MOM", 3.14, PARn

DEF FN

This command allows you to define a complex calculation as a function with a short name. In the case of a long formula that is used many times within the program, this can save time and space.

The

function name will be FN and any legal variable name (lor

2 characters long). First you must define the function using the statement

DEF

followed by the function name. Followingthe name is a set of pa-

rentheses enclosing a numeric variable.

Then follows the actual formula that you want to define, with the variable in the proper spot. You can then "call" the formula, substituting any number for the variable.

~ DEF FNA(X)

2~ PRINT FNA(7) t

12*(34.75 - X/.3)

J 7;. ;n.orted who.e

X is in the formula

For this example, the result would be 137.

DIM

When you use more than 11 elements of an array, you must execute a

DIM statement for the array. Keep in mind that the whole array takes up

118

..room

in memory, so don't create an array much larger than you'll need.

To figure the number of variables created with DIM, multiply the total number of elements in each dimension of the array.

10 DIM A$(40), B7(15), CC%(4,4,4) t t t

41 ELEMENTS 16 ELEMENTS 125 ELEMENTS

You can dimension more than 'one array in a DIM statement.

However, be careful not to dimension an array more than once.

END

When a program encounters an END statement, the program halts, as if it ran out of lines. You may use CO NT to restart the program.

FOR. . .TO. . .STEP

This statement works with the NEXT statement to repeat a section of the program a set number of times. The format is:

FOR (Var. Name)=(Start of Count) TO (End of Count) STEP(Count By)

The loop variable will be added to or subtracted from during the program.

Without any STEP specified, STEPis assumed to be 1. The start count and end count are the limits to the value of the loop variable.

10 FOR L

1 TO 10 STEP

20 PRINT L

30 NEXT L

The end of the loop value may be followed by the word STEP and another number or variable.

In this case, the value following STEP is added each time instead of 1. This allows you to count backwards, or by fractions.

GET

The GET statement allows you to get data from the keyboard, one character at a time. When GETis executed, the character that is typed is assigned to the variable.

If no character is typed, then a null (empty) character is assigned.

119

..-

GET is followed by a variable name, usually a string variable.

If a numeric variable was used and a nonnumeric key depressed, the program would halt with an error message.

The GET statement may be placed into a loop, checking for any empty result. This loop will continue until a key is hit.

1" GETA$: IF A$ ="" THEN1"

GET#

ThfW:ZEJ...# statement is used with a previously OPENed device or file, to input one character at a time from that device or file.

GET #1 ,A$

This would input one character from a data file.

GOSUB

This statement is similar to GOTO, except the computer remembers which program line it last executed before the GOSUB. When a line with a RETURN statement is encountered, the program jumps back to the statement immediately following the GOSUB. This is useful if there is a routine in your program that occurs in several parts of the program.

Instead of typing the routine over and over, execute GOSUBs each time the routine is needed.

2" GOSUB8""

GOTO OR GO TO

When astatement with the GOTO command is reached, the next line to be executed will be the one with the line number following the word

GOTO.

IF. . .THEN

IF. .

.THEN

lets the computer analyze a situation and take two possible courses of action, depending on the outcome.

If the expression is

true, the statement following

THEN

is executed. This may be any BASIC

statement.

If the expression is false, the program goes directly to the next line.

The expression being evaluated may be a variable or formula, in which case it is considered true if nonzero, and false if zero. In most cases, there is an expression involving relational operators (=, <, >,

<=, >=, <>, AND, OR, NOT).

120

:::-

10 IF X

10 THEN END

INPUT

The INPUT statement allows the program to get data from the user, assigning that data to a variable.

The program will stop, print a question mark (?) on the screen, and wait for the user to type in the answer and hit RETURN.

INPUT is followed by a variable name, or a list of variable names, separated by commas.

A message may be placed within quote marks, before the list of variable names to be INPUT. If more than one variable is to be

INPUT, they must be separated by commas when typed.

10 INPUT "PLEASE ENTER YOUR FIRST NAME ";A$

20 PRINT "ENTER YOUR CODE NUMBER"; : INPUT B

INPUT#

INPUT# is similar to INPUT, but takes data from a previously OPENed file or device.

10 INPUT#l, A

LET

LET is hardly ever used in programs, since it is optional, but the

statement is the heart

of all BASIC programs.

The variable name which is to be assigned the result of a calculation is on the left side of the equal sign, and the formula on the right.

10LETA=5

20 LETD$ = "HELLO"

NEXT

NEXTis always used in conjunction with the FOR statement.

When the program reaches a NEXTstatement, it checks the FOR statement to see if the limit of the loop has been reached.

If the loop is not finished, the loop variable is increased by the specified STEP value.

If the loop is finished, execution proceeds with the statement following

NEXT.

121

NEXT may be followed by a variable name, or list of variable names, separated by commas.

If there are no names listed, the last loop started is the one being completed.

If variables are given, they are completed in order from left to right.

10 FOR X

1 TO 100: NEXT

This command turns the GOTO and GOSUB commands into special versions of the IF statement.

ON is followed by a formula, which is evaluated.

If the result of the calculation is one, the first line on the list is executed; if the result is 2, the second line is executed, and so on. If the result is 0, negative, or larger than the list of numbers, the next line executed will be the statement following the ON statement.

10 INPUT X

20 ON X GOTO 10,20,30,40,50

OPEN

8 o

The OPEN statement allows the Commodore 64 to access devices such as the cassette recorder and disk for data, a printer, or even the screen.

OPEN is followed by a number (0-255), to which all following statements will refer. There is usually a second number after the first, which is the device number.

The device numbers are:

Screen

Cassette

Printer

Disk

Following the device number may be a third number, separated again by a comma, which is the secondary address.

In the case of the cassette, this is 0 for read, 1 for write, and 2 for write with end-of-tape marker.

In the case of the disk, the number refers to the buffer, or channel, number.

In the printer, the secondary address controls features like expanded printing. See the Commodore 64 Programmer's Reference Manual for more details.

122

10 OPEN 1,O

20 OPEN 2,1 ,0,"D"

30 OPEN 3,4

40 OPEN 4,8,15

OPENs the SCREEN as a device

OPENs the cassette for reading, file to be searched for is D

OPENs the printer

OPENs the data channel on the disk

Also see: CLOSE, CMD, GET#, INPUT#, and PRINT#, system variable

ST, and Appendix B.

POKE

POKE is always followed by two numbers, or formulas.

The first location is a memory location; the second number is a decimal value from 0 to 255, which will be placed in the memory location, replacing any previously stored value.

10 POKE 53281,0

20 5=4096* 13

30 POKE 5+29,8

PRINT

The PRINT statement is the first one most people learn to use, bUJ there are a number of variations to be aware of. PRINT can be followed by:

Text String with quotes

Variable names

Functions

Punctuation marks

Punctuation marks are used to help format the data on the screen.

The comma divides the screen into four columns, while the semicolon suppresses all spacing.

Either mark can be the last symbol on a line.

This results in the next thing PRINTed acting as if it were a continuation of the same PRINT statement.

10 PRINT

"HElLO"

20 PRINT

"HElLO"

,A$

30 PRINT A+ B

123

4~ PRINT J;

6~ PRINT

A,B,C,D

Also see: POS, SPC and TAB functions

PRINT#

There are a few differences between this statement and PRINT.

PRINT# is followed by a number, which refers to the device or data file previously OPENed. This number is followed by a comma and a list to be printed.

The comma and semicolon have the same effect as they do in

PRINT. Please note that some devices may not work with TAB and spc.

1~~ PRINT#I,"DATA VALUES"; A%, Bl, C$

READ

READ is used to assign information from DATA statements to variables, so the information may be put to use. Care must be taken to avoid READing strings where READ is expecting a number, which will give a TYPE MISMATCH ERROR.

REM

(Remark)

REMark is a note to whomever is reading a LIST of the program.

It may explain a section of the program, or give additional instructions.

REM statements in no way affect the operation of the program, except to add to its length.

REM may be followed by any text.

RESTORE

When executed in a program, the pointer to which an item in a DATA statement will be READ next is reset to the first item in the list. This gives you the ability to re-READ the information.

RESTOREstands by itself on a line.

RETURN

This statement is always used in conjunction with GOSUB. When the program encounters a RETURN, it will go to the statement immediately following the GOSUB command.

If no GOSUB was previously issued, a

RETURN WITHOUT GOSUB ERROR will occur.

124

STOP

This statement will halt program execution. The message,

BREAK

IN

xxx will be displayed, where xxx is the line number containing STOP. The program may be restarted by using the CO NT command.

STOP is normally used in debugging a program.

SYS

SYS is followed by a decimal number or numeric value in the range

0-65535. The program will then begin executing the machine language program starting at that memory location.

This is similar to the USR function, but does not allow parameter passing.

WAIT

WAITis used to halt the program until the contents of a memory location changes in a specific way. WAITis followed by a memory location

(X) and up to two variables.

The format is:

WAIT X,Y,Z

The contents of the memory location are first exciusive-ORed with the third number, if present, and then logically ANDed with the second number.

If the result is zero, the program goes back to that memory location and checks again.

When the result is nonzero, the program continues with the next statement.

NUMERIC FUNCTIONS

ABS(X) (absolute value)

ABS returns the absolute value of the number, without its sign (+ or

-). The answer is always positive.

ATN(X) (arctangent)

Returns the angle, measured in radians, whose tangent is X.

125

COS(X) (cosine)

Returns the value of the cosine of X, where X is an angle measured in radians.

EXP(X)

Returns the value of the mathematical to the power of X.

constant

e(2.71827183)

raised

FNxx(X)

Returns the value of the user-defined function xx created in a DEF

FNxx(X) statement.

INT(X)

Returns the truncated value of X, that is, with all the decimal places to the right of the decimal point removed. The result will always be less than, or equal to, X. Thus, any negative numbers with decimal places will become the integer less than their current value.

LOG(X) (logarithm)

Will return the natural log of X. The natural log to the base e (see

EXP(X». To convert to log base 10, simply divide by LOG(10).

PEEK(X)

Used to find out contents of memory location X, in the range 0-65535, giving a result from 0-255.

PEEK is often used in conjunction with the

POKE statement.

RND(X) (random number)

RND(X) returns a random number in the range 0-1. The first random number should be generated by the formula RND(-TI) to start things off differently every time.

After this, X should be a 1 or any positive number.

If X is zero, the result will be the same random number as the last one.

126

A negative value for X will reseed the generator.

The use of the same negative number for X will result in the same sequence of "random" numbers.

The formula for generating a number between X and Y is:

N = RND(l)*(Y-X)+X where,

Y is the upper limit

X is the lower range of numbers desired.

SGN(X) (sign)

This function returns the sign (positive, negative, or zero) of X. The result will be + 1 if positive, 0 if zero, and -1 if negative.

SIN (X) (sine)

SIN(X) is the trigonometric sine function. The result will be the sine of

X, where X is an angle in radians.

SQR(X) (square root)

This function will return the square root of X, where X is a positive number or O. If X is negative, an IllEGAL QUANTITYERROR results.

TAN(X) (tangent)

The result will be the tangent of X, where X is an angle in radians.

USR(X)

When this function is used, the program jumps to a machine language program whose starting point is contained in memory locations. The parameter X is passed to the machine language program, which will return another value back to the BASIC program.

Refer to the Commodore

64 Programmer's Reference Manual for more details on this function and machine language programming.

127

STRING FUNCTIONS

ASC(X$)

This function will return the ASCII code of the first character of X$.

CHR$(X)

This is the opposite of ASC, and returns a string character whose

ASCII code is X.

LEFT$(X$,X)

Returns a string containing the leftmost X characters of $X.

LEN(X$)

Returned will be the number of characters (including spaces and other symbols) in the string X$.

MID$(X$,S,X)

This will return a string containing X characters starting from the Sth character in X$.

RIGHT$(X$,X)

Returns the rightmost X characters in X$.

STR$(X)

This will return a string which is identical to the PRINTed version of X.

VAL(X$)

This function converts X$ into a number, and is essentially the inverse operation from STR$. The string is examined from the leftmost character to the right, for as many characters as are in recognizable number format.

128

10 X

VAL("123.456")

10 X = VAL("12A13B")

10 X = VAL("RIUfij17")

10 X = VAL("-1.23.45.67")

X = 123.456

X = 12

X = fij

X = -1.23

OTHER FUNCTIONS

FRE{X)

This function returns the number of unused bytes available in memory,

regardless of the value of X. Note that FRE(X)

will

read out n negative

numbers if the number of unused bytes is over 32K.

POS{X)

This function returns the number of the column (0-39) at which the next PRINT statement will begin on the screen.

X may have any value and is not used.

SPC{X)

This is used in a

PRINT statement to skip X spaces forward.

TAB{X)

TABis also used in a PRINT statement; the next item to be PRINTed will be in column

129

APPENDIX D

ABBREVIATIONS FOR

BASIC KEYWORDS

As a time-saver when typing in programs and commands, Commodore 64 BASIC allows the user to abbreviate most keywords.

The abbreviation for PRINT is a question mark. The abbreviations for other words are made by typing the first one or two letters of the word, followed by the SHIFTed next letter of the word. If the abbreviations are used in a program line, the keyword will LISTin the full form.

Command

Abbreviation

Loolcslik.

this on screen

Command

Abbreviation

Loolcslik.

this on screen

ABS

CLR

A_B

AND

ASC

A_N

A BIIiI S

ATN

A_T

A[J

CHR$

CIIIIIIH c[]

CLOSE ClI1lDDO

CLD

C 11IIII L

Am cD

CMD

BIIiI

M cIS]

CONT

COS

C I1IDD 0

NONE cD

COS

DATA

DEF

DIM

END

EXP

E

BIIiI

ElmiIx

NONE FN

FOR

F

BIIiI

FRE

FBllDR

GET

GBIIDE

GET#

NONE

GEj

GET#

GOSUB

BID

GOTO

G BIIiI 0

IF

NONE

GO

IF

BIIiI

D[!]

DEmlE

D_I

INPUT

NONE

INPUT

DE!

INPUT#

I_N

I 0

DfJ

INT

NONE

INT

130

Command

LEFT$

LEN

Abbreviation

IDIIII

NONE

LET

L18E

LIST

LEDIIiII

LOAD

LIDIIII 0

LOG

NONE

MID$

MBIIDI

NEW NONE

NOT

NIDIIIIE

Emil

NONE

OPEN

o IIIIiI P

NONE

PEEK

POKE

POS

PRINT ?

P IIIIiI E

P BIIiI 0

NONE

PRINT#

READ

PImDR

RImDE

REM NONE

RETURNREEDIiIT

Looks this on screen

like

Command

Abbreviation

LEbJ

LEN

LO

LOG

MEJ

NEW

RIGHT$

RND

IIIIiI

BIIiI

RUN

RBllDu

SAVE

S Emil A

SGN

SIN

S IIIIiI G

SBIIDI

SPC{

slIDiIp

SQR

S BID Q

STATUS

ST

NEj

STEP

ST" E

STOP

S"T

STR$

STIIIIiI R

SYS

S IIIIiI Y

PEl

TAB(

T BID A

TAN

pO

NONE

POS

THEN

TIDIIII H

ITIME

PbJ

REI

REM

RE

RE[]

TIME$ TI$

USR ulmDs

VAL

VIIIIiIA

VERIFY

VBIIiIE

WAIT

WBIIiIA

T[]

TI$

U vI!!

vEJ wI!!

Looks like this on screen

RIZI

RGj

S

SID sl;] sO

ST

STE] sID

STQ s[]]

TAN

131

APPENDIX E

SCREEN DISPLAY CODES

The following chart lists all of the characters built into the Commodore

64 character sets. It shows which numbers should be POKEd into screen memory (locations 1024-2023) to get a desired character.

Also shown is which character corresponds to a number PEEKed from the screen.

Two character sets are available, but only one set at a time. This means that you cannot have characters from one set on the screen at the same time you have characters from the other set displayed.

The sets are switched by holding down the taneously.

Emil and

[I keys simul-

From BASIC, POKE 53272,21 will switch to upper case mode and

POKE 53272,23 switches to lower case.

Any number on the chart may also be displayed in REVERSE.The

reverse character code may be obtained by adding 128 to the values shown.

If you want to display a solid circle at location 1504, POKE the code for the circle (81) into location 1504: POKE 1504,81.

There is a corresponding memory location to control the color of each character displayed on the screen (locations 55296-56295).

To change the color of the circle to yellow (color code 7) you would POKE the corresponding memory location (55776) with the character color: POKE

55776,7.

Refer to Appendix G for the complete screen and color memory maps, along with color codes.

SCREEN CODES

SET1 SET2 POKE SET1

SET2 POKE SET1

SET2 POKE

B a b

E c d e

H f

9 h

132

SET1 SET2

POKE SET1 SET2 POKE SET1 SET2 POKE

I i

J j

10 &

[JJ

0

P k

I m n

(

)

+

42

43

44 Q

$ q

17

45 #

34

I 73

J 74

R r

T s t

21

1

49

K 75

L 76

M 77

[SJ

U u

22

2

50 V v

W w 23

4

52

X x

II Q 81

Z z

54 bJ

R 82 t

[

]

[lj

< 60

X 88

C W 87

[]]

Y 89

[J]

Z

90

P 80

63 ?

EE

91

64

36

C 67

E 69 bJ

F 70

72 OJ

H

B 66

65

133

SET 1 SETZ POKE SET 1 SET Z POKE SET 1 SETZ POKE rn

ITB

105

[] 117

[]

106 []

118

107

119 rn

108

109

110

120

121

0 0

122

111 123

100 ca

112 124

101 113

125

102 114 126

EI3

103

115 127

116

104

Codes from 128-255are reversed Images of codes 0-127.

134

APPENDIX F

ASCII AND CHR$ CODES

This appendix shows you what characters will appear if you PRINT

CHR$(X), for all possible values of X. It will also show the values obtained by typing PRINT ASq"x"), where x is any character you can type.

This is useful in evaluating the character received in a GET statement, converting upper/lower case, and printing character based commands

(like switch to upper/lower case) that could not be enclosed in quotes.

PRINTS CHR$

PRINTS

CHR$

PRINTS CHR$ PRINTS

CHR$

34 3

# 35 4 52

(

DISABlES..Cl8

"14

24 41

)

III

66 i

C 67

2 50

135

[

]

PRINTS CHR$ PRINTS

CHR$ PRINTS CHR$

PRINTS

CHR$

D 68

97 ffD

126

156

100

101

C!II

127

128

129

157

158

155

159 lID

160

74 g

102

103

130

131

132

161

162

104 f1 133

105 f3 134

163

106 f5 135 0 164

107 f7

136

108 f2 137

165

11III

166

[SJ

109 f4 138

167

110 f6 139 0

111 f8

140

112

__141

[] 170

113

1llliJ142 rn

171

116

114

115

117

118

119

143

144

[Ij

172

173

III

145

ElJ

174

146

175

147 ca

176

148

177

149

178

120

OJ 121

150

179

169

168

[I]

122

151

[]

180

B3 123 152

[]

181

124

153

[]

182

96 rn

125

[I]

154

183

136

PRINTS

CHRS PRINTS

CHR$

PRINTS CHRS

184

185

D 186

187 f!]

188

189

190

191

CODES

CODE

192-223

224-254

255

SAME AS

96-127

160-190

126

137

APPENDIX

G

SCREEN AND COLOR MEMORY MAPS

1624

1664

1704

1744

1784

1824

1864

1904

1944

1984

1024-

1064

1104

1144

1184

1224

1264

1304

1344

1384

1424

1464

1504

1544

1584

The following charts list which memory locations control placing characters on the screen, and the locations used to change individual character colors, as well as showing character color codes.

SCREENMEMORYMAP

COLUMN

20 30

10 ~

138

The actual values to POKE into a color memory location to change a character's color are: f/!

BLACK

WHITE

2 RED

CYAN

4 PURPLE

5 GREEN

6 BLUE

YellOW

ORANGE

BROWN

If/!

Light RED

11 GRAY 1

12 GRAY 2

Light GREEN

Light BLUE

GRAY 3

55856

55896

55936

55976

56016

56056

56096

56136

56176

56216

56256

55296-

55336

55376

55416

55456

55496

55536

55576

55616

55656

55696

55736

55776

55816

For example, to change the color of a character located at the upper left-hand corner of the screen to red, type: POKE 55296,2.

COLOR MEMORY MAP

COLUMN

30 39

55335

20 t

56295

139

APPENDIX H

DERIVING MATHEMATICAL FUNCTIONS

Functions that are not intrinsic to Commodore 64 BASIC may be calculated as follows:

FUNCTION

SECANT

COSECANT

COTANGENT

INVERSE SINE

INVERSE COSINE

INVERSE SECANT

INVERSE COSECANT

INVERSE COTANGENT

HYPERBOLIC SINE

HYPERBOLIC COSINE

HYPERBOLIC TANGENT

HYPERBOLIC SECANT

HYPERBOLIC COSECANT

HYPERBOLIC COTANGENT

INVERSE HYPERBOLIC SINE

INVERSE HYPERBOLIC COSINE

INVERSE HYPERBOLIC TANGENT

INVERSE HYPERBOLIC SECANT

INVERSE HYPERBOLIC COSECANT

INVERSE HYPERBOLIC COTAN-

GENT

BASIC EQUIVALENT

SEC(X)= I/COS(X)

CSC(X)= I/SIN(X)

COT(X)= I/TAN(X)

ARCSIN(X)=ATN(X/SQR(- X.X + 1»

ARCCOS(X)= -ATN(X/SQR

(-X.X

+1»

+7T/2

ARCSEC(X)=ATN(X/SQR(X.X

- 1»

ARCCSC(X)=ATN(X/SQR(X.X -1»

+(SGN(X)-I.7T/2

ARCOT(X)=ATN(X)+7T/2

SINH(X)= (EXP(X)- EXP(- X»/2

COSH(X)= (EXP(X)+ EXP(

TAN H(X)= EXP(

X»/2

X)/(EXP(x)+ EXP

(- X».2+ 1

SECH(X)= 2/(EXP(X)+ EXP(

X»

CSCH(X)= 2/(EXP(X)- EXP(- X»

COTH(X)= EXP(

X)/(EXP(X)

-EXP(-X».2+1

ARCSINH(X)= LOG(X+ SQR(X. x + 1»

ARCCOSH(X)= LOG(X+SQR(X.X -1»

ARCTANH(X)= LOG« 1+ X)/(1- X»/2

ARCSECH(X)= LOG«SQR

(-X.X+ 1)+ I/X)

ARCCSCH(X)= LOG«SGN(X). SQR

(X.X+l/x)

ARCCOTH(X)= lOG«X + 1)/(x-l »/2

'140

APPENDIX I

PINOUTS FOR INPUT/OUTPUT DEVICES

This appendix is designed to show you what connections may be made to the Commodore 64.

1) Game I/O

2) Cartridge Slot

3) Audio/Video

4) Serial I/O (Disk/Printer)

5) Modulator Output

6) Cassette

7) User Port

Control Port 1

Pin

Type

JOYAO

JOYAl

JOYA2

JOYA3

POT AY

BUTTON A'LP

+5V

GND

POT AX

Note

MAX. 50mA

1 o o

2 o o

3 o

4 o o

8 o

5 o

Control Port 2

Pin

Type

JOYBO

JOYBI

JOYB2

JOYB3

POT BY

BUTTON B

+SV

GND

POT BX

Note

MAX. SOmA

141

Cartridge Expansion Slot

TVDe

BA i5MA

GND

Type

GND

22 2120 1918171615 U 13 12 1110 9 8 7 8 5 4 3 2 1

IV XWVUTSRPNMLKJHFEOCBA

Audio/Video

SerialI/O

Type

LUMINANCE

GND

AUDIO OUT

VIDEO OUT

AUDIO IN

SERIALSRQIN

GND

SERIALATN IN/OUT

SERIALCLK IN/OUT

Type

SERIAL DATA IN/OUT

RESET

Note

142

. Type

GND

ROMH

REsEr

NMI

S 02

A1S

A14

A13

A12

All

Al0

Type

GND

+SV

IRQ

R/w

Dot Clock

I/O 1

GAME

EXROM

I/O 2

ROML

Cassette

A-I

B-2

C-3

D-4

E-S

F-6

GND

+SV

CASSETTEMOTOR

CASSETTE READ

CASSETTE WRITE

CASSETTESENSE

Type

User I/O

Type

GND

+SV

RESET

CNTI

SPI

CNT2

SP2

PC2

SER. ATN IN

9 VAC

GND

PB4

PBS

PB6

PB7

PA2

GND

FLAG2

PBO

PBI

PB2

PB3

Type

H l

Note

MAX. lOa mA

1 2 3 4 5 6 7 8 9 10 11 12

Note

ABC D E F H J K L M N

143

123458

..---.

ABC D E F

APPENDIX

J

PROGRAMS TO TRY

We've included a number of useful programs for you to try with your

Commodore 64. These programs will prove both entertaining and useful.

-~.

144

580

590

600

610

620

630

640

650

660

670

680

690

700

710

720

730

740

750

800

810

820

200

210

220

250

260

270

280

290

300

310

320

330

340

400

410

420

100

120

130

140

150

160

170

180

190

430

440

450

500

510

520

530

540

550

560

570 print"~jotto Jim butterfi~ld" input"~want instructions"i;$:ifasc(;.)=78got0250 pr nt"~try to gu~ss the mystery 5-1etter word" pr nt"~you must gu~ss only legal 5-1etter" pr nt"words, too..." pr nt"you will b~ told th~ number of matches" pr nt"(or 'jots') of your guess." pr nt"~hint: the trick is to vary slightly" pr nt" from one guess to. the next, so that" pr nt" If you guess 'batch' and get 2 jots" pr nt" you might try 'botch' or 'chart'" pr nt" for the next guess..." data bxbsf,ipcc;,dbdif,esfbe,pggbm data hpshf,ibudi,djwjm,kpmm;,lb;bl data sbkbi,mfwfm,njnjd,boofy,qjqfs data rvftu,sjwfs,qsftt,puufs,fwfou data xfbwf,fyupm,nvti;,afcsb,gjaa; data uijdl,esvol,gmppe,ujhfs,gblfs data cppui,mzjoh,trvbu,hbvaf,pxjoh data uisff,tjhiu,bymft,hsvnq,bsfob data rvbsu,dsffq,cfmdi,qsftt,tqbsl data sbebs,svsbm,tnfmm,gspxO,~Sjgu n=50 dim n$(n),z(5),y(S) for j=1ton:readn$(j):nextj t=ti t=t/1000:ift>=1thengot0440

;=rnd(-t) g=0:n$=n$(rnd(1)*n+1) print "~i have a five letter word:":ifr>Ogot0560 print "guess (with legal words)" print "and i'll tell you how many" print "'jots', or matching letters," print "you hav~ " g=g+1:input "your word",z' if len(;$)<>5thenprint"you must guess a

S-l~tt~r word!":gotoS60 v=O:h=O:m=O forj=1t05 z=asc(mid$(z',j,1»:y=asc(mid$(n$,j,1»-1:lfy=64theny=90 if;(650rz>90thenprint"that's not a word!":got0560 ifz=650rz=690rz=730rz=790rz=850rz=89thenv=v+1 ifz=ythenm=m+1 z(j)=z:y(j)=y:nextJ ifm=5got0800 ifv=00rv=5thenprint"come on..what

kind of a word is that?":got0560 for j=1t05:y=y(j) for k=lt05:ify=z(k)thenh=h+l:z(k)=0:got0700 next k next j print"DDDDDDDDDDDDDDDDDDDD",H,"JOTS" ifg(30got0560 print"i'd.better

tell you.. word was '", forj=1t05:~rintchr$(y(j»i:nextj print"'":got0810 print"you got it in onlY"ig,"guesses." input"~another word",z$ r=1:ifasc(;$)(>78gotoSOO

145

1 rem *** seQuence

2 relR

3 rem ***

I, rem *** from pet user group software exchange

5 reM ***

po box 371

6 rem *** montgomeryville, pa 18936

7 rem

50 dllR a$(26)

100 z$="abcdefghijklmnopqrstuvwxyz"

110 21$="12345678901234567890123456"

200 print"'~~enter length of string to be sequenced~"

220 Input "maximum length is 26 "~s%

230 if s%(1 or s%)26 then 200

240 s=s%

300 for i=1 to s

310 a$(i)=mid$(z$,i,l)

320 next i

400 rem randomize

420 for 1=1 to s

430 k=int(rnd(I)*s+l) string

440 t$=a$ ( I )

450 a$(

i )=a$(k)

460 a$(k )=U

470 next i

480 Qosub

595 t=O

950

600 rem reverse substring

605 t=t+l

610 input "how many to reverse ";r%

620 if r%=O goto 900

630 if r%)O and r%(=s goto 650

640 print "must be between 1 and "IS: go to 610

650 r=int(r%/2)

660 for i=1 to r

670 U=a$( i)

680 a$(i)=a$(r%-i+l)

690 a$(r%-i+l)=t$

700 next i

750 gosub 950

800 c=l: for i=2 to s

810 if a$(i»a$(i-l)

820 c=O

830 ne>:t i

840 if c=O go to 600 goto 830

850 print "~you did it in "it;" tries"

900 rem check for another game

910 input "~want to play again ";y$

920 if

930 end left$(y$,I)="y" or y$="ok" or y$="I" goto 200

950 print

960 print left$(zl$,s)

970 for 1=1 to s: print a$(i)~:next

980 print "~"

990 return

This program courtesy of Gene Deals

146

1:~0

19')

2(10

211)

22(1

23"~1

241)

.250

9(1

REM F'l At.m KE'T'E:OAF;D

10C'

110

12')

PRINT"~ ~ g ~ I U ~ ~ I ~ n I ~ ~ "

PRINT" ~ M ~ I ~ ~ ~ i ~ M I ~ ~

PR HIT" ..1~ I!J I ~J i!JI it~ I

" i!JI

I!J I I!II

I!J

1 :-::"~1

PFUNT" ~ I I I I I I I I I I I I "

141)

15')

16')

PRINT" ;:11) IR IT I','IU 1110

PRUIT":!j'-SPACE'- FOR SOLO

IP II] I;+; I.t"

OR POL','PHO~UC"

PRINT":!j'F1 ,F~'3._F5..F7'SELECTIClt~"

1(1)

PR I ~IT" :!j'F 4._

F6._

F8'1..IA' EFClRt.1~..

PRHIT"HAt'IG ()N._SETTIt~G UP FREClUEI..jC',' _ _"

S_13*41)96+1024:DIMF(26):OIMKC255)

FOR I ",\)TCI2:~ : POKE:;+ I. <) : t.jE;".:T

Fl_7040:FORI_1T026:F(27-I)_F1;+;5.8+30:F1_F1/2~C1/12):NEXT

K$="1)2W3ER5T6Y7UI900P@-*£~"

FC'PI~l TOU::N(K$> : I.::(F'f;:;C( rHO:t(Kt._

I» )-1 :NE:,:T

PRItH":J

AT =1) : DE") : SU= 15 : PE-9 : :;:; '''':;1)* 16+RE : AV=AT;+;16+0E :

~N= 16 : 1.,=0 : 1'1=1 : OC=4 : H8=256 : Z=':'

261.)

FIJR I ",')T'J2 : PCtKES+5+ I *7.. AT;+;16+0E : PCIKES+6+ I;+;7._ SU;+;16...RE

2713

POKES+2+ 1;+;7._40CII)At.10255

: POI(ES+3+ 1;+;7,4000/256: t.jE:.<:T

POKES+24,15:REM+16+64:POKES+23.7

3~30

31e

GETA$: IFA$=" "THEt.1301)

FR.F(K(ASI:::CA,'P) ),..t'1 :T-'./;+;7 :CR-S+T+4: IFFR-ZTHEH50')

321)

:325

33&.)

341)

350

361.)

:365

3713

375

3813

POI<:ES+6+T,Z :REI'1 FItHSH

POKES+5+ T ._2 :REt'1 FItH:;H

POKECR,8:POKECR,O:REM

DEC.":3US

ATT REL

FIX ClFF

POKES+T..FR-H8;+;HITCFR/HB)

PClKES+l+T..FP,'HB:REt'1

:REI1

:;ET HI

$ET LO

POKES+6+T,SV:REM

POKES+5+ T._

SET OEC/SUS

REI'1 :;ET ATT /REL

PPKECR,WV+l:FORI_1T(51)*AT:NEXT

POKECR,WY:REM PUL$E

IFP-1THENV=V+1:IFY=3THENY=1)

4 ell)

t3IJTIJ3a.)I.)

501.)

I FA$=" iiii"THEt'U'1=1 : OC=4 : GOT03CII)

51')

IFA$'-"!!!"THEHI'1=2 :IJC-~: : GOTO:3CII)

IFA$="I!I"THEt~~1=4 :OC-2 :130TO:::o)C,

53')

540

IFA$="ill"THEt.H'1=::;.

:OC=l :GOT03')')

IFA$="9"THEt~I.J-C' :.1' =16 : GOT'J:::O')

'550

560

I FA$_" JG"THEHI.I- 1 : 1.1'.,1=32: GOTO:3')O

IFA$=":i!"THEt.n.I=2 :W =64 : GOT03.:II)

570

581)

IFA$=" "THEHP=1-P:GOT0309

59(1

61.3(1

:3(.1)

:::1(1

I FA$ -":J" THE~j2'30

O(ITCI3(1(\

PRHIT"HIT A KE','"

1 C,:I.IA

FOR A I.:E','

:32a.~ PRHJTA$ :RETUF:N

NOTES:

Line 100 uses (SHIFT CLR/HOME).

(CTRL 9),(CTRL ]),(SHIFT B).

Line 150 uses (CRSR DOWN)

Line 240 uses (CRSR UP)

Line 500 uses (11)

Line 510 uses (13)

Line 520 uses (15)

Line 530 uses (17)

Line 540 uses (12)

Line 550 uses (14)

Line 560 uses (16)

Line 570 uses (18)

Line 590 uses (SHIFT CLR/HOME)

147

APPENDIX K

CONVERTING STANDARD

BASIC PROGRAMS TO

COMMODORE 64 BASIC

If. you have programs written in a BASIC other than Commodore

BASIC, some minor adjustments may be necessary before running them on the Commodore-64.

We've included some hints to make the conversion easier.

String Dimensions

Delete all statements that are used to declare the length of strings. A statement such as DIM A$(I,J), which dimensions a string array for J elements of length I, should be converted to the Commodore BASIC statement DIM A$(J).

Some BASICs use a comma or ampersand for string concatenation.

Each of these must be changed to a plus sign, which is the Commodore

BASIC operator for string concatenation.

In Commodore-64 BASIC, the MID$, RIGHT$, and LEFT$functions are used to take substrings of strings. Forms such as A$(I) to access the Ith character in A$, or A$(I,J) to take a substring of A$ from position I to J, must be changed as follows:

Other BASIC

A$(I)

A$(I,J) = X$

Commodore 64 BASIC

= LEFT$(A$,I-1)+X$+MID$(A$,I+1)

A$ = LEFT$(A$,I-1)+ X$+MID$(A$,J+ 1)

Multiple Assignments

To set Band C equal to zero, some BASICs allow statements of the form:

19) LET B=C=9)

148

Commodore

64 BASIC would interpret the second equal sign as a logical operator and set B

-1 if C

O. Instead, convert this statement to:

1!11C=0 : B=!II

Multiple Statements

Some BASICs use a backslash (\ ) to separate multiple statements on

a line. With Commodore

64 BASIC, separate all statements by a colon

(:).

MAT Functions

Programs using the MATfunctions available on some

BASICs

must be

rewritten using FOR. . .NEXT loops to execute properly.

149

APPENDIX

L

ERROR MESSAGES

This appendix contains a complete list of the error messages generated by the Commodore-64, with a description of causes.

BAD DATA

String data was received from an open file, but the program was expecting numeric data.

BAD SUBSCRIPT

The program was trying to reference an element of an array whose number is outside of the range specified in the DIM statement.

CAN'T CONTINUE

The CO NT command will not work, either because the program was never RUN, there has been an error, or a line has been edited.

DEVICE NOT PRESENT

The required I/O device was not available for an OPEN, CLOSE, CMD, PRINT#, INPUT#, or GET#.

DIVISION BY ZERO

Division by zero is a mathematical oddity and not allowed.

EXTRA IGNORED

Too many items of data were typed in response to an INPUT statement.

Only the first few items were accepted.

FILENOT FOUND

If you were looking for a file on tape, and END-OF-

TAPE marker was found.

If you were looking on disk, no file with that name exists.

FILENOT OPEN The file specified in a CLOSE, CMD, PRINT#, INPUT#, or GET#, must first be OPENed.

FILEOPEN

An attempt was made to open a file using the number of an already open file.

FORMULA TOO COMPLEX

The string expression being evaluated should be split into at least two parts for the system to work with, or a formula has too many parentheses.

ILLEGALDIRECT The INPUT statement can only be used within a program, and not in) direct mode.

ILLEGALQUANTITY

A number used as the argument of a function or statement is out of the allowable range.

150

lOAD

There is a problem with the program on tape.

NEXT WITHOUTFOR This is caused by either incorrectly nesting loops or having a variable name in a NEXTstatement that doesn't correspond with one in a FOR statement.

NOT INPUT FilE

An attempt was made to INPUT or GET data from a file which was specified to be for output only.

NOT OUTPUTFILE An attempt was made to PRINT data to a file which was specified as input only.

OUT OF DATA A READ statement was executed but there is no data left unREAD in a DATAstatement.

OUT OF MEMORY There is no more RAM available for program or variables.

This may also occur when too many FOR loops have been nested, or when there are too many GOSUBs in effect.

OVERFLOW The result of a computation is larger than the largest number allowed, which is 1.70141884E+38.

REDIM'DARRAY An array may only be DIMensioned once. If an array variable is used before that array is DIM'd, an automatic DIM operation is performed on that array setting the number of elements to ten, and any subsequent DIMs will cause this error.

REDO FROM

START Character data was typed in during an INPUT statement when numeric data was expected.

Just re-type the entry so that it is correct, and the program will continue by itself.

RETURN WITHOUT GOSUB

A RETURN statement was encountered, and no GOSUB command has been issued.

STRING TOO lONG

A string can contain up to 255 characters.

?SYNTAX ERROR A statement is unrecognizable by the Commodore

64. A missing or extra parenthesis, misspelled keywords, etc.

TYPEMISMATCH This error occurs when a number is used in place of a string, or vice-versa.

UNDEF'D FUNCTION

A user defiried function was referenced, but it has never been defined using the DEF FN statement.

UNDEF'D STATEMENT

An attempt was made to GOTO or GOSUB or

RUN a line number that doesn't exist.

VERIFY

The program on tape or disk does not match the program currently in memory.

151

APPENDIX M

MUSIC NOTE VALUES

This appendix contains a complete list of Note#, actual note, and the values to be POKEd into the HI FREQ and LOW FREQ registers of the sound chip to produce the indicated note.

MUSICAL

NOTE

OCTAVE

C-O

A-O

A#-O

B-O

C-1

C#-l

D-1

D#-l

E-1

F-1

F#-l

G-1

G#-l

A-1

A#-l

B-1

C-2

C#-O

D-O

D#-O

E-O

F-O

F#-O

G-O

G#-O

NOTE

DECIMAL

268

284

301

318

337

358

379

401

425

451

477

506

536

568

602

637

675

716

758

803

851

902

955

1012

1072

152

OSCILLATOR FREQ

HI LOW

125

163

204

246

134

187

244

102

123

145

169

195

221

250

MUSICAL NOTE

NOTE OCTAVE

A-2

A#-2

B-2

C-3

C#-3

D-3

D#-3

E-3

F-3

F#-3

G-3

G#-3

A-3

A#-3

B-3

C#-2

D-2

D#-2

E-2

F-2

F#-2

G-2

G#-2

C-4

C#-4

D-4

D#-4

E-4

F-4

F#-4

G-4

G#-4

A-4

A#-4

B-4

C-5

C#-5

DECIMAL

OSCILLATORFREQ

1804

1911

2025

2145

2273

2408

2551

2703

2864

3034

3215

3406

3608

3823

4050

4291

4547

4817

5103

5407

5728

6069

6430

6812

1136

1204

1275

1351

1432

1517

1607

1703

7217

7647

8101

8583

9094

LOW

167

119

233

225

104

247

143

218

143

239

210

195

112

180

251

152

237

195

209

239

181

156

223

165

135

134

153

MUSICAL

NOTE

OCTAVE

NOTE

100

101

102

103

104

105

106

107

112

113

114

115

116

117

118

119

120

121

122

123

C-O

C#-O

D-O

F-5

F#-5

G-5

G#-5

A-5

A#-5

6-5

C-6

C#-6

D-6

D#-6

E-6

F-6

F#-6

G-6

G#-6

A-6

A#-6

6-6

C-7

C#-7

D-7

D#-7

E-7

F-7

F#-7

G-7

G#-7

A-7

A#-7

6-7

OSCILLATOR FREQ

100

106

112

119

126

134

142

150

159

168

179

189

200

212

225

238

253

DECIMAL

30588

32407

34334

36376

38539

40830

43258

45830

48556

51443

54502

57743

61176

64814

9634

10207

10814

11457

12139

12860

13625

14435

15294

16203

17167

18188

19269

20415

21629

22915

24278

25721

27251

28871

LOW

121

115

199

124

151

191

125

131

214

139

126

250

172

243

230

143

248

162

223

193

107

190

154

Location

54293

54294

54295

54296

FILTER SETTINGS

Contents

Low cutoff frequency (0-7)

High cutoff frequency (0-255)

Resonance (bits 4-7)

Filter voice 3 (bit 2)

Filter voice 2 (bit 1)

Filter voice 1 (bit 0)

High pass (bit 6)

Bandpass (bit 5)

Low pass (bit 4)

Volume (bits 0- 3 )

155

APPENDIX

N

BIBLIOGRAPHY

Addison-Wesley

Compute

Cowboy Computing

Creative Computing

Dilithium Press

Faulk Baker Associates

Hayden Book Co.

"BASIC and the Personal Computer", Dwyer and Critchfield

"Compute's First Book of PET/CBM"

"Feed Me, I'm Your PET Computer", Carol Alexander

"looking Good with Your PET", Carol Alexander

"Teacher's swers"

PET-Plans, Quizzes, and An-

"Getting Acquainted With Your VIC 20",

T. Hartnell

"BASIC Basic-English Dictionary for the PET", lorry Noonan

"PET BASIC", Tom Rugg and Phil Feldman

"MOS Programming Manual", MOS Technology

"BASIC From the Ground Up", David E. Simon

"I Speak BASIC to My PET", Aubrey Jones, Jr.

"Library of PETSubroutines", Nick Hampshire

"PET Graphics", Nick Hampshire

"BASIC Conversions Handbook, Apple, TRS-

80, and PET", David A. Brain, Phillip R.

Oviatt, Paul J. Paquin, and Chandler P. Stone

156

Howard W. Sams

,Little, Brown & Co.

McGraw-Hili

Osborne/ McGraw-Hili

P. C. Publications

"The Howard W. Sams Crash Course in Microcomputers", louis E. Frenzel, Jr.

"Mostly BASIC: Applications for Your PET",

Howard Berenbon

"PET Interfacing", James M. Downey and Steven M. Rogers

"VIC 20 Programmer's Reference Guide", A.

Finkel, P. Higginbottom, N. Harris, and M.

Tomczyk

"Computer Games for Businesses, Schools, and Homes", J. Victor Nagigian, and William

S. Hodges

"The Computer Tutor: learning Activities for

Homes and Schools", Gary W. Orwig, University of Central Florida, and William S. Hodges

"Hands-On BASIC With a PET", Herbert D.

Peckman

"Home and Office Use of VisiCalc", D.

Castlewitz, and L. Chisauki

"PET/CBM Personal Computer Guide", Carroll

S. Donahue

"PET Fun and Games", R. Jeffries and G.

Fisher

"PET and the IEEE", A. Osborne and C.

Donahue

"Some Common BASIC Programs for the PET",

L. Poole, M. Borchers, and C. Donahue

"Osborne CP/M User Guide", Thom Hogan

"CBM Professional Computer Guide"

"The PET Personal Guide"

"The 8086 Book", Russell Rector and George

Alexy

"Beginning Self-Teaching Computer lessons"

157

Prentice-Hall

Reston Publishing Co.

"The PET Personal Computer for Beginners",

S. Dunn and V. Morgan

"PET and the IEEE488 Bus (GPIB}", Eugene

Fisher and C. W. Jensen

"PET BASIC-Training Your PET Computer",

Ramon Zamora, Wm.

F. Carrie, and B.

Allbrecht

"PET Games and Recreation", M. Ogelsby, L.

Lindsey, and D. Kunkin

"PET BASIC", Richard Huskell

"VIC Games and Recreation"

Telmas Courseware

Ratings

Total Information Services

"BASIC and the Personal Computer", T. A.

Dwyer, and M. Critchfield

"Understanding Your PET/CBM, Vol. 1, BASIC

Programming"

"Understanding Your VIC", David Schultz

Commodore Magazines provide you with the most up-to-date information for your Commodore 64. Two of the most popular publications that you should seriously consider subscribing to are:

COMMODORE-The Microcomputer

Magazine

is published bi-monthly and is available by subscription ($15.00 per year, U.S., and $25.00 per year, worldwide).

-The

Home Computer Magazine is published quarterly

and is available by subscription ($10.00 per year, U.S., and $15.00 per year worldwide).

158

APPENDIX 0

SPRITE REGISTER MAP

Dee Hex 087

0 0 SOX7

086

085 084

083 082 081 080

SOY7

SOXO SPRITE 0 X

Component

SOYO SPRITE 0 Y

Component

SIXO

SPRITE I X

SIYO SPRITE 1 Y

S1X7

3 SIY7

4 S2X7

'S2Y7

S2XO SPRITE 2 X

52 YO

SPRITE 2 Y

S3XO

SPRITE 3 X

6 !S3X7

!s3Y7

S4X7

S3YO SPRITE 3 Y

S4XO

SPRITE 4 X

S4YO

SPRITE 4 Y

9 S4Y7

A S5X7 S5XO

SPRITE 5 X

S5YO

SPRITE 5 Y

5Y7

C S6X7

S6XO SPRITE 6 X

S6YO

SPRITE 6 Y

D S6Y7

S7X7

S7XO SPRITE 7 X

Component

7Y7

RC7 RC6 RC5

S7YO SPRITE 7 Y

Component

7X8 S6X8 S5X8 S4X8

S3X8 S2X8 SIX8

SOX8 MSB of X

COORD.

RC8

ECM

BMM

BlNK RSEl

YSCl2 Y5Cll YSClO

Y SCROll

MODE

RC4 RC3 RC2 RCI RCO RASTER

13 PX7

14 PY7 lPXO LIGHT PEN X lPYO LIGHT PEN Y

159

Dee Hex DB7

DB6 DBS DB4 DB3 DB2 DBI DBO

IS SE7 SEO SPRITE

ENABLE

(ON/OFF)

16 N.C. N.C.

RST MCM CSEl XSCl2 XSClIXSClO

X SCROll

MODE

17 SEXY7

SEXYOSPRITE

EXPAND Y

18 VS13 VS12

VSlI VSIO CBI3 CBI2 CBII N.C.

SCREEN

Character

Memory

IRQ

N.C.

BSP7

IC SCM7

N.C.

lPIRQ

ISSC

ISBC

RIRQ

Interupt

Request's

N.C.

MlPI MISSC MISBC MRIRQ Interupt

Request

MASKS

BSPO

Background-

Sprite

PRIORITY

SCMO MUlTICOlOR

SPRITE

SelECT

ID SEXX7

IE SSC7

SBC7

SEXXO SPRITE

EXPAND

SSCO

Sprite-Sprite

COLLISION

SBCO

Sprite-

Background

COLLISION

160

26 6

27 7

28 8

29 9

2A 10

2B 11

2C 12

2E 14

20 0

21 1

23 3

24 4

25 5

COLOR CODES

0 BLACK

WHITE

RED

CYAN

PURPLE

GREEN

BLUE

YellOW

ORANGE

BROWN l T RED

GRAY 1

GRAY 2

LT GREEN

IT BLUE

GRAY 3

SMC 1

SOCOl

SICOl

S2COl

S3COl

S4COl

S5COl

S6COl

S7COl

DEC

HEX COLOR

EXT 1 EXTERIORCOl

BKGDO

BKGDI

BKGD2

BKGD3

SMC 0

SPRITE

MUlTiCOlOR 0

SPRITE0 COLOR

4 lEGEND:

ONLY COLORS 0-7 MAY BE USED IN MUlTICOlOR CHARACTERMODE

161

APPENDIX P

COMMODORE 64 SOUND CONTROL

SETTINGS

This handy

table gives you the key numbers you need to use in your

sound programs, according to which of the Commodore 64's 3 voices you want to use. To set or adjust a sound control in your BASIC program, just POKE the number from the second column, followed by a comma (,) and a number from the chart.

. . like this: POKE 54276,17

(Selects a Triangle Waveform for VOICE 1).

Remember that you must set the VOLUME before you can generate sound. POKE54296 followed by a number from 0 to 15 sets the volume for all 3 voices.

It takes 2 separate POKEs to generate each musical note

. . .

for example POKE54273,34:POKE54272,75 designates low C in the sample scale below.

Also.

. . you aren't limited to the numbers shown in the tables.

If 34 doesn't sound "right" for a low C, try 35. To provide a higher SUSTAIN or ATTACKrate than those shown, add two or more SUSTAIN numbers together.

(Examples: POKE54277,96 combines two attack rates (32 and

64) for a combined higher attack rate

. . but. . .

POKE54277,20 provides a low attack rate (16) and a medium decay rate (4).

162

SETTING VOLUME-SAME

FOR ALL3 VOICES

TO PLAY A NOTE C C#

(0 to 15

. . .

0 to 255 depending on range)

D#E

F# G G#

A# B C C#

HIGH FREQUENCY

54273 34 36 38 40 43 45

48 51 54

61 64 68 72

WAVEFORM POKE

54276

172 126 188 149 169

LOW FREQUENCY 54272 75 85 126 200 52

198 127 97 111

TRIANGLE

SAWTOOTH

PULSE NOISE

65 129

PULSE RATE(Pulse Waveform)

HI PULSE

LO PULSE

54275

54274

A value of 0 to 15 (for Pul.e waveform only)

A value of 0 to 255 (for

Pul.e waveform only)

ATTACK/DECAY

POKE ATK4

ATK3

ATK2

ATKI DEC4

DEC3

DEC2

DECI

54277

128 64 32 16

8 4

SUSTAIN/RELEASE

POKE

SUS4

SUS3

SUS2 SUSI REL4 REL3

54278 128 64 32 16 8

o

REL2

REL1

TO PLAY A NOTE C

C# D D# E F F# G

HIGH FREQUENCY

54280 34 36 38

40 43 45 48 51

LOW FREQUENCY

54279 75 85 126 200 52

198 127 97

111

WAVEFORM POKE

54283

TRIANGLE SAWTOOTH PULSE

33 65

A A#

NOISE

129

C C#

57 61 64 68 72

172 126 188 149 169

PULSE RATE

HI PULSE

LO PULSE

ATTACK/DECAY

SUSTAIN/RELEASE

54282

54281

POKE

5-428-4

POKE

54285

A value of 0 to 15 (for Pul.e waveform only)

A value of 0 to 255 (for

Pulse waveform only)

ATK4

ATK3 ATK2 ATKI DEC4

DEC3 DEC2 DECI

128

64 32 16

SUS4 SUS3

SUS2 SUSI

128

64 32

8 -4 2 1

REL4

REL3 REL2 REL1

8 4 2

163

" ocm

F FII.

GII.

I TOop.LAYA

NOoTE C

CII

HIGH FREQUENCY 54287 34

36 38 40 43

45 48 51 54

LOW FREQUENCY 54286 75 85 126 200 52 198 127 97 111

WAVEFORM POKE

54290

TRIANGLE SAWTOOTH

17 33

PUL5E

A All

, ..

57 61 64 68 72

172 126 188 149 169

NOISE

129

PULSE RATE

HI PULSE

LO PULSE

ATTACK/DECAY

54289

54288

POKE

54291

A value of 0 to 15 (for Pul.e waveform only)

A value of 0 to 255 (for Pul.e waveform only)

ATK4

128

ATK3

ATK2

ATKI

DEC4

DEC3

DEC2 DECI

8 4 2 I

SUSTAIN/RELEASE POKE

54292

SUS4

SUS3 SUS2 SUSI REl4

128 64

16 8

REl3

RE12 RELI

TRY THESE SETTINGS TO SIMULATE DIFFERENT INSTRUMENTS

Instrument Waveform

Sustain/Release Pulse Rate

Piano

Flute

Harpsichord

Xylophone

Organ

Colliape

Accordion

Trumpet

Pulse

Triange

Sawtooth

Triangle

Sawtooth

Attack/Decay

102

0 240

240

Hi-O, Lo-255

Not applicable

MEANINGS OF SOUND TERMS

ADSR-Attack!Oecay/SustainlRel8Gse

Attack-rat.

sound rises to peak volume

D.coy-rat.

50und falls from peak volume to Sustain level

Sustain-prolong note at certain volume

Releas.-rote at which volume foU. from Sustain level

Waveform-".hape"

Pulse-tone quality oflOund waye of Pulse Waveform

NOTE: Attack/Decay and Sustain/Release settings should always be POKEd in your program

BEFORE the Waveform is POKEd.

164

INDEX

Abbreviations, BASIC commands, 130,

131

Accessories, viii, 106-108

Addition, 23, 26-27, 113

AND operator, 114

Animation, 43-44, 65-66, 69-75, 132,

138-139

Arithmetic, Operators,

113-114

23, 26-27,

Arithmetic, Formulas, 23, 26-27, 113,

120, 140

Arrays, 95-103

ASC function, 128, 135-137

ASCII character codes, 135-137

BASIC abbreviations, 130-131 commands, 114-117 numeric functions, 125-127 operators, 113-114 other functions, 129 statements, 117-125 string functions, 128 variables, 112-113

Bibliography, 156-158

Binary arithmetic, 75-77

Bit, 75-76

Business aids, 108

Byte, 76

Calculations, 22-29

Cassette tape recorder (audio), viii, 3,

18-20,21

Cassette tape recorder (video), 7

Cassette, port 3

CHR$ function, 36-37, 46-47, 53,

58-60, 113, 128, 135-137, 148

CLR statement, 117

CLR/HOME key, 15

Clock, 113

CLOSE statement, 117

Color adjustment, 11-12

CHR$ codes, 58 keys, 56-57 memory map, 64, 139

PEEKS and POKES, 60-61 screen and border, 60-63, 138

Commands, BASIC, 114-117

Commodore key, (see graphics keys)

Connections optional, 6-7 rear, 2-3 side panel, 2

TV/Monitor, 3-5

CO NT command, 114

ConTRL key, 11, 16

COSine function, 126

CuRSoR keys, 10, 15

Correcting errors, 34

Cursor, 10

DATASSETTE recorder, (see cassette tape recorder)

Data, loading and saving (disk), 18-21

Data, loading and saving (tape),

18-21

DATAstatement, 92-94, 118

DEFine statement, 118

Delay loop, 61, 65

DELete key, 15

DIMension statement, 118-119

Division, 23, 26, 27, 113

Duration, (see For

. . .

Next)

Editing programs, 15, 34

END statement, 119

Equal, not-equal-to, signs, 23, 26-27,

114

Equations, 114

Error messages, 22-23, 150-151

Expansion port, 141-142

EXPonent function, 126

Exponentiation, 25-27, 113

Files, (DATASSETTE), 21, 110-111

Files, (disk), 21,110-111

FOR statement, 119

FRE function, 129

Functions, 125-129

Game controls and ports, 2-3, 141

GET statement, 47-48, 119-120

GET# statement, 120

Getti n9 sta rted, 13-29

GOSUB statement, 120

GOTO (GO TO) statement, 32-34, 120

165

Graphic keys, 17, 56-57, 61, 132-137

Graphic symbols, (see graphic keys)

Greater than, 114

Hyperbolic functions, 140

IEEE-488Interface, 2-3, 141

IF . . . THEN statement, 37-39, 120-

121

INPl/T statement, 45-47, 121

INPUT#, 121

INSert key, 15

INTeger function, 126

Integer variable, 112

I/O pinouts, 141-143

I/O ports, 2-7, 141-143

Joysticks, 2-3, 141

Keyboard, 14-17

LEFT$function, 128

LENgth function, 128

Less than, 114

LETstatement, 121

LIST command, 33-34, 115

LOAD command, 115

LOADing programs on tape, 18-20

LOGarithm function, 126

Loops, 39-40, 43-45

Lower case characters, 14-17

Mathematics formulas, 23-27 function table, 140 symbols, 24-27, 38, 114

Memory expansion, 2-4, 142

Memory maps, 62-65

MID$ function, 128

Modulator, RF, 4-7

Multiplication, 24, 113

Music, 79-90

Names program, 18-21 variable, 34-37

NEW command, 115

NEXT statement, 121-122

NOT operator, 114

Numeric variables, 36-37 o

ON statement, 122

OPEN statement, 122

Operators arithmetic, 113 logical, 114 relational, 114 p

Parentheses, 28

PEEK function, 60-62

Peripherals, viii, 2-8, 107-109

POKE statement, 60-61

Ports, I/O, 2-3, 141-143

POS function, 129

PRINT statement, 23-29, 123-124

PRINT#, 124

Programs editing, 15, 34 line numbering, 32-33 loading/saving (DATASSETTE),18-21 loading/saving (disk), 18-21

Prompt, 45

Quotation marks, 22

RaNDom function, 48-53, 126

Random numbers, 48-53

READ statement, 124

REMark statement, 124

Reserved words, (see Command statements)

Restore key, 15, 18

RESTOREstatement, 124

Return key, 15, 18

RETURN statement, 124

RIGHT$ function, 128

RUN command, 116

RUN/STOP key, 16-17

SAVEcommand, 21, 116

Saving programs (DATASSETTE),21

Saving programs (disk), 21

Screen memory maps, 62-63, 138

SGN, function, 127

Shift key, 14-15, 17

SINe function, 127

Sound effects, 89-90

SPC function, 129

166

SPRITE EDITOR, vii, 69-76

SPRITE graphics, vii, 69-76

SQuaRe function, 127

STOP command, 125

STOP key, 16-17

String variables, 36-37, 112-113

STR$ function, 128

Subscripted variables, 95-98, 112-113

Subtraction, 24, 113

Syntax error, 22

SYS statement, 125

TAB function, 129

TAN function, 127

TI variable, 113

TI$ variable, 113

Time clock, 113

TV connections, 3-7 u

Upper/Lower Case mode, 14

USR function, 127

User defined function, (see DEF)

VALue function, 128

Variables array, 95-103, 113 dimensions, 98-103, 113 floating point, 95-103, 113 integer, 95-103, 112 numeric, 95-103, 112 string ($), 95-103, 112

VERIFYcommand, 117

Voice, 80-90, 162-164

WAIT command, 125

Writing to tape, 110

Z-80, vii, 108

167

Commodore hopes you've enjoyed the COMMODORE

USER'S GUIDE.

Although this manual contains some programming information and tips, it is NOT intended to be a

Programmer's Reference Manual.

For those of you who are advanced programmers and computer hobbyists Commodore suggests that you consider purchasing the COMMO-

DORE 64 PROGRAMMER'S REFERENCE GUIDE

available through your local Commodore dealer.

In addition updates and corrections as well as programming hints and tips are available in the COMMODORE and POWER

PLAY magazines, on the COMMODORE database of the

COMPUSERVE INFORMATION NETWORK, accessed through a VICMODEM.

SIMPLE VARIABLES

Type

Nam~ Range

Real XY ::1.701411183E+38

~2.93873S88E-39

Integ~r

String

XY" ~32767

XY$ 0 to 255 charaCters

X is a tener (A-Z), Y is a Jener ar number (0.9). Variable names can be more than 2 choracters. but only the firsl two are recog.

niud.

ARRAY "'RIAlLES

Type

Singl~ Dimension

Two-Dimension

Three-Dimension

COMMODORE 64 QUICK REFERENCE CARD

Name

XY(S)

XY(5,S)

XY(S,5,S)

Arrays of up 10 eleven .Iements (subscripts 0.10) can be used where n.ed~d. Anay$ with more Ihan eleven er~m.nts need 10 be DIMens;on.d.

SPC(X)

POS(X)

ClR/HOME

SHIFT CLRlHOME

SHIFT INST/DEL

INST/DEL

CTRL

CRSR Keys

Commodore Key

PRINTs X blanks on line

Relurns currenl cursor position

Posilions cursor to left comer of scr~~n

CI.ars

"Home" scr.en

position and places cursor in

Inserts spac.

at current cursor position

Deletes character at currenl cursor position

When us.d

wilh numeric color key, sel.cts

text color.

May b~ used in

PRINT slatement.

Moves cursor up, down.

left, righl

When used with SHin s.lects

betw..n

upperllower case and graphic display mod..

When us.d wilh numeric color key, selects oplional lext color

AlGEBRAIC OPERATORS

= Assigns ...alu.

10 variabl.

-

"'egalion

Exponentiation

· Multiplication

Division

+ Addition

Sublraction

RELATIONAL AND LOGiCAl OPERATORS

Equal

<> NOl Equal 10

< Less Than

Greol~r Than

Less Thon or Equal To

Grealer Thon or Equal To

NOT logical "Nor"

AND logical "And"

OR logical "Or"

Expr.ssion..quals

1 if true, 0 if fals~.

SYSTEM COMMANDS

LOAD

"NAME"

SAlE "NAM£'"

LOAD "NAME" ,8

SAlE "NAME" ,8

. VERIFY "NAME"

RUN

RUN xxx

STOP

END

CONT

PEEK(X)

POKE X,Y

SYS xxxxx

WAIT X. Y.Z

USR(X) loads

Sav.s

a program a program from tope on lope loads a program from disk

Sa s a program 10 disk

Verifies Ihal program was SAlEd wilhoul ~rrors

Execules a program

Execules program storting

"""

Holts execution

Ends execution at line

Continues program lin.

where program

R.lums

location conlents

X execution from was halted of memory

Chang.s

contenls

10 ...alue

Y of 10cOlion X

Jumps program,

Program location to .xecule

X, when a machine starting at JCXXXX wafts until conlents

FORed with language of'

Z and

ANDed with Y, is nonzero.

Posses value of X 10 a machine language subrouline

EDITING AND FORMAJTlNG COMMANDS

LIST

UST A-.B

REMMessage tAB(X)

Lisn entire program

Usts from line A to line B

Comment message can be listed but is ignored

Used pasltions during on screen program

In PRINT stotements.

execution

Spaces X

ARRAYS AND STRINGS

DIM A(X. Y.Z)

LEN(XS)

STRS(X)

UX$)

CHRS(X)

ASC(X$)

LEFT$(AS.X)

RIGHTS(A$,X)

MIDS(AS,X, Y)

Sets maximum subscripts for A; reserves space for (X+1)-(Y+1)-CZ+1) eJem.nts starting 01 A(O,O,O)

Returns number of characters in X$

Re",rns numeric value of X.

con rt.d 10 a string

Returns num.ric value of AS, up 10 first nonnumeric character

Returns ASCII character whose code is X

Returns ASCII cod. for fir" character of XS

Retums leftmost X characlers of AS

Relurns rightmost X characters of AS

Relurns Y characters of AS

Slorting at character X

INPUT/OUTPUTCOMMANDS

INPUTAS OR A PRINTs'?' on screen and waits for

INPUT"ABC";A

GETA$ or A

DATAA,"B",C

READA$ or A

RESTORE

PRINT"A-";A us.r to enter a sIring or value

PRINTsmessage and waits for user to ent.r value. Can also INPUTAS

't'Ibits for user 10 type onecharacter value; no RETURNneed.d

Initializes a s.t of values thol can be used by

READ statement

Assigns nexl DATAvalue 10 AS or A

Res~Is dOlo pointer to start

READingthe DATAlist again

PRINTsSIring 'A= ' and value of A

./ suppresses spac.s -': tabs data to next field.

PROGRAM ROW

GOTO X Branche. 10 line X

If A=3 THEN 10 If assertion is Irue THENexecute following port of statement.

If fal...

execute next line number

FOR A= 1 TO 10 Executes all statements betw.en

FOR

STEP2 : NEXT

NEXTA

GOSUB 2000

RETURN and corresponding NEXT.with A going from 1 10 10 by 2. SI.p size is 1 unless s~jfied

Defines .nd of loop. A is optional

Branches 10 subroutine slarting at line 2000

Marks end of subroutine. R~turns to stat.ment

following mosl recent

GOSUB

ON X GOTO A,B Bronches 10 xth line number on list. If X-I branches 10 A, elc.

ON X GOSUB A,B Bronches 10 subroutine at Xth line number in list

(::

commodore

COMPUTER

Commodore Business Machines. Inc.-Computer Systems Division.

487 Devon Park Drive. Wayne. PA 19087

DISTRIBUTEDBY

Howatd W. Sams & CO., Inc.

4300 W.

62nd Street,

Indianapolis, Indiana

46268 USA

ISBN:

0.672.22010.5

$12.95/22010

হ্যালো! আমি একটি এআই চ্যাটবট যা বিশেষভাবে Commodore 64 Personal Computers User Guide এর সাথে আপনাকে সহায়তা করার জন্য প্রশিক্ষিত। আমি পুঙ্খানুপুঙ্খভাবে নথিটি পর্যালোচনা করেছি এবং আপনার প্রয়োজনীয় সঠিক তথ্য সনাক্ত করতে বা স্পষ্ট এবং সহজ শর্তে সামগ্রী ব্যাখ্যা করতে সহায়তা করতে পারি। আপনি নির্দিষ্ট বৈশিষ্ট্য, সমস্যা সমাধানের পদক্ষেপ বা সাধারণ ব্যবহার সম্পর্কে নির্দেশিকা খুঁজছেন কিনা, নির্দ্বিধায় আপনার প্রশ্ন জিজ্ঞাসা করুন। আপনার উদ্বেগ বা চাহিদা সম্পর্কে আপনি যত বেশি বিবরণ দেবেন, আমি তত বেশি নির্ভুলভাবে এবং কার্যকরভাবে আপনাকে সহায়তা করতে পারি!

সহকারী টাইপ করছে

সহকারী কীবোর্ডের বাইরে। অনুগ্রহ করে পরে আবার চেষ্টা করুন।

মনে হচ্ছে আপনি এমন একটি নথিতে পৌঁছেছেন যা একাধিক ভাষায় লেখা, যার মধ্যে একটি আপনার মাতৃভাষা নয়। আপনি আপনার পছন্দের ভাষা ছাড়া অন্য ভাষার পৃষ্ঠাগুলি সাময়িকভাবে লুকাতে নিম্নলিখিত লিঙ্কগুলি ব্যবহার করতে পারেন।

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