c64-programmers_reference_guide-02-basic_language_vocabulary.pdf

INTRODUCTION

This chapter

explains CBM BASIC Language

keywords.

First we

give

you an easy to read

list of keywords,

their abbreviations

and what

each

letter

looks

like on

the

screen.

Then

explain

how

the

syntax

and

operation

of each

keyword

works in detail,

and

examples

are

shown

give you an

idea

to how to

use them

in your

programs.

As a

convenience,

Commodore

BASIC allows

you to

abbreviate

most

keywords.

Abbreviations

are

entered

by typing

enough

letters

the keyword

to distinguish

it from

all other

keywords,

with the last letter

the IIIiI key.

graphics

entered

holding

down

Abbreviations

NOT save

any

memory

when

they're

used

in pro-

grams,

because

all keywords

are

reduced

to single-character

"tokens"

by the

BASIC Interpreter.

When

program

containing

abbreviations

listed,

all keywords

appear

in their

fully spelled

form.

You can

use ab-

breviations

put

statements

onto

program

line even

if they

won't

fit

onto

the

aO-character

logical

screen

line.

The

Screen

Editor

works on an

aO-character

line. This means

that

if you use abbreviations

on any

line that

goes

over

ao characters,

you will NOT be

able

to edit

that

line when

LISTed. Instead,

what

you'll have

to do

is (1) retype

the

entire

line including all abbreviations,

or (2) break

the single line of code

into two

lines,

each

with

its own

line number,

etc.

A complete

list of keywords,

abbreviations,

and

their

appearance

the

screen

is presented

in Table

2-1.

They are

followed

by an

alpha-

betical

description

all

the

statements,

commands,

and

functions

available

on your

Commodore

64.

This chapter

also

explains

the

BASIC functions

built

into the

BASIC

Language

Interpreter.

Built-in functions

can

used

in direct

mode

statements

in any

program,

without

having

define

the

function

further.

This is NOT the case

with user-defined

functions.

The results

built-in BASIC functions

can

be used

as immediate

output

or they can be

assigned

variable

name

appropriate

type.

There

are

two

types

of BASIC functions:

1) NUMERIC

STRING

Arguments

built-in

functions

are

always

enclosed

in parentheses

().

The

parentheses

always

come

directly

after

the

function

keyword

and

NO SPACES between

the

last

letter

of the

keyword

and

the

left

parenthesis

BASIC LANGUAGE VOCABULARY

The type of argument

needed

is generally

decided

by the data

type in

the

result.

Functions which

return

a string

value

as their

result are

iden-

tified

by having

a dollar

sign ($) as the last character

of the keyword.

some

cases

string

functions

contain

one

or more

numeric

argument.

Numeric

functions

will

convert

between

integer

and

floating-point

format

needed.

In the

descriptions

that

follow,

the

data

type

of the

value

returned

is shown

with

each

function

name.

The types

of argu-

ments

are

also

given

with the

statement

format.

Table 2-1. COMMODORE64 BASICKEYWORDS

COMMAND

ABBREVIATION

SCREEN

FUNCTION TYPE

NUMERIC

ABS

A IDIIiI B

AND

A BIIiI N

AIZJ

NUMERIC

ASC

A EIIIiI S

NUMERIC

ATN

ABIIiI T

CHR$

. STRING

C []

C IDIIiI H

CL 0

CL EIIIiI 0

C 0

CLR

C BIIiI L

CMD

C lSI

CEIIIiIM

C 0

CONT

c.BII 0

COS

none

NUMERIC

COS

DATA

D IDIIiI A

D I!I

D EJ

DEF

DIM

D f;J

BASIC LANGUAGE VOCABULARY

COMMAND

SCREEN

ABBREVIATION

FUNCTION TYPE

END

E IDID

EXP

E Emil

NUMERIC

none

F BIIiI 0

'FOR

FRE

NUMERIC

F ,BIIiI

GET

G,EDIIII

GET#

none

GET#

GOSUB

BIIiI

GOTO

G ,BIIiI

none

INPUT

INPUT#

I 'BIIiI

none

INT

NUMERIC

INT

STRING

lEFT$

LE IDID

NUMERIC

none

LEN

LET

L EIDIiI

LIST

L EIDIiI

LOAD

L BID

LOG

'none

LOG

NUMERIC

'32

BASIC LANGUAGE VOCABULARY

COMMAND

SCREEN

ABBREVIATION

FUNCTION TYPE

M IIID

MID$

STRING

M EJ

NEW

none

NEW

N IIID E

N EI

N 0

N BIID 0

NOT

none

o BIID P

OPEN

none

PEEK

NUMERIC

P IIID E

pEJ

POKE

P 0

P BIID 0

POS

none

POS

NUMERIC

PRINT#

P IIID R

READ

R IIID E

REM

none

REM

RESTORE

REIIID S

RETURN

RE [[]

REBIID T

S RING

RIGHT$

R BIID

R 0

NUMERIC

RND

R BIID N

RUN

R CLI

REmlU

BASICLANGUAGE VOCABULARY

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: