Atari 800 Basic Reference Manual

2 Gene ral Inf orm at ion
Logical Line: A logical line consists of one to three physical lines, and is ter-
minated either by a l;i#iii;lli or automatically when the maximum logical line
limit is reached. Each numbered line in a BASIC program consists of one logical
line when displayed on the screen. When entering a line which is longer than
one physical line, the cursor will automatically go to the beginning of the next
physical line when the end of the current physical line is reached . Ifi@ii!;lllis
not entered, then both physical lines will be part of the same logical line.
Operator: Operators are used in expressions. Operators include addition ( + ),
subtraction (- ), multiplication ( * ), division (/), exponentiatinn (A), greater than
(>), less than (<),equal to (= ) ,greater than or equal t o(>=), less than or equal to
( <,::: ), and not equal to ( < > ). The logical keywords AND, NOT and OR are also
operators. The + and - operators can also be used as unary operators; e. g., -3.
Do not put several unary operators in a row; e.g.,--3 , as the computer will in-
terpret it incorrectly.
Physical Line: One line of characters as displayed on a television screen.
String: A string is a group of characters enclosed in quotation marks.
"ABRACADABRA" is a string. So are " ATARI MAKES GREAT COMPUTERS"
and "123456789" . A string is much like a constant, as it too, may be stored in a
variable . A string v ariable is different, in that its name must end in the
character$. For example, the string "AT ARI 800" ma y be assigned to a variable
called A$ using (optional) LET like this:
10 LET A$="ATAF.J 8H0"
OR
(note quot ation marks)
(LET is optional; the
quotes are required.)
Quotation marks may n ot be used within a string. However , the closing quota-
tion can be omitted if it is the last character on a logical line. (See Section 7 -
STRINGS).
Variable: A variable is the name for a numerical or other quantity which may
(or may not) change. Variable name s ma y be up to 120 characters long.
However, a variable name must start with an alphabetic letter, and ma y contain
only capital letters and numerical digits. It is ad v isable not to use a ke yw o rd as a
variable name or as the first part of a va riable name as it m ay not be inte r preted
correctly. Examples of s toring a value in a vari a ble:
LETC 123Dt..J8= 1 . 234
LETI . .JARIABLE112=267 . 543
LETA=1
LET F5TH=6 . 5
LET TH J::;HO = 59 . :: : £19
Note: LET is optional and may be omitted)
Variable Name Limit: ATARI BASIC limits the user to 128 variable names . To
bypass this problem , use individual elements of an arra y instead of having
separate vari a ble names. BASIC keeps all refe r ence s to a variabl e which has
been deleted from a program , and the name still remains in the variable name
table.

Atari 800 Specifications

General

Brand	Atari
Model	800
Category	Desktop
Language	English