Atari 800 Basic Reference Manual

OPERATING
MODES
SPECIAL
FUNCTION
KEYS
sexp
exp
lineno
a data
filespec
String Expression: Can consist of a string variable, string literal
(constant), or a function that returns a string value.
Any expression, whether sexp or aexp.
Line Number: A constant that identifies a particular program
line in a deferred mode BASIC program. Must be any integer
from 0 through 32767. Line numbering determines the order of
program execution.
ATASCII Data: Any AT ASCII character excluding commas and
carriage returns. (See Appendix C.)
File Specification: A string expression that refers to a device
such as the keyboard or to a disk file. It contains information on
the type of I/0 device, its number, a colon, an optional file name,
and an optional filename extender. (See OPEN, Section 5. )
Example filespec: "D1:NATALIE.ED"
Direct Mode: Uses no line numbers and executes instruction immediately after
i;IJiiJ;I:I key is pressed.
Deferred Mode: Uses line numbers and delays execution ofinstruction(s) until
the RUN command is entered .
Execute Mode: Sometimes called Run mode . After RUN command is entered ,
each program line is processed and executed.
Memo Pad Mode: A non-programmable mode that allows the user to experi-
ment with the keyboard or to leave messages on the screen. Nothing written
while in Memo Pad mode affects the RAM-resident program.
II
Reverse (Inverse) Video key, or "ATARI LOGO KEY". Press-
ing this key causes the text to be reversed on the screen (dark
text on light background). Press key a second time to return to
normal text.
MOJ.Iitillo!ZJ;I Lower Case key: Pressing this key shif ts the screen characters
from upper case (capitals) to lower case. To restore the char a cters
to upper case, press the Ki@M key and the MOfW!l!l£.'1;1 key
simultaneously.
Escape key: Pressing this key causes a command to be entered
into a program for later execution.
Example: To clear the screen, you would enter:
10 PRINT " IB Bi3 MijUi;l "
and press 1&13 .
Escape is also used in conjunction with other keys to print special
graphic control characters. See Appendix F and back cover for
the specific keys and their screen-character representations.
General Information 5

Atari 800 Specifications

General

Brand	Atari
Model	800
Category	Desktop
Language	English