Atari 800 User Manual

Introduction to Atari BASIC 39
No two line numbers can be the same. If the same line number is
used more than once in a program, the line most recently
entered will replace the original. Line numbers can range from 0
to 32767.
The execution sequence of a BASIC program is determined by
the value of its line number. The lowest line numbers will be
executed first, followed by program lines with higher line
numbers. Even if program lines are not arranged in sequential
order, the Atari interpreter will place the lines in the correct
order.
Adding program lines to a program stored in the Atari's RAM is
very easy. Just type in the line number followed by the program
line. The line will be inserted in the program in the position
indicated by its line number. For example, by adding the
following line,
35 PRINT "216-777-5579"
to the program in Illustration 3-1 , the phone number for Jim
Smith
will be displayed on the line following his city, state, and
zip.
Program lines can be deleted by typing the line number to be
deleted followed by Return. For example, the following entry,
30 ,
would result in line 30 being deleted.
Program lines can be changed by merely retyping the new line.
The existing line in the Atari's memory will be replaced with the
new line . For example, the following entry ,
10 PRINT "Thomas Hill"
would result in "Thomas Hill" being output rather than "Jim
Smith" in the program in Illustration 3-1 .
Program lines also can be changed by displaying them on the

Atari 800 Specifications

General

Processor	MOS Technology 6502
Processor Speed	1.79 MHz
ROM	10 KB
Graphics	ANTIC and GTIA chips
Release Year	1979
Display Resolution	up to 320 x 192
Colors	128 colors
Sound	4 channels
Storage	Cartridge, cassette, floppy disk
Ports	Cartridge, serial, monitor
Operating System	Atari OS