Atari XL User Manual

34
The Ateri XL Handbook
JUMPS
The computer can be instructed to jump from one
program line to another using the command
GOTO. Enter this program:
10 GOTO 30
20 PRINT "LINE 20"
30 PRINT "LINE 30"
When it is RUN the message (LINE 20' is not seen
because the GOTO instruction in line 10 sends the
XL straight to line 30.
The jump can be to a lower numbered line. The
following program will go on for ever, unless you
stop it by pressing the BREAK key:
10 PRINT "ON AND ";
20 GOTO 10
This is called an endless loop, and is to be avoided!
DECISIONS
The commands IF and THEN are used in programs
to make decisions. A variable is tested, and one of
two alternative actions is taken, depending on the
result of the test.
10 FOR X = 1 TO 10
20 PRINT X
30 IF X = 5 THEN PRINT "X = 5"
40 FOR P = 0 TO 200 : NEXT P
50 NEXT X
The format of IF ... T-HEN is:
IF (condition) THE N (instructions)

Atari XL Specifications

General

Brand	Atari
Model	XL
Category	Desktop
Language	English