Radio Shack TRS-80 Model 100 Basic Manual page 12

10 PRINT "JOHN SMITH"
RUN
JOI·-lN SM I TH
A more economical way of instructing the Computer to execute your program is to
press the RUN Function Key,
~.
This accomplishes the same thing as typing RUN
(ENTER).
Now try a slightly more ambitious program. Enter the following two-line program:
10 PRINT "RADIO SHACK MODEL 100"
20 GDTO 10
The second statement in this program begins with line number 20, indicating that this
instruction should be executed after the first line which has a smaller line number.
There is nothing special about the line numbers used in this program. The important
thing is that the PRINT instruction has a smaller line number than the GOTO
instruction.
Execute the program with the RUN command or by pressing
~.
As you can see, unlike the first single line program, this second program prints the
name within quotation marks repeatedly. This is known as an "infinite loop"
program because the GOTO statement in the second line of the program simply
transfers control back to the first line which prints the "string" (a group of characters
and/or numbers) again on the next line.
Because of this continuous transfer, the program has no way of terminating and so it
must be terminated manually by you. To "break" the program, press (BREAK)
«(SHIFT)
~).
When you press
~,
the Computer will display a message to show where the
program stopped when it was "broken. " For example:
in
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