Radio Shack TRS-80 PC-3 Owner's Manual page 130

END
Abbreviations: E., EN.
Purpose
The EN D verb is used to signal the end of a program.
Use
When multiple programs are loaded into memory at the same time, a mark must be included to indicate where each program ends
so that execution does not continue from one program to another. This is done by including an END verb as the last statement in
the program.
Examples
10 PRINT "HELLO"
20 END
30 PRINT "GOODBYE"
40 END
With these programs in memory a 'RUN 10' prints 'HELLO', but not 'GOODBYE'. 'RUN 30' prints
'GOODBYE'.
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