Radio Shack TRS-80 Model 100 Basic Manual page 17

When it is executed, it produces, as expected, the following:
NOW BROWN COW
A BASIC program can be edited a line at a time simply by retyping the entire line as
you have been doing.
To delete an entire line from a program, all you have to do is to type the line number
of the statement you wish to delete and press
~.
For example, list the current program:
P RI NT "HOW
"?
"NOW ";
PRINT "BROWN "; "COW"
Now type
20~
If you list the program again, you will see that line 20 has been effectively deleted:
1~ PRINT "HOW"; "NOW";
Ok
I
Retype line 20 to restore your program to its previous form:
10 PRINT "HOW "; "NOW";
20 PR I NT "BROWN
" j
"COW"
11