Radio Shack TRS-80 PC-4 Owner's Manual page 44

(2) Conversation type debug
If an error occurs during program execution, an error message will be shown on the
display. These errors will be shown in line units and will indicate the kind of BASIC
language error. Based on the error message which is shown on the display, debugging
is then manually performed while conversing with the display. For the meaning of the
error messages, refer to the Error Message List on page 64.
Example:
10 INPUT X
20 Y=Xt2+3*X+ 15
30PRINTY
40 END
Suppose line 20 of the above program is mistakenly
input as follows.
20 Y=Xt2+3X+15
Operation:
• If this program is executed, a
I I
1" will
be
displayed
as a result of the INPUT statement on line 10.
I!@~RUN
III
• Suppose "45" is input at this time. The display would show.
45 lID
I
ERR2 P0-20
• This means that
~'a
syntax error occurred on line 20". Confirm the program contents.
20 Y=Xt2+3X+
I
P - 123456789
El~][TI
LIST 20111
• The"
*"
was omitted between "3" and "X" on line 20. Therefore, correct it by
following the procedure for program editing.
OBI
PR INT Y
-41-