This assignment is practice in reading a dump.

Type your answers to these questions and submit them on Blackboard by the due date.

Be sure to include your name.

Show your work!

Run the following program. You can use the JCL we used in the lab training exercise.

DEBUG1   CSECT
         USING DEBUG1,15    Establish a base register 
         L     3,FIRST      Load a number into register 2
         L     4,SECOND     Load another number into register 4 
         SR    3,4          Add the two numbers 
         LA    5,THIRD      Register 5 will = address of THIRD
         L     6,CONST      Put CONST's value in register 6
         ST    3,0(5,6)     Store the result
         XDUMP FOURTH,4     Dump the result
         SR    6,6          Set register 6 to 0
         BCR   B'1111',14   Return to caller 
* This is a comment line.
NOTE     DC    CL19'STORAGE STARTS HERE'      
CONST    DC    F'2'         A constant = 2
FIRST    DC    F'193'       A number
SECOND   DC    F'89'        Another number 
THIRD    DS    XL4'00'      Yet another number 
FOURTH   DS    F            Difference of FIRST and SECOND
         END   DEBUG1       Program ends here

Use the resulting output to answer the following questions:

1. (1 point) Did this error occur (a) while the program was being assembled or (b) when it was being run?

2. (2 points) What is the address of the next instruction which will be executed?

3. (2 points) What is the value of the condition code at the time of the ABEND?

4. (2 points) What is the length of the instruction that caused the ABEND (a number of bytes)?

5. (2 points) What is the address of the instruction that caused the abend?

6. (2 points) What type of error occurred (number and name)?

7. (2 points) What actually causes this error?

8. (3 points) Correct the error by rewriting the section of code that caused it. (The difference should be stored in FOURTH.) (There are several correct ways to do this.)

9. (2 points) At the time of the ABEND, what is the value of register 3 in decimal?

10. (2 points) What does the value in register 3 represent at the time of the ABEND?

11. (3 points) Why is the address (LOC column) of the storage area with the label CONST on it at X'000034' when the DC statement whose address is X'000020' only takes up 19 bytes?

12. (2 points) What are the contents of the byte of user storage starting at address X'000033'? What do they represent?

13. (1 point) Why do we not have XDUMP output?

14. (2 points) How many bytes are taken up by the XDUMP pseudo-instruction?

15. (2 points) If we correct the error, what should be the value of the condition code at the end of the program (when we reach the BCR line)?