Intel x86 Assembly

1. ( 9 points) Write an assembly program to calculate the factorial of an unsigned integer n ( n! )

- You need to prompt the user to enter an unsigned integer : Enter unsigned integer ( n! ) :

To do this , u se WriteString and ReadDec (see assignment6 , question3 for a similar example)

- Pass the entered number to the Factorial subroutine

- The calculated n! needs to be display ed on console screen from main subroutine - See the book page 305 - 306 where you will find main and factorial subroutine s .

- Make the required changes and run the program

- Use Step Into instead of S tep O ver to keep track of the stack, ESP, EBP, EIP during debugging

- To access the stack memory, copy the value of ESP from the register window and past it in the search text box in the memory window. Remember to have 0x ( it tells debugger that the number is a hexadecimal number) in front of the pasted ESP value ( 0x 4000407C ) . Submit the following: Lastname1.asm

A. What will happen to the Factorial programs output when you try to calculate 13! and why?

B. How many bytes of stack space will be used by the Factorial subroutine when calculating 3!?