Question

Develop an 8086-assembly program that prompts the user for a positive integer from 1 to 10 to calculate its factorial (n!) using a designated procedure (PROC) and a loop. If the input is outside of the valid range (1 to 10), the program shows an error message. The calculated factorial is then outputted via INT 21h/02h. The program is structured with a loop. The program must be well organized, well clear by adding comments. The calculated factorial values are stored in memory at address 6000H.

Submission Guidelines:
Submit the source code files (.asm).
Testing: Provide screenshots or other evidence of testing your programs with sample inputs.

Grading Criteria:
Correctness: The solutions should produce accurate results for the given problems.
Efficiency: Optimize the usage of loops, macros, and procedures for efficient execution.
Clarity and Readability: Ensure the code is well-structured, well-commented, and easy to read and understand.
Effective Address Usage: Demonstrate the effective use of addressing modes in the fourth problem.

Answer 1

To write an 8086-assembly program to calculate the factorial of a positive integer entered by the user, you need to prompt for a number, validate it, calculate the factorial using a loop, and output the result.

Step-by-step explanation:

To write an 8086-assembly program to calculate the factorial of a positive integer entered by the user, you can follow these steps:

1. Prompt the user to enter a number and store it in a register.
2. Check if the number is within the range of 1 to 10. If it is not, display an error message.
3. If the number is within the valid range, call a procedure that calculates the factorial using a loop.
4. In the procedure, initialize a variable with the value 1.
5. Use a loop to multiply the variable by the current number, decreasing the number by 1 in each iteration.
6. Store the result in memory at address 6000H.
7. Output the factorial value stored in memory using the INT 21h/02h function.