ECE291

Computer Engineering II

Lockwood, Spring 1997

Introduction

This program automatically generates a sequence of ten quiz questions. Each question is in the form of:

Question: Num1 Operation Num2 = Result

Problem Description

For each question, the program randomly selects a mathematical or logical operation. At the level 0, only one of the four basic arithmetic operations can appear { + - * / }. At all other levels, the program can also include the operations { % & | ^ } for the modulus operation (remainder), logical AND, logical OR, and logical XOR.

Sample Output

• Before you begin, be sure that you fully understand the assignment. Perhaps the best way to understand how the program works is to watch it operate. Visit the lab or download the code and run the library-based MP2.EXE. Try the game at different levels. Hit 'ESC' at any time to quit.

• Actual Output from Library-based MP2.EXE (MP2.OUT)

  --- Little (Visiting Assistant) Professor --- Select Difficulty Level 0:Simple 1:Basic 2:Moderate 3:Rough 4:ECE291ish ESC:Quit 1 Question 1: 3 * 3 = 9 Correct ! Question 2: 4 - 6 = -2 Correct ! Question 3: 5 % 7 = 5 Correct ! Question 4: 8 / 6 = 1 Correct ! Question 5: 1 | 5 = 5 Correct ! Question 6: 8 & 6 = 0 Correct ! Question 7: 9 + 5 = 14 Correct ! Question 8: 8 ^ 6 = 14 Correct ! Question 9: 1 * 1 = 2 Incorrect. The answer is: 1 Question 10: 8 - 7 = 4 Incorrect. The answer is: 1 8 Points. Select Difficulty Level 0:Simple 1:Basic 2:Moderate 3:Rough 4:ECE291ish ESC:Quit LIBMP2 Calls: -Random -PickNum -PickOp -CalcResult -ShowOp -ReadNum -CmpResult -MainLib DOSXIT: Exit to DOS

Implementation

Once you have coded your own MAIN routine, you may write the other routines in any order that you wish. For all procedures, input and output values are passed to and from the procedures via registers. If a register is not specified as an output, its value should not be altered by the routine. Use the stack to push and pop registers.

• Main
  
  • Using the routines described below, Implement the following pseudocode in assembly:

    Print Welcome Message Repeat { Set Score=0 Print Level Message Set Level=ReadNum For each question { PickNum ; Randomly generate first number PickOp ; Randomly select operation in {+,-,*,/,%,&,|,^} PIckNum ; Ramdomly generate second number (Repeat if Zero) ShowOp ; Prompt the user with the question CalcResult ; Compute Correct Answer as DX = AX (op=BL) DX ReadNum ; Read the user's Answer CmpResult ; Compare Results and increment score if correct } Print Score } Until End of Game

    Your code should replace the call to 'MainLib' in MP2.ASM.
    Your program output should should match MP2.OUT.

• Random
  
  • Inputs: None
  • Outputs: AX=Random number between 0 .. 2^16-1
  • Uses and modifieds variable: RandSeed
  • Summary:

    This routine generates and returns a pseudo-random number by multiplication and addition of large prime constants to a random number. The function is defined below:

    R(1)=RandSeed
    R(i+1) = RandSeed = ( K1 * R(i) + K2 ) % MaxValue

    Where
    • R(i) is the random value generated in the i-th call to the subroutine.
    • RandSeed is a variable that holds the initial random value and is updated with the result after each call to Random.
    • K1 and K2 are two large, prime-valued constants, defined as 55821 and 1 respectively.
    • MaxValue = 2^16-1 (0FFFFh)
    Hints & Observations
    • The first call to Random returns the original random number seed
    • Perform multiplication and division using the 16-bit unsigned operations.

• PickNum
  
  • Inputs: None
  • Outputs: AX=Random number between 0 .. Range
  • Uses Variable: Level
  • Calls Routine: Random
  • Summary:

    This routine returns a random number with a probability density function evenly distributed over 0 .. Range. Range is determined as a function of Level. Range is smaller for easy levels and larger for more difficult levels. Specifically, Range should be determined as follows:

    Level	Name	Range
    0	Simple	0.. 9
    1	Basic	0.. 9
    2	Moderate	0.. 15
    3	Rough	0.. 99
    4	ECE291ish	0.. 181

    Hints

    • Use the modulus operation and the Random routine.

• PickOp
  
  • Inputs: None
  • Outputs: BL=ASCII code for Randomly-chosen operation
  • Uses Variable: Level
  • Calls Routine: Random
  • Summary:

    This routine returns the ASCII value of a randomly-chosen operation. When Level=0, the return value should be a random element in the set of { + - * / }. For more difficult levels, the set of possible operations should also include { % & | ^ }.

• CalcResult
  
  • Inputs
    • AX=Num1
    • BL=ASCII-coded operation
    • DX=Num2
  • Outputs: DX = Result of Num1 (operation) Num2
  • Summary:

    This procedure performs the operation specified by BL on the numbers Num1 and Num2.
    The possible values of BL and their corresponding operations are summarized below:

    Cmd	Description	Example
    +	Addition	Num1 + Num2
    -	Subtraction	Num1 - Num2
    *	Multiplication	Num1 * Num2
    /	Division	Num1 / Num2
    %	Modulus (remainder)	Num1 % Num2
    &	Logical AND	Num1 & Num2
    |	Logical OR	Num1 | Num2
    ^	Exclusive OR (XOR)	Num1 ^ Num2

• ShowOp
  
  • Inputs
    • AX=Num1
    • BL=ASCII-coded operation
    • CX=Qnum
    • DX=Num2
  • Outputs: None
  • Summary:

    This routine prints a message in the format of:

    Question Qnum: Num1 operation Num2 =

    Refer to the sample output for examples.

• ReadNum
  
  • Inputs: None (Reads keyboard)
  • Outputs: AX=Number
  • Calls Routines: Kbdin, Dspout
  • Summary:

    This routine reads a number from the keyboard. Your routine must be as robust as the library routine given in LIBMP2. Specifically, ReadNum must:

    • Process the backspace key (ASCII 8) to delete a character
    • Allow for the input of negative ('-') numbers
    • Reject invalid user input.
    • Call MP2XIT if ESC is pressed

• CMPResult
  
  • Inputs:
    • AX=User's Answer
    • DX=Computer's Answer
  • Outputs: None
  • Uses and modifieds variable: Score
  • Summary:

    If the user's answer equals the computer's answer, the routine increments score and prints:
    Correct !
    Otherwise, the computer displays:
    Incorrect. The answer is: Result
    where Result is the computer's answer.
    See the sample output or run the game for examples.

Program Assignment

• Main: 10 pts
• Random: 5 pts
• PickNum: 5 pts
• PickOp: 5 pts
• ShowOp: 5 pts
• ReadNum: 7 pts
• CalcResult: 8 pts
• CMPResult: 5 pts

Preliminary Procedure

• Copy the empty MP2.ASM framework, Makefile, sample output, library files (LIBMP2.LIB and LIB291.LIB), and library-based MP2.EXE from the network drive to your home directory with the following command:
  xcopy /s E:\ece291\mp2 F:\mp2
• Alternatively, if you are working from home, click below to download
  mp2.zip
• You can Assemble and link your program with the nmake command.

Final Steps

1. Demonstrate MP2.EXE to a TA or to the instructor. You will be asked to reassemble and demonstrate MP2 for all levels for multiple runs.
2. Because the Random Routine uses a fixed seed, your program should choose the exact same operations as the library version.
3. Have the TA execute the handin program from your machine.
4. Print MP2.ASM and give it to to the same TA which approved your demonstration. Be sure that your name appears in your program.

MP2.ASM