CSE306

Processing Systems and Structures

Lockwood, Spring 2003

Introduction

A list of scores is given to you in the form of a database. For CSE306, our database is collection of records that each hold a student ID and individual raw scores. The ID is an alpha-numeric string stored as 5 ASCII characters and terminated with a '$' symbol. Each of the 16 individual raw scores is stored as a 1-byte unsigned integer. The total score is represented as a 2-byte unsigned integer. In total, each CSE306 record occupies 24 bytes.

Sample databases are included with this assignment. The real database with your IDs and scores is available on-line from the gradebook page.

Record Format

For this machine problem, you will use the INCLUDE directive to read a database of fictitious CSE306 scores into your program. This directive will insert the contents of the specified file into your .ASM program at the time you assemble with MASM. The gbk-test.dta and gbk-big.dta files each define a variable called gbk which holds an entire database of student records as well as a variable called numrec which stores the number of records in the database. The contents of gbk-test.dta is shown below:

; Format: id,'$',hw0,hw1,hw2,hw3,hw4,hw5,
;         mp0,mp1,mp2,mp3,mp4,mp5,mp6(project),
;         exam1,exam2,final

gbk db 'PRFCT','$',25,75,75,75,75,75, 25,50,50,50,50,50,125, 150,150,200, 0,0
    db 'DOPEY','$',10,40,40,40,40,40,  0,20,30,40,40,40, 70,  50, 60, 70, 0,0
    db 'HAPPY','$',25,20,75,25,75,25, 25,50,35,50,40,50,100, 115, 90,150, 0,0
    db 'LUCKY','$',20,70,70,70,70,70, 20,40,40,40,40,40, 90, 110,120,150, 0,0
    db 'ANGRY','$',20,40,40,40,40,30, 10,20,30,40,40,30, 70,  60, 50, 70, 0,0

numrec dw 5 

A similar table of current scores for this class can be dynamically generated and downloaded from the CSE306 on-line gradebot.

Procedures

• CompTotal
  • Purpose: Computes the total score (total) for each student in the gradebook as the sum of HW, MP, exam, and the final scores.
  • Input: numrec variable and hw, mp, exam, and final fields of gbk records.
  • Output: total field of gbk records.
  • Note1: Recall that the subtotal of the homework scores needs to be divided by four.
  • Note2: Observe that you are adding byte-sized integers to compute a word-sized total.
  • Hint1: There is an efficient opcode that divides an integer by a power of two.
  • Hint2: Avoid repetitive code by using loops to iterate though the records and compute sums.
  • Points: 16

• FillTable
  • Purpose: Compute the score distribution array, (ScoreDist), as the frequency of students that achieve a range of scores. This routine should also compute the lowest and highest score ranges.
  • Input: total fields of the gbk array
  • Outputs: ScoreDist array and MinBin, MaxBin variables.
  • Description: Each element (or "bin") of the ScoreDist array represents a 16-point range of total points. The array has been defined with 65 elements to represent all possible scores between 0 and 1030. The first bin, (ScoreDist[0]), represents the number of students that have scores between 0 and 15. The last bin (ScoreDist[64]), represents the number of students that have scores between 1024 and 1039. The variables MinBin and Maxbin represent the lowest and highest score range obtained by one or more students. MinBin represents the first non-empty bin and MaxBin represents the last non-empty bin.
  • Hint: The ScoreDist array can be computed using only a single pass through the gbk array.
  • Points: 17

• PlotChart
  • Purpose: Plots the distibution chart using the ASCII asterisk (*) symbol to represent the number of students obtaining the same score range.
  • Inputs: ScoreDist array and MinBin, MaxBin variables.
  • Output: Prints to the screen
  • Hint: Use the BINASC, DSPMSG, and DSPOUT routines of LIB306. Be sure to note how registers are used and modified by each routine.
  • Points: 17

Sample Output

• For the sample database (gbk-test.dta, as shown above), the computed scores totals are: PRFCT=1000 (3E8h), DOPEY=472 (1D8h), HAPPY=766 (2FEh), LUCKY=782 (30Eh), and ANGRY=472 (1D8h). The expected output of the program is shown below:

   464 ..    479 **
   480 ..    495 
   496 ..    511 
   512 ..    527 
   528 ..    543 
   544 ..    559 
   560 ..    575 
   576 ..    591 
   592 ..    607 
   608 ..    623 
   624 ..    639 
   640 ..    655 
   656 ..    671 
   672 ..    687 
   688 ..    703 
   704 ..    719 
   720 ..    735 
   736 ..    751 
   752 ..    767 *
   768 ..    783 *
   784 ..    799 
   800 ..    815 
   816 ..    831 
   832 ..    847 
   848 ..    863 
   864 ..    879 
   880 ..    895 
   896 ..    911 
   912 ..    927 
   928 ..    943 
   944 ..    959 
   960 ..    975 
   976 ..    991 
   992 ..   1007 *

LIBMP1 Calls: 
CompTotal 
FillTable 
PlotChart 

• Note that the inclusive range of values for the scores is printed on each line of the distribution table.
• Observe that the printing of scores begins and ends at the minimum and maximum range

• For the larger database (gbk-big.dta), the expected output would be:

   640 ..    655 *
   656 ..    671 *
   672 ..    687 
   688 ..    703 *
   704 ..    719 ***
   720 ..    735 *
   736 ..    751 ***
   752 ..    767 ***
   768 ..    783 *******
   784 ..    799 ********
   800 ..    815 ****
   816 ..    831 *********
   832 ..    847 *****
   848 ..    863 ************
   864 ..    879 ***********
   880 ..    895 ********
   896 ..    911 ***
   912 ..    927 *
   928 ..    943 *
   944 ..    959 ***

LIBMP1 Calls: 
CompTotal 
FillTable 
PlotChart 

• You can test this case with your program by modifying the INCLUDE statement in your variable section to: INCLUDE gbk-big.dta
• In general, Your output should match the output of the LIBMP1 routines for any input.

Preliminary Procedure

• Download the empty MP1 program (MP1.ASM)), example database files (gbk-test.dta and gbk-big.dta), sample output (gbk-test.out and gbk-big.out), libraries (libmp1.lib and lib306.lib), and Makefile by downloading mp1.zip.
• Run nmake to build an executable program using the given CSE306 and LIBMP1 library functions.
• As with MP0, use a text editor to modify the program. As given, the program uses LIBMP1 routines to implement all functionality. To receive full credit for the assignment, you will need to implement each of the subroutines described above with your own code.
• As with MP0, use CodeView (CV MP1) to debug and test your program. Because you only receive credit for procedures that function completely as specified, it is best to debug each routine individually.
• By modifying a few comments, you can mix and match usage of your own code and Library routines. You may notice that the LIBMP1 routines contain extraneous and difficult-to-read code. They are not meant to be easily unassembled!

Final Steps

1. Verify that your program meets all requirements for handin.
2. Demonstrate MP1.EXE to a TA or to the instructor.
   • You will be asked to recompile and demonstrate MP1 with different database files. Your program must work with all given input. Once approved, you are ready to turn in your program.
   • Be prepared to answer questions about any aspect of the operation of your program. The TAs will not accept an MP if you cannot fully explain the operation of your code.
   • Ask the TA to submit your GradeSheet.
3. Electrically upload your source code to the Gradebot Server.

MP1.ASM (Program framework)