Business Programming I Fall – 2000 By Jim Payne Lecture 03Jim Payne - University of Tulsa2 A New...
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Transcript of Business Programming I Fall – 2000 By Jim Payne Lecture 03Jim Payne - University of Tulsa2 A New...
Business Programming I
Fall – 2000By
Jim Payne
Lecture 03 Jim Payne - University of Tulsa 2
A New Programming Language
In our previous sessions, we have learned to develop assembler language program solutions for simple arithmetic problems.
Today, we will begin the process of developing a brand new programming language.
Lecture 03 Jim Payne - University of Tulsa 3
A New Programming Language
Goals for our new high-level language:
1) Combine several assembler instructions into one high-level instruction.
2) Allow for numeric and alphanumeric variables.
3) Begin to trust the internal operations of the computer.
4) Improve Input and Output flexibility.
Lecture 03 Jim Payne - University of Tulsa 4
Replace Line Labels with Line #’s
In Billy-O, we used line labels like TOP or MID so we could jump to a new label. (e.g BRU TOP)
Let’s replace those labels with line numbers on each statement and the branching instructions with GOTO instructions. (e.g. 200 GOTO 100)
Lecture 03 Jim Payne - University of Tulsa 5
Input/Output Statements
Let’s replace the INP statements of Billy-O with an ACCEPT statement and the OUT statements with DISPLAY statements.
General Form:
ACCEPT variable,variable,…DISPLAY variable,variable,…
Lecture 03 Jim Payne - University of Tulsa 6
COMPUTE statement
Let’s create a very powerful new statement called the COMPUTE statement. It can replace several assembler statements with one.
COMPUTE D = A + B * C
REPLACES: LDA B, MPY C, ADD A, STA D
Lecture 03 Jim Payne - University of Tulsa 7
Conditional Branching
Let’s make our If logic more user friendly. When we wanted to count those exam scores >= 60, we did things like ADC –60, BNA TOP, etc.
Let’s replace that with an IF or Decision structure.
IF SCR >= 60COMPUTE COP = COP + 1
ELSECOMPUTE COF = COF + 1
ENDIF
Lecture 03 Jim Payne - University of Tulsa 8
Variable Types
Up to now, we have used only numeric type variables. In the future, we will need variables for handling text inputs. For now, let’s just agree to put a $ after any variable name that might contain non-numeric information.
i.e. ACCEPT NAME$, AGE
DATA John Brown, 23
Lecture 03 Jim Payne - University of Tulsa 9
New Instruction Set
ACCEPT DISPLAY GOTO
COMPUTE IF-ELSE-ENDIF
DATA
Bertha Method
IN Baske
t
70
80
100
40
10
999
Sum of Scores
Counter of Scores
Counter of Passing
0 00
STEPS: (In Pseudocode Form)Pick up a card from the in basket.
If score = 999, do what? Else do what?
NOT EQUAL 999: Add score to Sum of Scores, Add 1 to Counter of Scores. If score >= 60, Add 1 to Counter of Passing. Then go read next score.
EQUAL 999: Compute Average Score = Sum of Scores / Counter of Scores. Print out report answers. Quit Processing
Variable Naming
SCR = Individual Score
SOS = Sum of Scores
COS = Counter of Scores
COP = Counter of Passing
AVG = Average Score = SOS / COS
Pseudocode
Input a value for SCR
If SCR = 999
Compute AVG = SOS / COS
Print Results and Quit
Else
Compute SOS = SOS + SCR
Compute COS = COS + 1
If SCR >= 60
Compute COP = COP + 1
EndIf
Endif
Go to Top of Program
Flowchart of Logic
Start
Stop
Billy-O ProgramTOP INP SCR
LDA SCR
ADC -999
BZA MID
LDA SOS
ADD SCR
STA SOS
LDA COS
ADC 1
STA COS
LDA SCR
ADC -60
BNA TOP
LDA COP
ADC 1
STA COP
BRU TOP
MID LDA SOS
DIV COS
STA AVG
OUT AVG
OUT COS
OUT COP
HLT
SOS NUM 0
COS NUM 0
COP NUM 0
END
IN Baske
t
70
80
100
40
10
999
New Program
100 ACCEPT SCR
110 IF SCR = 999
120 GOTO 220
130 ELSE
140 COMPUTE SOS = SOS + SCR
150 COMPUTE COS = COS + 1
160 IF SCR >= 60
170 COMPUTE COP = COP + 1
180 ELSE
190 ENDIF
200 GOTO 100
210 ENDIF
220 COMPUTE AVG = SOS / COS
230 DISPLAY AVG, COS, COP
240 END
Flowchart
IN Baske
t
70
80
100
40
10
999
New Program
100 ACCEPT SCR
110 IF SCR = 999
120 GOTO 220
130 ELSE
140 COMPUTE SOS = SOS + SCR
150 COMPUTE COS = COS + 1
160 IF SCR >= 60
170 COMPUTE COP = COP + 1
180 ELSE
190 ENDIF
200 GOTO 100
210 END-IF
220 COMPUTE AVG = SOS / COS
230 DISPLAY AVG, COS, COP
240 END
Start
Stop
Original Pseudocode
Input a value for SCR
If SCR = 999
Compute AVG = SOS / COS
Print Results and Quit
Else
Compute SOS = SOS + SCR
Compute COS = COS + 1
If SCR >= 60
Compute COP = COP + 1
EndIf
Endif
Go to Top of Program
New Program Code100 ACCEPT SCR
110 IF SCR = 999
120 GOTO 220
130 ELSE
140 COMPUTE SOS = SOS + SCR
150 COMPUTE COS = COS + 1
160 IF SCR >= 60
170 COMPUTE COP = COP + 1
180 ELSE
190 ENDIF
200 GOTO 100
210 END-IF
220 COMPUTE AVG = SOS / COS
230 DISPLAY AVG, COS, COP
240 END
High-Level Language to Machine Code
High-Level Language
Assembler Language
Machine Language
Compilers – Interpreters -Translators
LDA A MPY B STA C
11011010010010001010101001
COMPUTE C = A * B
Lecture 03 Jim Payne - University of Tulsa 17
