Business Programming I

1
Business Programming I

• Fall 2000
• By
• Jim Payne

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.

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.

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)
• Lets replace those labels with line numbers
  on each statement and the branching instructions
  with GOTO instructions. (e.g. 200 GOTO 100)

5
Input/Output Statements

• Lets 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,

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COMPUTE statement

• Lets 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

7
Conditional Branching

• Lets make our If logic more user friendly.
  When we wanted to count those exam scores gt 60,
  we did things like ADC 60, BNA TOP, etc.
• Lets replace that with an IF or Decision
  structure.
• IF SCR gt 60
• COMPUTE COP COP 1
• ELSE
• COMPUTE COF COF 1
• ENDIF

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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, lets just
agree to put a after any variable name that
might contain non-numeric information. i.e.
ACCEPT NAME, AGE DATA John Brown, 23
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New Instruction Set
10
Bertha Method
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 gt
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
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Variable Naming
SCR Individual Score SOS Sum of Scores COS
Counter of Scores COP Counter of Passing AVG
Average Score SOS / COS
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Pseudocode
Flowchart of Logic
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 gt 60
Compute COP COP 1 EndIf Endif Go to
Top of Program
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Billy-O Program
New Program
TOP 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 T
OP MID LDA SOS DIV COS STA AVG OUT AVG OUT COS
OUT COP HLT
SOS NUM 0 COS NUM 0 COP NUM 0 END

• ACCEPT SCR
• 110 IF SCR 999
• 120 GOTO 220
• 130 ELSE
• 140 COMPUTE SOS SOS SCR
• COMPUTE COS COS 1
• 160 IF SCR gt 60
• COMPUTE COP COP 1
• 180 ELSE
• 190 ENDIF
• GOTO 100
• 210 ENDIF
• COMPUTE AVG SOS / COS
• 230 DISPLAY AVG, COS, COP
• 240 END

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Flowchart
New Program

• ACCEPT SCR
• 110 IF SCR 999
• 120 GOTO 220
• 130 ELSE
• 140 COMPUTE SOS SOS SCR
• COMPUTE COS COS 1
• 160 IF SCR gt 60
• COMPUTE COP COP 1
• 180 ELSE
• 190 ENDIF
• GOTO 100
• 210 END-IF
• COMPUTE AVG SOS / COS
• 230 DISPLAY AVG, COS, COP
• 240 END

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Original Pseudocode
New Program Code

• ACCEPT SCR
• 110 IF SCR 999
• 120 GOTO 220
• 130 ELSE
• 140 COMPUTE SOS SOS SCR
• COMPUTE COS COS 1
• 160 IF SCR gt 60
• COMPUTE COP COP 1
• 180 ELSE
• 190 ENDIF
• GOTO 100
• 210 END-IF
• COMPUTE AVG SOS / COS
• 230 DISPLAY AVG, COS, COP
• 240 END

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 gt 60
Compute COP COP 1 EndIf Endif Go to
Top of Program
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High-Level Language to Machine Code
COMPUTE C A B
High-Level Language
Compilers Interpreters -Translators
LDA A MPY B STA C
11011010010010001010101001
Assembler Language
Machine Language
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Go TU !!!