Business Programming I Fall – 2000 By Jim Payne

Lecture 01Jim Payne - University of Tulsa2 Links: Early History of Computers Virginia Tech – History of Computing Virtual Museum of the United Kingdom Smithsonian Museum - Computers

Lecture 01Jim Payne - University of Tulsa3 History of Computing Devices Ancient Counting Devices notches, knots, pebbles, stone counting tablets Napier’s Bones and Gunter’s Slide Rule Charles Babbage – Grandfather of Computing Hollerith’s Tabulating Machine Howard Aiken’s – Harvard - MARK I

Lecture 01Jim Payne - University of Tulsa4 The Electronic Revolution John Atanasoff and Clifford Berry Iowa State University – The ABC Machine (1 st fully electronic computer) Father of Modern Computing The ENIAC – Mauchly / Eckert VonNeumann’s Contributions The UNIVAC - Remember 1951, 1952, 1954

Lecture 01Jim Payne - University of Tulsa5 Electronic Computers Generations of Computers First Generation – Vacuum Tubes 1950’s Second Generation – Transistors 1959 Third Generation - Integrated Circuits 1964 Ted Hoff, Mazor, and Fagin develop the Intel 4004 microprocessor “Computer on a Chip” It could process 60,000 instructions per second - $300 Fourth Generation - LSIC’s Large Scale Integrated Circuits 1971

Lecture 01Jim Payne - University of Tulsa6 Types of Programs Operating Systems Windows, System 8, Unix Utility Programs Scandisk, Sorting, Virus Scanner Application Programs MS-Word, MS-Excel, Payroll Program in COBOL

Lecture 01Jim Payne - University of Tulsa7 Types of Languages Machine Languages Assembler Languages INPA MPY B STA C OUTC High Level Languages FORTRAN, COBOL, PASCAL, C, JAVA, VISUAL BASIC

Lecture 01Jim Payne - University of Tulsa8 History of Languages Charles Babbage – 1833 Difference Engine Analytical Engine Babbage’s Model Difference Engine Link: Babbage biography

Lecture 01Jim Payne - University of Tulsa9 Babbage’s Model INPUT OUTPUT PRIMARY MEMORY CONTROL UNIT ARITHMETIC UNIT PROBLEM: ANSWER = A + B * C

Lecture 01Jim Payne - University of Tulsa10 Babbage’s Model PRIMARY MEMORY CONTROL UNIT ARITHMETIC UNIT PROBLEM: ANSWER = A + B * C A,B,C A = 3 B = 4 C = 2 ANSWER ANSWER = 14 or 11 ?

Lecture 01Jim Payne - University of Tulsa11 Order of Operations Rules If parentheses are present, resolve them first (then or otherwise) Precedence Rules: Exponentiation First Multiplication & Division Equal Precedence Addition & Subtraction Equal Precedence (items of equal precedence – left to right)

Lecture 01Jim Payne - University of Tulsa12 Babbage’s Model 3,4,2 Mem: CU: AU: PROBLEM: ANSWER = A + B * C A3B4 C2 INP A,B,C

Lecture 01Jim Payne - University of Tulsa13 Babbage’s Model 3,4,2 Mem: CU: AU: PROBLEM: ANSWER = A + B * C A3B4 C2 4 LDA B

Lecture 01Jim Payne - University of Tulsa14 Babbage’s Model 3,4,2 Mem: CU: AU: PROBLEM: ANSWER = A + B * C A3B4 C2 4 MPY C 4 8

Lecture 01Jim Payne - University of Tulsa15 Babbage’s Model 3,4,2 Mem: CU: AU: PROBLEM: ANSWER = A + B * C A3B4 C2 8 ADD A 11 ADD A 8

Lecture 01Jim Payne - University of Tulsa16 Babbage’s Model PROBLEM: ANSWER = A + B * C 3,4,2 Mem: CU: AU: A3B4 C2 11 STA D D11

Lecture 01Jim Payne - University of Tulsa17 Babbage’s Model 3,4,2 Mem: CU: AU: A3B4 C2 PROBLEM: ANSWER = A + B * C D11 OUT D

Problem: A + B * C Inputs: A,B,C Program: INPA,B,C LDAB MPYC ADDA STAD OUTD INPUTS: OUTPUT: ACCUMULATOR: 3,4,

Lecture 01Jim Payne - University of Tulsa19 Contribution by Babbage’sAssistant Augusta Ada - Countess of Lovelace (Lord Byron’s daughter) She suggested that if they could ever get the Difference Engine or the Analytical Engine to work for three values of A,B, and C then a simple GOTO statement could cause the “program” to work over and over. “LOOPING” For this contribution, Ada of Lovelace is often called the world’s 1 st Programmer. Link to biography

Problem: A + B * C Inputs: A,B,C Program: INPA,B,C LDAB MPYC ADDA STAD OUTD INPUTS: OUTPUT: ACCUMULATOR: 5,5,

Problem: (A + B) * C Inputs: A,B,C Program: INPA,B,C LDAA ADDB MPYC STAD OUTD INPUTS: OUTPUT: ACCUMULATOR: 5,5,

Problem: (A + 2) – (B+C) Inputs: A,B,C Program: LDAA ADC2 STAT1 LDAB ADDC STAT2 LDAT1 SUBT2 STAD OUTD INPUTS: OUTPUT: ACCUMULATOR: 7,3,

Lecture 01Jim Payne - University of Tulsa23