Mainframes vs. PCs: Understanding the Evolution and Differences in Computing

1. Intel and the microprocessor Module1 – Section2

2. Mainframes vs. PCs • Speaking about computers during this course  personal computers (PCs) • Before PCs, computers meant  mainframes • Let us compare between mainframes and PCs.

3. Mainframes • Housed in special air-conditioned rooms!  need special care • Carryout different tasks for several people simultaneously  not intended for personal use • Operated only by specialists • Very expensive  millions! • Sold in small numbers

4. Mainframes • Had software based on the costumer needs • Maintenance (machine and software) is a major task done by the manufacturing company • The customer-supplier relationship is long-termed • Majority of mainframes supplied and serviced by IBM

5. PCs • Cheap  1,000$ or less! • Operated directly by anyone (specialist or non-specialist) • Sold in huge numbers • Utilize commonly available software • replaced frequently  maintenance is very rare!

6. PCs • Customer-supplier relationship is short-termed (terminated after selling the machine ) • Many companies sell PCs: IBM, Dell, Compaq, Acer… etc.

7. History of computer development • Automation was a target for many people long time ago • The two factors that made it urgent: • Second world war • Growth of office-based work • The Godfathers of computing are: • Charles Babbage • Alan Turing • John Von Neumann

8. Difference Engine • Designed by Charles Babbage (engineer, mathematician and philosopher) in 1822 • A device to calculate navigational tables • Ridden with errors introduced through manual calculations • A small but incomplete working model was built • Acted as a special purpose calculator

9. Analytical Engine • Designed also by Charles Babbage • General purpose device • Performs arithmetic and logic functions • Instructions were fed by punch cards, and kept in a store( computer’s memory) • Resembled today’s computers • Wasn’t completed

10. Turing Machine • Designed by Alan Turing (mathematician) in 1936 • It was a general purpose mechanical device, outlined in a paper, he wrote. • Receives basic instructions from a tape stream • Proved that not all mathematical problems can be solved!

11. Turing Machine • It was the basis of computers • Alan Turing did the following: • Worked on deciphering messages composed by Enigma coding machine • Was the founder of Artificial Intelligence (can machines think?)

12. ENIAC • Stands for: Electronic Numerical Integrator and Computer • Designed by John Mauchly and Presper Eckert • A project based at the University of Pennsylvania • First large-scale computer

13. ENIAC • Used vacuum tubes • instead of electromechanical relays used in other computing devices • faster • Perform the same task as transistors • Switch their states (on or off) • Capable of performing complex calculations • Required during the war

14. ENIAC • Was still limited • Had very little memory • Reprogramming it (telling it to perform certain task) was too difficult • To overcome its limitations design EDVAC, its successor • It was still being completed!

15. EDVAC • Stands for: Electronic Discrete Variable Automatic Computers) • Designed by John Von Neumann (mathematician and intellect) • Had a stored programmable memory • Contained both instructions and data the computer required • EDVAC structure resembled the modern computer architecture

16. EDVAC • Included: • Central arithmetic unit • Control unit • Memory • Input and output units • For this reason, modern computers are referred to as ‘Von Neumann machines’

17. UNIVAC • Designed by John Mauchly and Presper Eckert • After splitting up the company with Von Neumann • It was an EDVAC type computers for data processing • Received publicity after predicting the victory of Eisenhower in the presidential election

18. Mainframes • Manufactured by IBM • The largest suppliers of electromechanically office equipments • Calculating machines • Punch card machines • Data processing computers • Model 702 • Model 650

19. Mainframes • They were the competitors of UNIVAC • Expensive  $1 million • Most companied rented rather than bought them

20. The microprocessor • Computing, at its lowest level, is the control of data represented by 1s and 0s • Turning switches on or off • Microprocessor allows switching to occur at a very high speed • Using millions of switches (transistors)

21. The microprocessor • Ante-microprocessors: • Different functions done by different circuits • Integrated circuits: • Several functions could be performed by a single silicon ship • Reducing the size and increasing the speed of computers • Microprocessor is a programmable IC • Setting the switches in a certain manner tells the microprocessor to perform certain task

22. Main tasks of a microprocessor • Read and write to computer’s memory • Manipulate information • Microprocessor has its own set of instructions • Allow it to interpret the instructions it receives from the memory • Communicate with other parts of the computer • Coordinator role • Mainly done by the control unit

23. Instructions and languages • Microprocessor has its own basic set of instructions • Provides building blocks for computer’s functions • Written in machine language • To program a microprocessor, we use: • Assembly language (low level) • High level languages

24. Instructions and languages • Assembly language: • Different than English  difficult! • Lots of code to do a small task • the programmer must be very familiar with the exact working of the computer (its instruction set), in order to use it • High level languages: • Very close to English  easy to master • One line of code to accomplish certain task • No need to be aware of the computer’s instruction set

25. Instructions and languages • Example (comparison between assembly and BASIC languages): • To print a document: • BASIC uses the command “PRINT” • Assembly uses number of commands: • Fetch the file from a specific place in memory • Send it to the appropriate part of memory ready for printing • Send it to the printer

26. Computer’s functions and operations • Basic instruction set of a microprocessor consists of two main functions: • Arithmetic • Simple arithmetic (addition, subtraction, multiplication and division) • Complex functions are composed of the simple ones • Logic • Computer can perform tests and carryout appropriate action • IF, THEN and ELSE are used to perform the test • AND and OR are used to combine many conditions in the same test

27. Computer’s functions and operations • Number of transistors   the microprocessor can perform more functions • Example: • To convert a denary number to an octal number • A special piece of software was needed in the past • Now a days, this function is built-in to the hardware of the computer • Can be done more quickly • It’s called ‘hard-wired’ function

28. Moore’s Law • Gordon Moore: a computer scientist • Number of transistors that can be placed on the same area of a microprocessor doubles every eighteen months • The power doubles every eighteen months • The price is fixed

29. Implications of Moore’s Law • the computers will become increasingly powerful • microprocessors become cheaper • Cheap microprocessors can be placed in many products with pre-programmed functions • These are called micro controllers • Appliances having intelligence • Washing machines • Video cassettes • Recorders • Etc

30. Implications of Moore’s Law • Storage capacity falls in price by 20% per year • 5 gigabytes this year  6 gigabytes next year with the same price • Cheap storage and effective processing of information • Constant change for the computer user • No need to upgrade or maintain  by a new one! • Better features, more powerful, with the same price (or maybe less!)

31. Fairchild semiconductor: the predecessor of Intel • Established by Bob Noyce and Gorden Moore • They invented ICs • Coating a layer of oxide over silicon to connect transistors • No need to use tiny wires to connect transistors any more • This was the sole way to combine circuits on one piece of silicon

32. Intel • Established by Bob Noyce and Gorden Moore • Andy Grove joined next! He is the CEO (Chief Executive Officer) • It was one of the first technological start-up companies, which set the trend for the current computer industry • Initially produced SRAM and DRAM • Forms of computer memory

33. The Microprocessor • It was designed by Ted Hoff (initiated), but produced by Federico Faggin (realized) • The idea: • Raised from the calculator design • Instead of having many different circuits, each with hard-wired function, one general purpose circuit could be used to perform all the functions… by programming! • Changing the set of instructions to perform different task • It is simply a programmable IC • 4004, 8008, 8080, 80286, 80386, 80486, Pentium… etc

34. Exercise: evaluating web resources • Read it thoroughly! Important to solve TMA01 • Read TMA01 • Cut-off date: April 9th 2005

35. Summery • The important contributions made by Babbage, Turing, Von Neumann, Mauchly and Eckert. • How Intel was Started • How the microprocessor works • The role of microprocessor in the computer • Moore’s Law • The implications of Moore’s Law