ACS1453 Lecture Outline 1 Prof. E. Kaluzniacky 1. The name of the course: Intro. to Computers

1. ACS1453 Lecture Outline 1 Prof. E. Kaluzniacky 1. The name of the course: Intro. to Computers - Basic workings and terms - Common productivity software - Windows - Word - Excel - Access - Powerpoint - Intro to Customized Information Systems - Internet basics

2. Introducing the Computer - one def'n: information processor capable of performing electronically substantial computations including numerous arithmetic or logical operations without intervention by a human operator - basic architecture: CENTRAL INPUT -> PROCESSING -> OUTPUT UNIT + MAIN MEMORY (internal) AUXILIARY STORAGE (external)

3. Basic Workings: The CPU: (draw this)   Control Unit: (registers) Arithmetic / Logic (accumulator) Unit: (ALU) Main Memory: (cells) (Primary Storage)

4. Into the cells in main memory we put - instructions - data for the instructions - both in electronic form Instructions for the CPU - tell it to perform sequences of very basic operations   e.g., add, subtract, multiply, divide, move, store

5. Every major problem that we want the computer to solve   - must be broken down into a series of instructions at this simple level - * these are the only kind of instructions that the computer can actually execute

6. Diagram: (sample machine level program) Instruction: opcode + address Opcodes: 008 - clear accumulator and add the contents of the following address in main memory 009 - add to the accumulator the contents of the following address 010 - store the result from the accumulator in the following address in main memory example of an instruction:   008 003

7. 008 003 008 - load into accumulator in ALU 003 - whatever is in address 3 Sample program and its data: program: memory cell 0: 008 003 1: 009 004 2: 010 005 data: Memory cell 3: 000 100 memory cell 4: 000 050 {let’s play computer}

8. example of an instruction:   008 003 However, such instructions must be represented electronically - in terms of + OR - 008 003 (base 10) 1000 0011 (base 2) +--- --++ (electronic form) - this is how an instruction looks in the machine

9. The same program in binary • 008003 1000 0011 • 009004 1001 0100 • 010005 1010 0101

10. The machine fetches, decodes, executes and stores results of the execution Bit: single digit - can be 0 or 1 Byte: 8 bits side by side (moved around & addressed as a unit) 8 bits = 1 byte Main memory capacity -> in bytes K bytes = 1024 bytes Megabyte = 1024 Ke.g., 32 MB of main memory Gigabyte = 1024 MB

11. Instructions at this level (+ and -) are said to be in machine language • Earliest programs were written in machine language (first generation language) • Then, a coding system was developed • -each character on keyboard is represented by a specific sequence of 0s and 1s (ASCII or EBCDIC – agreed upon coding schemes) • Each character represented by 1 byte of ASCII • -now programs could be written in symbolic machine language (assembly language)

12. e.g., CLA X ADD Y (second generation STO Z language) X Y Z A translation program [assembler], itself in machine language, would translate this code into actual machine language for the CPU

13. But, assembly language [second generation] - low level: - one statement in assembly language translates into - one statement in machine language A complicated, "real world" problem, still had to be broken down into small steps for the CPU  Then came third generation languages (high-level) - one statement in 3GL translates into   - many statements in machine language

14. To program a complicated problem, we do not have to think at the level of machine language (translation program [compiler or interpreter] translates 3GL to machine language) However, in a 3GL, we still have to tell the computer both WHAT to do and HOW to do it. Different 3GLs:  COBOL (business)FORTRAN (scientific) BASIC PASCAL C JAVA - each has different grammar; suited to different problems

15. Fourth generation languages: (Very high-level) - much more user-friendly - we tell computer WHAT to do but not HOW to do it (NON-PROCEDURAL) - how is a 4GL developed? (the "Averager") - only for specific problems / uses Different 4GLs: dBASE III IFPS SQL Now: non-procedural 4th generation productivity software

16. - we can also call common application software word processing spreadsheets web browsers multimedia programs as fourth generation (non-procedural) software [WHAT to do; not HOW] (software, but not language as such – uses Graphical User Interface – GUI)  Need for 3GL over 4GL:   - when no 4GL exists for this particular problem - example:

17. Hardware and Software:   - like a cassette and the song on it   - software: instructions in electronic form (programs) - data: also in "soft" form, but not called software Application and System Software: Application software: programs intended to solve problems outside of the computer itself System Software: "behind-the-scenes" programs which help the computer hardware to run

18. - most important category in system software is the Operating System e.g., DOS, Windows 7, Windows XP, Unix, Mac OS/X -tasks: - finding disk space; keeping track -allocating memory to user programs -initiating hardware circuitry - sending documents to printer other tasks: will learn in Windows xp

19. Other types of system software • - language translators • - assemblers, compilers, interpreters • - teleprocessing software • - utilities

20. COMPUTER STORAGE Primary (Internal) Storage: - main memory - contents erased when power off Secondary (External) Storage: - more permanent - magnetic disk, tape - optical storage - flash memory

21. Magnetic Disk - diskette or hard disk - platters one below other - each platter has tracks - data stored along tracks - info. picked up by read / write heads - we take software and data from disk to main memory - disk allows direct access as opposed to tape which is sequential - 1024 Megabytes = 1 Gigabyte

22. Optical Storage - laser light instead of magnetic form - can store much more data in same amount of space - may take longer to retrieve CD – can store more info than magnetic disk CD-ROM - can store encyclopedias - read only WORM, or Rewriteable optical disks

23. INPUT and OUTPUT DEVICES:   - ASCII - American Standard Code for Information Interchange   - each keyboard character is represented   by its own BYTE (8 bits) - an agreed-upon coding system   - a coding system is needed to get information into and out of a computer Input units:  - keyboard (terminal) - mouse or trackball - scanner  - see text for others

24. Output units: - printer - screen - auxiliary storage  - note others from text Classification of Computers: Supercomputers: largest, most powerful, $$$ parallel processing Mainframes: central, many dumb terminals Minicomputers: smaller mainframes Microcomputers: can be networked

25. THE MICROCOMPUTER - microprocessor is the CPU - much elaborate, user-friendly software   - system unit (box), monitor (screen), keyboard, mouse, printer In the system unit: - motherboard, disk drives, CD-ROM drive, cards, cables, power supply

26. Motherboard: - main circuit board: microprocessor (chip), RAM (Random Access memory - main memory), buses, cards - Intel chips (past and present): 8088, 8086, 80286, 80386, 80486, Pentium+++ -speed in MegaHertz (Million of vibrations per second) -all processing (calculations) done in the microprocessor

27. - RAM: main memory chips; 32MB, 64 MB .. P. - into RAM goes the Operating System, Application software, data  - ROM (Read Only Memory) – burned-in programs to start up the computer - Buses (multi-lane highways) carry instructions from memory to microprocessor and back - Cards: circuit boards that plug into expansion slots on the motherboard; - link peripheral equipment (printers, disks) with motherboard - at the back of the cards are ports - USB port: universal serial bus

28. Disk drives:  - hold the actual disks - floppy or hard - hard disk stores more info and info can be retrieved faster - before a disk is ready for storage it must be formatted by the operating system CD drives:   - compact disk- read-only memory - for CD optical disk - considerable application software is now purchased on CD-ROM Power supply:   - converts the power from the electrical outlet to power that the computer can use

29. Parts of a microcomputer outside the system unit: Keyboard:   - press key, the character's ASCII code is sent down Monitor: - CRT, VDT (video display terminal) - had CGA, EGA, VGA, Super VGA - more colors, dots closer together Printer:   - impact or non-impact - dot matrix (old) - ink jet - laser Mouse: - for use with Graphical User Interfaces (GUIs) on the screen

30. Modem: - modulator / demodulator - needed for talking to another computer by phone - changes the form of information from + and - in a computer to a continuous wave form used on a phone line and back to + and - on receiving end - can be internal or external; internal is on a card and plugs into motherboard USB port: Universal serial bus see WIN 41

31. Linking Microcomputers LAN - local area network (connect with private cable)   - data in one place for all to use - all micros can share the same software (e.g., MS Word) - all micros can share peripherals (e.g., printer) - e-mail A file server is the main microcomputer in the network; fast processor, most disk space, much memory etc.  - also has a network operating system which works on top of the individual computers' operating systems   - individual micros might run Windows 95, but the NOS is Novell Netware (or Windows NT)  Can connect networks to other networks

32. Client / server computing - a business problem is solved in such a way that some of the computing is done on the server and some on the individual (client) machines (diagram on board) Software for the Microcomputer  a. Operating System:   IBM compatible: DOS, Windows 3.1  Windows 95, 98, 2000, XP, Windows NT, OS/2, Linux Unix op. system - multi-user*, multi-tasking - *several screens & keyboards into one system unit  Apple: System 7.5, Mac OS, +++

33. b. Application Software: - non-procedural - for specific application purposes - runs under a specific operating system KEY TYPES OF SOFTWARE: 1. Word Processing - e.g., Word, WordPerfect - contain desktop publishing features 2. Spreadsheets - electronic worksheet with rows and columns   - some numbers are entered and others ar calculated through formulas   - can do "what-if" analysis: decision support   - e.g., Excel, Lotus

34. 3. Data Management Software*** - keep records of data in a file - extract records that satisfy certain conditions - sort the data, produce reports

35. 4. Graphics Software - "tables inform, graphics convince"   - high quality presentation graphics (bar, pie, line, etc.) 5. Integrated Software   - medium level wp, spreadsheet, and data management functions within one package - e.g., Microsoft Works 6. Suites   - tie together popular "stand alone" software in one umbrella (like rooms in a suite) - sold at reduced price   - e.g. MS Office: Word, Excel, PowerPoint, Access Corel WordPerfect Suite 8

36. 7. Accounting Software - electronic bookkeeping - flexible report generator - smaller business: Simply Accounting, DAC-EASY Accounting, Quickbooks - larger: ACCPAC PLUS, ACCPAC for Windows 8. Specific Industry Systems - fit the information needs of specific businesses - e.g. -manufacturing software for a window company - appointment book for a dentist's office -software to manage a golf course - such packages may connect to existing accounting software