COMSCI 1100 UNIT 2 

UNIT 2.1: Computer History

Earliest Computing Tools

==Sand Tables== - known to be the earliest device for computation, it consists of three groves in the sand with a maximum of 10 pebbles in each groove

==Abacus== - derived from the Arabic word ‘abaq’ which means ‘dust’. Consists of sliding beads arranged on a rack which has two parts: upper part and lower part.

==Napier Bones== - small instrument made of 10 rods on which multiplication table was engraved. It enabled to perform multiplication and division

==Slide Ruler== - jointly devised by Edmund Gunter & William Oughtred. Based on the principle that actual distances from the starting point of the rule is directly proportional to the logarithm of numbers printed on the rule

Mechanical Era of Computers

Zeroth Generation

==Blaise Pascal== - He invented the first mechanical adding machine called Pascaline (1642)

==Baron Gottfried Wilhelm von Leibniz== - He improved Pascal’s machine

==Joseph Marie Jacquard== - He invented a loom that used punch cards to control patterns into woven cloth (1801)

==Charles Babbage== - Father of Modern Computer

• ==Difference Engine==: used to computer table of numbers using naval navigation and can only add & subtract
• ==Analytical Engine==: general purpose machine

==Herman Hollerith== - Invented one of the first commercial machine which used punch card to tabulate and process the data collected

==Howard Aiken== - He led the designing of MARK I (1937); improved Babbage’s machine; His machine was considered the first electronic machine using thousands of relays.

Electronic Era of Computers

First Generation: Vacuum Tubes (Late 1930s – Early 1940s)

==AB Computer (Atasoft Berry Computer)== - First electronic computing machine, which introduced the idea of binary arithmetic, regenerative memory and logic circuits

==Colossus== - World’s first electronic digital computer used to decode intercepted message

==John von Neumann machine== - Developed a concept of storing a program in memory.

==ENIAC (Electronic Numerical Integrator and Computer)== - Developed for calculating artillery firing tables

==EDVAC (Electronic Discrete Variable Automatic Computer)== - First electronic computer to use stored program concept

==EDSAC (Electronic Delay Storage Automatic Computer)== - Machine to run the first successful program

==UNIVAC (Universal Automatic Computer)== - First commercially available computer. First general-purpose computer which was designed to handle both numeric and textual information

Second Generation: Transistors (1940s – Early 1960s)

==Transistor== - it was invented at Bell Labs in 1947 but did not see widespread use in computers until the late 1950s

• ==Second-generation computers== moved from cryptic binary machine language to symbolic or assembly language which allowed programmers to specify instructions in words
• One of the major developments in this generation includes the progress of machine language to assembly language.

==Third Generation: Integrated Circuits (1960s – 1970s)== - This generation started using semiconductor memories, microprocessors, and multiprogramming. Another development was the use of an operating system that allowed machines to run many different programs at once with a central program that monitors and coordinates the computer’s memory

==Integrated Circuits== - it was the hallmark of the third generation of computers

• The technology allowed dozens of transistors to be mounted on a single chip together with other electronic components.

==IBM System/360 series== - Family of computers and their peripherals which are mutually compatible and all worked together

==PDP 8== - Developed by Digital Equipment Corporation (DEC). The first commercially successful minicomputer

Fourth Generation: Microprocessors (Early 1970s – Present)

==Microprocessor== - Built onto a single piece of silicon, known as chip; about 0.5 cm long and not more than 0.05cm thick

==Large Scale Integration (LSI)== - Approximately 180 transistors

==Very Large Scale Integration (VLSI)== - Approximately 275,000 transistors

==Altair 8800 (1975)== - Developed by MITS (Mirco Instrumentation Telemetry Systems). It is one of the first microcomputers

==Apple II== - One of the first highly successful mass-produced microcomputer products. Designed by Steve Wozniak of Apple Computer

==CRAY I== - A supercomputer designed, manufactured and marketed by Cray Research

==Apple Lisa (1983)== - First commercial personal computer to use graphical user interface with 1MB RAM, 12 inch black monitor, 2 5 ¼ floppy disk driver, 5MB of profile hard drive and used Motorola 680000 microprocessor

• ‘==Lisa==’ - stood for ‘Local Integrated Software Architecture’

Fifth Generation: Artificial Intelligence (Present and Beyond)

==Mega Chips== - Computers will use Super Large-Scale Integrated chips

==Parallel Processing== - Computers will use multiple processors and perform parallel processing thereby accessing several instructions at one time and working at the same time

==Artificial Intelligence (AI)== - A series of related technologies that tries to simulate and reproduce human behavior including thinking, speaking, reasoning.

UNIT 2.2: Computer System and its Components

==Computer System== - defined as general purpose information processing machine

used to troubleshoot various problems related to data processing.

• allows users to input, manipulate and store data
• a basic, complete and functional computer

Computer System Components

Two main components:

• ==Hardware== - tangible parts
• ==Software ==– intangible parts: data and programs

==Computer Hardware== - physical machine, consisting of mechanical parts and electronic circuits

Several major units:

==Central Processing Unit (CPU)== - defined as the major component of a computer. Also known as the ‘processor’ or the “electronic brain” of the computer. Consist of the electronic circuits which are necessary to perform a variety of operations on the data

==Major components of CPU==:

• Arithmetic Logic Unit

• Control Unit

• Registers

  

==Main Memory (RAM)== - where data and numerous programs are currently being executed by the CPU are stored

• contents are both temporary and volatile
• contains operating system program, application program currently in use and the data that is being processed when the computer is in use

==Secondary Memory== - provides stable storage for both programs and data in a longer period of time. Often referred to as the disk

==Disk drives== - are also known as mass storage devices because of their capacity to store relatively large amounts of data and many programs.

==Input/Output Devices== - used in getting and displaying information

Basic Computer Hardware Operations

Units that implement the ISPO function:

• ==Input unit== – inputs the data and programs for computer processing
• ==Storage unit== – stores the input data and programs
• Pro==cessing unit==  – conducts calculations on the input data and controls input

unit, storage unit, and output unit

• ==Output unit== – output the result of computer processing in a certain format

==Computer Software==  – set of computer programs and algorithms that tells the

computer what to do and how to do it.

==Three categories of Computer Software==:

• System Software
• Programming Software
• Application Software