CIS 1 Lecture Notes

Chapter 1 What is a computer?
The Users View of a Computer System
Application Software Operating System Software CPU & other Hardware

The Users View

What is a computer?
A computer is an electromechanical device which can be programmed to change (process) information from one form to another. Electromechanical - It runs on electricity and it has mechanical components.

The computer system

A computer system includes: 1. Hardware - the physical components which make up a computer system 2. Software (or programs) - the instructions that tell the computer what to do
The components of a computer system
Hardware Components the system unit the processor memory permanent storage devices input devices output devices Software Components system software including operating system software application software development software
The Hardware Components of a Computer System

INPUT SYSTEM UNIT OUTPUT

PERMANENT STORAGE
Examples of Hardware Components

Processing

Output

Storage

Some Simple Definitions
application software - software which lets the user accomplish a specific task like word processing, spreadsheets, or drawing pictures.
system software - software manages, controls, and maintains the computer operating system software system software which manages the overall operation of the computer system such as: Windows 95/98 Macintosh OS NeXT Linux Windows 2000 OS/2 Windows NT Be Solaris

Software

Operating System Software

Application Software

Types of computers
1. General Purpose Computers 2. Special Purpose or Dedicated Computers 3. Embedded Computers
1. General Purpose Computers computers in which the user can modify the computer system, by adding additional hardware and especially software, in order to accomplish a variety of tasks examples: supercomputers, workstations and microcomputers (PCs and Macs)
2. Special Purpose or Dedicated Computers - complete computer systems, with a specific purpose and perform only the task for which they were designed examples: Game systems such as Sony Playstation, information kiosks
3. Embedded Computers computers which are found inside consumer goods in order to enhance them examples: VCR, Cell Phone
Categorizing computers by size and function
1. 2. 3. 4. 5. Supercomputer Server Workstation Personal Computer (Microcomputer) Terminal or Computing Appliance
Some older terms: Mainframe, Minicomputer, Microcomputer

Supercomputers

IBM BlueHorizion Supercomputer at the San Diego Supercomputer Center (at the University of California, San Diego) is the 10th most powerful computer in the world.
(and the most powerful in an academic research facility.)
IBMs latest supercomputer
(for the US Dept. of Energy)
1,000 times faster than Deep Blue Its the size of two basketball courts 8,192 copper processors 6.2 terrabytes of memory
12.3 trillion calculations/second (teraflops) (translation: In one second it can solve what a human being with a calculator would take 10 million years)

Server

A Server is a machine that is designed to provide services for many people. Because it is typically more powerful than a desktop computer (in order to efficiently serve all of its clients), the term server has become synonymous with a powerful computer.
Dell PowerEdge 6450 Server (from $6,209) up to 4 processors 256MB to 8GB RAM up to 144GB storage
Workstation - A general-purpose computer designed to be used by one person at a time and which offers higher performance than normally found in a personal computer, especially with respect to graphics, processing power and the ability to carry out several tasks at the same time.
Compaq AlphaStation ES40 (~$50,000) up to bit processors up to 32GB RAM
Personal Computer A general-purpose single-user microcomputer* designed to be operated by one person at a time.
* Microcomputer a computer with a microprocessor
terminal (or Computing Appliance) a minimal computer with a connection to another computers processor, storage and other devices.
WebTV appliance Sony INT-W250 (msrp $249.99) hooks up to your TV and phone line