Introduction to Computer Systems: Types and Essential Components, Slides of Introduction to Computing

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CS101 Introduction to Computing Lecture 4 Computer Systems Docsity.com During the Second Lecture … • We talked about the evolution of computers • How initial computers were mechanical, and then came electro-mechanicals, then tube-based, and finally transistor based, and how the future belongs to quantum computers • We discussed how the size is drastically decreasing with time and how their capability is increasing year by year Docsity.com Supercomputers (1) • State-of-the-art machines designed to perform calculations as fast as the current technology allows • Used to solve extremely complex and large-scale problems: weather prediction, simulation of atomic explosions; aircraft design; movie animation • Cost tens of millions of dollars • Unique in that unlike mainframes & personal computers, designed to focus all their resources and capabilities on a single task at a time Docsity.com Supercomputers (2) • Early supercomputers used a single or a few processors working in parallel • Those processors were custom-built for the supercomputers, and were, therefore, very expensive • Modern supercomputers use the same processors that are used in desktop PCs. They, however, are designed to use 1000’s of them working together in parallel Docsity.com Why use many not-so- powerful processors working in parallel Why not just design a single, really powerful processor Post your answers on the CS101 message board ? ? Docsity.com Mainframe Computers (2) • Designed for very-high reliability • Can be serviced/upgraded while in operation • Generally consist of multiple processors, GB’s of memory, and TB’s of storage • Cost in millions of dollars Docsity.com Servers/Minicomputers (1) • The name minicomputers used to define the class of computers that lies between personal computers and mainframes • Then very high-end desktop computers – called low-end or mid-range servers – took over the role that was previously played by minicomputers Docsity.com Servers/Minicomputers (2) • Low-end and mid-range servers are used by small businesses and organizations as file-stores, to run e-mail systems and Web sites • Generally are more reliable than desktops, but not as solid as the mainframes • Generally consist of 2 or more processors, GB’s of memory, and TB’s of storage • Costs in hundreds of thousands of dollars Docsity.com Mobile Computers (1) • Laptops, palmtops, and wearable computers are very capable computers but are light-weight and consume very little power • Laptops (also called notebook computers) generally weigh around 2kg, use special low-power processors, typically have 256MB memory, 40GB of storage, can work for more than 2 hours on battery • Their usage is similar to that of PCs • They cost in the range of $1500-2500 Docsity.com Mobile Computers (2) • Palmtops, also known as PDA’s - Personal Digital Assistants • Weigh less than a pound, have very low-power processors, KB’s of memory, MB’s of storage capacity • Can run for many hours on AA batteries • Used as an electronic version of a pocket diary. Also for Web surfing and e-mail or even as mobile phones • Palmtops cost $200-600 Docsity.com Mobile Computers (3) • Wearables are small in size, carried in a pocket, worn on the arm, waist, or head or elsewhere on the body • Capability similar to PDA’s, but more expensive • They are always ON, and always accessible. That is, the user can always enter and execute commands, even while walking around or doing other activities • Each soldier of the future will be fitted with one Docsity.com At the highest level, two things are required for computing Hardware: The physical equipment in a computing environment such as the computer and its peripheral devices (printers, speakers, etc.) Software: The set of instructions that operates various parts of the hardware. Also termed as “computer program” Docsity.com We’ll have a lot to say about software during the duration of this course However, for the rest of today’s discussion, let’s concentrate on hardware Docsity.com All computers have the following essential hardware components: Input – the component through which a user instructs a computer about what to do Processor – the engine that processes the instructions given by the user Memory – where the processor stores information that is required during its computations Storage – where information that is required to be used much later is stored Output – the component that communicates the results of a computation to the user Docsity.com Keyboard Mouse Printer Memory Hard Disk Memory Bus System Bus Monitor Compact Disk Processor Integer Unit Control Unit Cache Memory Floating Point Unit Docsity.com Input Devices ¢ Mouse Keyboard Joystick * Camera ¢ Microphone * Scanner Docsity.com What’s a Docsity.com Processor • Pentium • Celeron • Athlon • PowerPC • StrongARM (PDA) • Crusoe (Laptops) • SPARC (Workstations) Docsity.com Memory/Storage • RAM • Punch cards • ROM • Hard disk • Floppy disk • Tape • CD • DVD Docsity.com Classifying Memory/Storage • Electronic (RAM, ROM) magnetic (HD, FD, Tape), optical (CD, DVD) • Volatile (RAM), non-volatile (HD) • Direct access (RAM, HD), serial access (Tape) • Read/write (HD, RAM), read-only (CD) Docsity.com modem Docsity.com modulator emodulator o m d e m Docsity.com Modem is an example of a device that acts both as an input as well as an output device • Can you think of any other such dual- purpose devices? – Network cared – Touch screens Docsity.com