CSC 170 – Introduction to Computers and Their Applications, Lecture notes of Introduction to Computers

Download CSC 170 – Introduction to Computers and Their Applications and more Lecture notes Introduction to Computers in PDF only on Docsity! 1 CSC 170 – Introduction to Computers and Their Applications Lecture #4 – Digital Devices Computers • At its core, a computer is a multipurpose device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions. • Input is whatever is typed, submitted, or transmitted to a computer. • Output is the result produced by a computer. 2 Computers • Computers process data by performing calculations, modifying documents and pictures, drawing graphs, and sorting lists of words or numbers. • Processing is handled by the computer’s central processing unit (CPU). Computers 5 Computers • Application software is a set of computer programs that helps a person carry out a task. • The primary purpose of system software is to help the computer system monitor itself in order to function efficiently (an example of system software is a computer operating system or OS). • Development tools are used for creating software applications, Web sites, operating systems, and utilities. Circuits and Chips • The small circuit boards and integrated circuits you see when you open up a digital device are the essence of digital electronics • Digital electronics represent data bits as electrical signals that travel over circuits in much the same way that electricity flows over a wire when you turn on a light switch 6 Circuits and Chips • An integrated circuit (IC) is a set of microscopic electronic circuits etched onto a thin slide of semiconducting material • The terms computer chip, microchip, and chip are commonly used to refer to integrated circuits • Semiconductors, such as silicon and germanium, are substances with properties between those of a conductor (like copper) and an insulator (like wood) Circuits and Chips 7 Circuits and Chips • The electronic components of most digital devices are mounted on a circuit board called a system board, motherboard, or main board. • The system board houses all essential chips and provides connecting circuitry between them. Circuits and Chips 10 Enterprise Computers • The most powerful computers are generally used in businesses and government agencies • These computers have the ability to service many simultaneous users and process data at very fast speeds • Types of “Big” computers are: – Supercomputers – Mainframes – Servers Enterprise Computers • Supercomputers - considered the fastest computers in the world at the time of construction; can tackle complex tasks other computers cannot; typical use includes breaking codes, modeling weather systems, and simulating nuclear explosions. • Mainframes - a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users; looks like a closet-sized cabinet; used to provide centralized storage, processing, and management for large amounts of data. • Servers - “serves” data to computers in a network; Google search results are provided by servers; about the size of a desk draw and mounted in racks of multiple servers. 11 Personal Computers • A personal computer is designed to meet the computing needs of an individual • The term personal computer can be abbreviated as PC • Personal computers can be classified as: – Desktops – Portables – Laptops – Tablets – Smartphones Personal Computers • Desktops - fit on a desk and run on power from a wall outlet; keyboard is typically separate from the monitor; popular in offices and schools • Portables - run on battery power; their components are contained in a single case for easy transportation • Laptops - also referred to as a notebook computer; small and lightweight with a clamshell design and keyboard at the base 12 Personal Computers • Tablets - a tablet computer is a portable computing device featuring a touch-sensitive screen used for input and output; uses a specialized OS; a slate tablet configuration has a narrow frame screen that lacks a physical keyboard; Apple iPad is a slate tablet • Smartphones - mobile devices with features similar to a tablet computer; provide telecommunications capabilities over cell phone networks Niche Devices • Niche devices all have one thing in common: They contain a microprocessor • Raspberry Pi -Just a tad larger than a deck of cards; the Raspberry Pi can be connected to a keyboard and screen for a full computer experience • Portable media players - are handheld devices that can store and play music; iPod touch is a portable media player 15 Choosing a Digital Device • Computers that operate essentially the same way and use the same software are said to be compatible or having the same “platform.” • You can assess whether two computers are compatible by checking their operating systems. Choosing a Digital Device • Prices for digital devices can vary and depend on screen size, microprocessor size, and memory: – The price tag for a smartphone is $200–$900 – Tablet computer prices range from $200 and $1,200 – Desktop and laptop computers usually cost a little more, with price points roughly grouped into three categories: • Above $1,200 • $500 – $1,200 • Under $500 16 Choosing a Digital Device • Computer ads are loaded with jargon and acronyms, such as RAM, ROM, GHz, GB, and USB. Microprocessors • A microprocessor is an integrated circuit designed to process instructions. • It is the most important, and usually the most expensive, component of a digital device. • Intel Corporation is the world’s largest chipmaker and supplies a sizeable percentage of the microprocessors that power desktops and laptops. 17 Microprocessors • Intel’s 8086 family of microprocessors powered the original IBM PC. • The 8086 chip family set the standard for processors used today. • This standard is sometimes referred to as x86. • Processors found in today’s desktops and laptops are x86 compatible. Microprocessors • Processors based on ARM technology dominate tablet computers and smartphones. • ARM technology was originally designed by ARM Holdings, a British technology company founded by Acorn Computers, Apple Inc., and VLSI Technology. • ARM processors are energy efficient — an important characteristic for battery-powered devices. • ARM processors are found in Microsoft’s Surface tablets, Apple’s iPads and iPhones, and Samsung’s lineup of Galaxy phones. 20 Performance • Pipeline and parallel processing offer better performance than serial processing. Performance • What affects performance? – CPU cache (pronounced “cash”) is a special high- speed memory that allows a microprocessor to access data more rapidly – Word size refers to the number of bits that a microprocessor can manipulate at one time; it limits the amount of memory that the processor can access – A RISC (reduced instruction set computer) processor performs instructions faster than a CISC (complex instruction set computer) processor 21 Random Access Memory • RAM (random access memory) is a temporary holding area for data, application program instructions, and the operating system • Higher RAM capacity adds to the expense of a device • In RAM, microscopic electronic parts called capacitors hold the bits that represent data • Most RAM is volatile, meaning it needs electrical power to hold data Read-only Memory • ROM (read-only memory) is a type of memory circuitry that is housed in a single integrated circuit on the system board. • ROM contains a small set of instructions and data called the boot loader that tell a digital device how to start. 22 Read-only Memory • There are several reasons why you might want to change the contents of ROM and boot loader instructions, including: – Repair – User modification – Forensics – Updates