hardware lecture notes.pdf

CSCE 101

Hardware Lecture Notes

Hardware vs. Software Hardware consists of all the machinery and equipment in a computer system. The hardware includes, among other devices, the keyboard, the screen, the printer, and the computer or processing device itself. Hardware is useless without software. All machinery and equipment in a computer system Runs under the control of software and is useless without it. Contains circuitry that allows processing Examples: Hard drive, Cd-Rom Software programs, consists of all the electronic instructions that tell the computer how to perform a task. These instructions come from a software developer in a form (such as a CD, or compact disk) that will be accepted by the computer. Also called programs; step-by-step electronically encoded instructions that tell the computer hardware how to perform a task Hardware requires software in order to know what to do or how to run Examples: Microsoft Windows, Internet Explorer

How Computers Work All computers follow five basic operations. The information below demonstrates the five primary computer operations and lists some of the associated hardware and software. Input - Whatever is put in ("input") to a computer system. Input devices include the keyboard and the mouse. Producing User information requires input data. Keyboard - converts letters, numbers, and other characters into electrical signals readable by the processor. Mouse - used to manipulate objects viewed on the computer display screen. Processing - The manipulation the computer does to transform data into information. The brain of the computer. Motherboard - The main circuit board in the computer to which everything else, such as the keyboard, mouse, and printer, attaches through connections (called ports) in the back of the computer. The processor chip and memory chips are also installed on the motherboard.

CSCE 101

Hardware Lecture Notes

Processor chip - tiny piece of silicon that contains millions of miniature electronic circuits.

RAM - Holds data before processing and information after processing, before it is sent along to an output or storage device. System unit - the box that houses the processor chip (CPU), the memory chips, and the motherboard with power supply, as well as some secondary storage devices. Storage Primary Storage - Also called memory; internal computer circuitry that temporarily holds data waiting to be processed. Memory chip - Also known as RAM chips, represent primary storage, or temporary storage; they hold data before processing and information after processing, before it is sent along to an output or storage device. Secondary Storage - devices and media that store data and program permanently, such as disks and disk drives, tape and tape drives, CDs and CD drives. Necessary for users to save work and holds computer's software. Floppy disk - Stores data on removable 3.5-inch-diameter diskettes. Hard disk - Stores billions of characters of data on a non-removable disk platter. Zip disk drive - stores data on removable floppy-disk cartridges with 70–170 times the capacity of the standard floppy.

Output Whatever is output from ("put out of")the computer system; The results of processing Monitor Takes the electrical signals from the video card and forms an image using points of colored light on the screen. Printer Produces text and graphics on paper. Video Card Converts the processor’s output information into a video signal that can be sent through a cable to the monitor. Sound Card

CSCE 101

Hardware Lecture Notes

enhances the computer’s sound-generating capabilities by allowing sound to be output through speakers. Communications allows data to be input from afar, processed in a remote area, stored in several locations, and output in other locations; extends the ability of the computer from the device, to networked devices. ex. modem, Ethernet cable Modem Sends and receives data over telephone lines to and from computers

System Software vs. Application Software Software The programs, routines, and symbolic languages that control the functioning of the hardware and direct its operation. There are two types of software – system and application. System software Helps the computer perform essential operating tasks and enables the application software to run. Application software Enables the user to perform specific tasks – solve problems, perform work, or entertain.

Custom Built vs. Prepackaged Custom Built Know what's inside Can tailor to fit needs Generally better quality Tends to be more expensive, but yields better quality Readily Assembled Easy to obtain and ready to use Usually has a system warranty Depending on the price, can generally get a good deal in terms of cost:benefit ratio

CSCE 101

Hardware Lecture Notes

Information Technology Trends Computer Development Miniaturization everything is made smaller, and less is more Speed faster speeds Affordability lower prices Communications foundation of information age Connectivity the connection of computers to one another by a communications line in order to provide on line information access and/or the sharing of peripheral devices Interactivity two-way communication, allowing the user to respond to information he/she receives and modify what a computer is doing Multimedia technology that presents information in more than one medium, such as text, pictures, video. Computers and Communications Convergence - ex. cell phone w/ digital camera Portability - ex. laptops, cell phones Personalization - ex. bank statements online

Microchips, Miniaturization & Mobility Transistor a tiny electrically operated switch that can alternate between on and off millions of times per second. The first transistors were one-hundredth the size of a vacuum tube, needed no warm-up time, consumed less energy, and were faster and more reliable. Transistors marked the beginning of a process of miniaturization that has not ended yet. Modern transistors are so small that 3 million of them can fit into half a centimeter. Microchip is a tiny piece of silicon that contains millions of micro-miniature electronic

CSCE 101

Hardware Lecture Notes

circuits. Silicon- an element widely found in sand. abundant and cheap semiconductor material whose electrical properties are intermediate between a good conductor and a nonconductor of electricity. Miniaturization Miracles Microchips, Microprocessors, & Micro-machines portability = trading off computing power and convenience in return for smaller size and weight. Experts have predicted that small, powerful, wireless personal electronic devices will transform our lives far more than the personal computer has done so far. Microchips responsible for the miniaturization that has revolutionized consumer electronics, computers, and communications. store and process data in electronic gadgets. Varieties include microprocessors, memory, logic, communications, graphics and math co-processor chips Microprocessor the miniaturized circuitry of a computer processor or CPU, the part that processes, or manipulates, data into information When used in machines other than computers, microprocessors are called micro-controllers or embedded computers. Mobility trading off computing power and convenience in return for smaller size and weight. Experts have predicted that small, powerful, wireless personal electronic devices will transform our lives far more than the personal computer has done so far.

The System Unit Binary system Consists of two digits, 0 and 1. 0 represents the electrical current being off 1 means the current is on all data and programs that are used by a computer are represented in terms of these binary numbers.

CSCE 101

Hardware Lecture Notes

Capacity is denoted by any of the following Bit each 0 or 1 is called a bit short for "binary digit." Byte 8 bits Kilobyte 1024 bytes (1000 in base ten = 1024 in base 2) Megabyte about 1 million bytes (1,048,576 bytes) Gigabyte about 1 billion bytes (1,073,741,824 bytes) Terabyte about 1 trillion bytes (1,009,511,627,776 bytes). Petabyte 1 quadrillion bytes (1,048,576 gigabytes). ASCII stands for American Standard Code for Information Interchange the binary code most widely used with microcomputers includes such characters as math symbols and Greek letters. Unicode Similar to ASCII, but can handle more characters uses two bytes (16 bits) for each character The Parity Bit can detect a data error also called a check bit an extra bit attached to the end of a byte for purposes of checking for accuracy.

CSCE 101

Hardware Lecture Notes

The Computer Case - Bays, Buttons, & Boards System Unit houses the motherboard (including the processor chip and memory chips), the power supply, and storage devices. Case the part of the system unit that is the empty box with just the power supply Bay is a shelf or opening used for the installation of electronic equipment, generally storage devices such as a hard drive or DVD drive Tower a cabinet that is tall, narrow, and deep Power Supply a device that converts AC to DC to run the computer The three principal types of power protection devices Surge protector a device that protects a computer from being damaged by momentary surges (spikes) of high voltage. Voltage regulator a device that protects a computer from being damaged by insufficient power – "brownouts" or "sags" in voltage. UPS (uninterruptible power supply) a battery-operated device that acts as a surge protector and provides a computer with electricity if there is a power failure.

The Motherboard & Microprocessor Chip Motherboard the main circuit board in the system unit consists of a flat board that fills one side of the case contains both soldered, non-removable components and sockets or slots for components that can be removed—a microprocessor chip, RAM chips, and various expansion cards. Expansion

CSCE 101

Hardware Lecture Notes

a way of increasing a computer’s capabilities by adding hardware to perform tasks that are beyond the scope of the basic system. Upgrading means changing to newer, usually more powerful or sophisticated versions Every microprocessor contains a system clock controls how fast all the operations within a computer take place. Run in gigahertz, MIPS, etc How the Processor or CPU Works - Control Unit, ALU, & Registers Word size number of bits that the processor may process at any one time. CPU (central processing unit) The "brain" of the computer follows the instructions of the software to manipulate data into information. The CPU consists of two parts Control unit deciphers each instruction stored in the CPU and then carries out the instruction. Arithmetic logic unit (ALU) performs arithmetic operations and logical operations and controls the speed of those operations. Registers high-speed storage areas that temporarily store data during processing. All data must be represented in a register before it can be processed. Buses electrical data roadways through which bits are transmitted within the CPU and between the CPU and other components of the motherboard.

How Memory Works: RAM, ROM, CMOS, & Flash RAM (random access memory) chips for primary storage temporarily hold software instructions and data before and after it is

CSCE 101

Hardware Lecture Notes

processed by the CPU volatile the contents are lost when the power goes off or is turned off. ROM chips to store fixed start-up instructions cannot be written on or erased by the computer user without special equipment. ROM chips contain fixed start-up instructors necessary for basic computer operations. CMOS chips to store flexible start-up instructions complementary metal-oxide semiconductor are powered by a battery and thus do not lose their contents when the power is turned off. Flash memory chips used to store flexible programs a nonvolatile form of memory can be erased and reprogrammed more than once do not require a battery Flash memory is also used in newer PCs for BIOS instructions

How Cache Works - Level 1 (Internal) & Level 2 (External) Cache temporarily stores instructions and data that the processor is likely to use frequently speeds up processing One of the few differences between different versions of the same chip Example Intel® Pentium® 4 Processor with HT† Technology Extreme Edition L2 Cache - 512KB 512KB L3 Cache - 2MB Intel® Pentium® 4 Processor L2 Cache – choice of 256KB, 512KB, 1MB

CSCE 101

Hardware Lecture Notes

L3 Cache - none 2MB There are two kinds of cache—Level 1 and Level 2 Level 1 (L1) cache—part of the microprocessor chip Faster than L2 Smaller Capacity Built into processor chip Level 2 (L2) cache—not part of the microprocessor chip – External cache Resides outside the processor Ports & Cables Port a connecting socket or jack on the outside of the system unit into which are plugged different kinds of cables facilitates communication between computer and device types Serial ports for transmitting slow data over long distances a line connected to a serial port will send bits one after another. Think older Mouse connections Parallel ports for transmitting fast data over short distances a line connected to a parallel port allows 8 bits (1 byte) to be transmitted simultaneously. Think SCSI ports for transmitting fast data to up to seven devices in a daisy chain think hard drives, cd-roms USB ports for transmitting data to up to 127 devices in a daisy chain think newer mouses FireWire ports

CSCE 101

Hardware Lecture Notes for camcorders, DVD players, and TVs developed to improve PC/peripheral connections and to compete with USB. DVD players, digital audio equipment, TVs, and gaming consoles.

Dedicated ports the back of a computer also has other, dedicated ports—ports for special purposes connect keyboard and mouse, et al Infrared ports for cable-less connections over a few feet allows a computer to make a cable-less connection with infrared-capable devices.

Expandability - Buses & Cards Expansion slots are sockets on the motherboard into which you can plug expansion cards. Expansion cards also known as expansion boards, adapter cards, interface cards, plug-in boards, controller cards, etc are circuit boards that provide more memory or that control peripheral devices. The following are the common types of expansion cards Graphics cards - for monitors Sound cards - for speakers and audio output Modem cards - for remote communication via phone lines Network interface cards - for remote communication via cable PC Cards - for laptop computers Expansion cards are made to connect with different types of buses on the motherboard.

CSCE 101

Hardware Lecture Notes

Secondary Storage Floppy Disks often called a diskette or simply a disk a removable flat piece of mylar plastic packaged in a 3.5-inch plastic case. write-protect notch prevents a diskette from being written to. tracks On the diskette, data is recorded in concentric recording bands Various types of disks available are 3.5-inch floppy disks 1.44 megabytes Zip disks—100 megabytes Hard Disks Hard disks thin but rigid metal, glass, or ceramic platters covered with a substance that allows data to be held in the form of magnetized spots head crash - occurs when the surface of the read/write head or particles on its surface come into contact with the surface of the hard-disk platter, causing the loss of some or all of the data on the disk. There are two types of hard disks Non-removable housed in the microcomputer system unit used to store nearly all programs and most data files. Removable Also known as hard-disk cartridges consist of one or two platters enclosed along with read/write heads in a hard plastic case, which is inserted into a microcomputer’s cartridge drive. Optical Disks: CDs & DVDs optical disk a removable disk usually 4.75 inches in diameter and less than 1/20 of an inch thick,

CSCE 101

Hardware Lecture Notes data is written and read through the use of laser beams

Following are the types of optical disks CD-ROM - for reading only - CD-ROM (compact disk read-only memory) CD-R - for recording on once - CD-R (compact disk–recordable) disks CD-RW - for rewriting many times - A CD-RW (compact disk– rewritable) disk DVD-ROM - the versatile video disk - A DVD-ROM (digital versatile disk or digital video disk, with read-only memory) Magnetic Tape a thin plastic tape coated with a substance that can be magnetized Data is represented by magnetized spots (representing 1s) or nonmagnetized spots (representing 0s). Old and archaic, but a good way to back-up data Smart Cards look like a credit card but contains a microprocessor embedded in it hold more information than standard credit cards—about 8–40 megabytes of data. Some can be reloaded for reuse. Optical cards are plastic, laser recordable, wallet-type cards used with an optical-card reader. Flash Memory Cards consist of circuitry on credit-card-size cards that can be inserted into slots connecting to the motherboard flash memory is nonvolatile.