Lecture 2: Hardware (39 slides)

Lecturer:

Prof. Anatoly Sachenko

Information technology

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Lecture Overview

Central Processing Unit Memory Input Devices Output Devices Input/Output Devices Storage Devices

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Central Processing Unit

Central processing unit (CPU) is a basic component of computer It’s running the arithmetic and Boolean

operations, program , controlling a computational process, and co-ordinating work of all computer devices

CPU contains:ALUCUData bus and addresses busRegistersPrograms counter (continued on next slide)

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Cache — very rapid memory of small volume (8-1024 Kb)

Mathematical co-processor for the floating point numbers

ALU - is that one part of processor where the commands are running

CU - is another part of processor running the controlling functions

Registers - a row of the specialised additional memory cells

Trigger - the basic element of register is an electronic chart, which is able to keep one binary number (digit of binary code)

Central Processing Unit (continued)

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Modern processors are executed as microprocessors Physically a microprocessor is the integrated

circuit — thin rectangular form crystalline silicon lamina by an area only a few square millimeters where the blocks are placed on realizing all processor’s functions

Part of its digits is used for operation code storing, other — for storage of the operands addresses codes

Register types:Adder is a register of ALU partaking in

each operation running ( see next slide)(

Central Processing Unit (continued)

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Command counter is the CU register which corresponds to an address of next running instructionIt serves for the automatic selection of the

program from successive memory cells Command register is the CU register for

command code storing on the period of time, necessary for its completion

Microprocessor is a programmable digital electronic component that incorporates the CPU functions on a single semiconducting integrated circuit (next slide)

Central Processing Unit (continued)

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One or more microprocessors typically serve as the CPU in a computer system, embedded system, or handheld device

Central Processing Unit (continued)

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Memory – How it Builds?

Computer memory consists of the binary storage elements — bits, incorporated in groups for 8 bits which are named bytes

All bytes are numbered The number of byte is named as its address Bytes can be united in cells which are named also

words For each computer a certain word capacity is fixed

as the two, four or eight bytes

(continued in the next slide)

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It does not eliminate the use of memory of other length cells (for example, half-word, double word)

One integer or one command can be presented in one computer word

The variable formats of information presentation are assumed

Breaking up of memory on words for four-byte computers is presented in a table below:

Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 HALFWORD HALFWORD HALFWORD

HALFWORD WORD WORD

DOUBLE WORD

Memory – How it Builds? (continued)

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RAM (Random Access Memory) is a rapid data storage with not large volume It is direct-coupled with a processor and

intended for a writing, reading and storing of the programs and processed data

This memory is used for the temporal storage of data and programs only because all data in RAM disappear when a machine is turned off

There is a direct access to a RAM, it means that each memory byte has own individual address

Usual capacity is 32…512 Mb

Memory - RAM

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RAM is implemented in a semiconductor storage

It takes the form of integrated circuits It allows the stored data to be accessed in any

order — that is, at random and without the physical movement of the storage medium or a physical reading head

Key benefit of RAM over types of storage which require physical movement is that retrieval times are short and consistent Short because no physical movement is

necessary (continued on the next slide)

Memory - RAM (continued)

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Consistent because the time taken to retrieve a piece of data does not depend on its current distance from a physical head

It requires practically the same amount of time to access any piece of data stored in a RAM chip

Memory - RAM (continued)

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Cache or scratchpad memory is a very rapid memory of small volume It is used for an exchange information

between a microprocessor and main memory for difference indemnification in speed of information processing by processor and by less fast-acting main memory

Cache-memory is managed by Controller It analyses a running program trying to

foresee what information and commands are needed to the processor in the nearest time

Memory - Cache

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Cache-memory is implemented by the microcircuits of static memory of SRAM (Static RAM) It’s characterized by faster performance and

less capacity than Dynamic RAM(DRAM ) or synchronous RAM (SDRAM)

Read Only Memory (ROM) is a memory for reading only It depends on power supply, and it’s used for

storage data that will never demand a change Its content is "sewn" up specially into a device

during its manufacturing for permanent storage

Memory- Cache & Special Memory(Continued)

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It is mainly used to distribute firmware - software that is tied very closely to a specific hardware

Modern semiconductor ROM chips are not immediately distinguishable from similar chips like RAM modules

RAM chips can be read faster than most ROMs Writing speed is always much slower than

reading speed Flash Memory is a memory that depends on power supply

and assumes the frequent rewriting It’s included a BIOS (Basic Input/Output System)

Memory - Special Memory (continued)

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BIOS (Basic Input/Output System) is an aggregate of the programs intended for the automatic devices testing after plugging computer and OS loading into main memory

CMOS RAM is the memory with a low fast-acting and minimum energy consumptionIt is used for data storage about computer

equipment configuration as well as its mode of operation

Video memory (VRAM) is a variety of RAM, where the coded images are savedIt is organised so, that its content is

accessible at once to two devices: processor and display

Memory - Special Memory (continued)

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Input devices

Input device is a hardware mechanism that transforms data into external world for consumption by a computer

A computer keyboard is a device for the data input into computer and managing signals serving

It contains the standard set of the printing-press keys and some additional keys — managing and functional buttons, cursor control keys and small digital keyboard

Manipulators (mouse, joystick and other) are the special devices which are used for cursor control

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Joystick is ordinary bar-pen

Deviation from its vertical position leads to the movement of cursor in the proper direction within monitor screen

It is often used in computer games Mouse is a pointing device by detecting two-

dimensional motion relative to its supporting surface

The mouse's motion typically translates into the motion of a pointer within display

Input devices (continued)

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Touchscreens are the display overlays which have the ability to display and receive information on the same screen The effect of such overlays allows a display

to be transformed in the input device removing the keyboard and/or the mouse as the primary input device

A touchpad is an input device used commonly in laptops They are used the motions of the user’s

finger They are a substitute for a computer

mouse

Input devices (continued)

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Scanner is a device that analyzes the images and printed text and handwriting, and converts it into a digital image

Webcams are small cameras, whose images can be accessed using the World Wide Web, instant messaging, or a PC video conferencing application

Example: Skype application A microphone is an acoustic to electric transducer or

sensor that converts sound into an electrical signal

Example: Skype application

Input devices (continued)

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Output Devices

Output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world

A video adapter is a electronic board processing the video data and controlling a monitor It sends the rays brightness management

signals and sync signals of string and skilled involutes in a monitor

Monitor will transform these signals in visualisations

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Computer Display Monitor is a piece of electrical equipment which displays viewable images generated by a computer without producing a permanent record

Monitors types: cathode-ray tube based monitors liquid crystal displays touch screens

There are the graphics adapters like SVGA , SXGA , UXGA , VGA , video memory , XGA

Output Devices - Monitors

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Loudspeaker, speaker, or speaker system is an electromechanical transducer that converts an electrical signal into sound

The term loudspeaker can refer to individual devices (or drivers), and complete systems consisting of an enclosure incorporating one or more drivers and additional electronics

A printer is a printing unit which carries out a conclusion from the computer of the coded information as paper-lists of text or graphic arts

There are some kind of the printers (next two slides)

Output Devices (continued)

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Matrix printers are used by combinations of little pins that press, due to what there is a character imprint on a paper Every character, printed on a printer, is

formed from a set 9, 18 or 24 needles, formed as a vertical column

The lacks of these inexpensive printers are their noisy work and low print quality

Laser printers work approximately similarly, as copiers Computer forms in the memory

"appearance" of text page and sends to it the printer

Output Devices - Printers

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Ink-jet printers are generated by characters as a sequence of inks points( see next slide) The printer plotting head has tiny nozzles

through which inks are put on a page These printers demanding to paper quality The colored ink-jet printers are created by

colors Plotter is a vector graphics printing device that connects to

a computer They can draw complex line art, including

engineering drawing, architecture plans, geography and meteorology maps but do so very slowly because of mechanical movement of pens

Output Devices - Printers

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Output Devices – Ink - jet printer

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Input/Output Devices

Input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world – possibly a human, or another information processing system

Inputs are the signals or data received by the system, and the outputs are the signals or data sent from it

For example keyboards and mouses are considered input devices of a computer, while monitors and printers are considered output devices of a computer

Devices for communication between computers, such as

modems and network cards, typically serve for both input and output

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Storage Devices – Floppy Discs

Data storage device is a device for recording (storing) information (data)

Floppy disk is a data storage device that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell

Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be confused with "fixed disk drive", which is another term for a hard disk drive

It’s used for media conversion from one computer on other and for software distribution

The method of binary Info record on a magnetic environment is named the magnetic encodingMagnetic domains in an environment line

up along paths in the direction of the attached magnetic field by the poles of north and south

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Storage Devices – Zip Disc

The Zip drive or Zip disc is a medium-capacity removable disk storage system, introduced by Iomega in late 1994 Originally it had a capacity of 100 MB, but

later versions increased this to first 250 MB and then 750 MB

The format became the most popular of the super-floppy type products but never reached the status of a quasi-standard to replace the 3.5-inch floppy disk

It has been superseded by flash drive systems as well as rewritable CDs and DVDs, and is practically not in use anymore

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Storage Devices – Data Cartridges Magnetic tape has been used for data storage for over 50 years Modern magnetic tape is most commonly packaged in

cartridges and cassettes The device that performs actual writing or reading of data is

a tape drive Autochangers and tape libraries are frequently used to

automate cartridge handling When storing large amounts of data, tape can be substantially

less expensive than disk or other data storage options. Tape storage has always been used with large computer

systems. Modern usage is primarily as a high capacity medium for

backups and archives As of 2007, the highest capacity tape cartridges (DLT-S4,

LTO-4, SAIT-2) can store 800 GB of data without using compression

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CD-ROM is (an abbreviation of "Compact Disc read-only memory") is a Compact Disc that contains data accessible by a computer

While the Compact Disc format was originally designed for music storage and playback, the format was later adapted to hold any form of binary data

CD-ROMs are popularly used to distribute computer software, including games and multimedia applications, though any data can be stored (up to the capacity limit of a disc)

Some CDs hold both computer data and audio with the latter capable of being played on a CD player, whilst data (such as software or digital video) is only usable on a computer (such as PC CD-ROMs

These are called Enhanced CDs which are also known as CD Extra and CD Plus that combine audio and computer data for use in both compact disc and CD-ROM players

Storage Devices – CD-ROM

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Capacity of CD achieves 780 Mbytes Information is inflicted on a disk at its

manufacturing and can not be changed Changing СD-ROM technology, DVD goes swiftly

DVD has the same size like CD, but it contains up to 17 Gb i.e. one volume replace 20 standard disks of CD-ROM

Compact Disk Recordable - is capable, along with reading of ordinary compact disks, to write down information on the special optical disks It has capacity 650 Mbytes

Storage Devices – CD-ROM (continued)

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Hard Disk Drive (HDD) commonly referred to as a hard drive, hard disk or fixed disk drive, is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces

Early HDDs had removable media; however, an HDD today is typically a sealed unit with fixed media

Non-volatile memory NVM or non-volatile storage is computer memory that can retain the stored Info even when not powered NVM examples include read-only

memory, flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy disk drives, and magnetic tape), optical disc drives, and early computer storage methods such as paper tape and punch cards

Storage Devices – Hard Disc Drive

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Unlike a diskette, a hard disk is revolved continuously

It’s provided with a built-in cache - 8 MBytes which promotes their productivity substantially

Storage Devices – Hard Disc Drive (continued)

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Storage Devices – Hard Disc Drive (continued)

HDD has a very large capacity: from 40 to 750 Gb. At modern models speed of arbor (rotary-type billow) rotation makes 7200 rpm usually, mean data retrieval time is 9 ms, middle data rate up to 60 Mb/c

There are the external hard discs as above and the internal oneFor example the Internal hard discs can be

implemented as a part of the embedded systems

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Storage Devices – Internal Hard Disc

Internal Hard Disk Drive (IHDD) is the same HDD, but it is portable and connected to computer with use of USB port - Universal Serial Bus: a standard for connection sockets on computers and other HW

Example: with the MaxConnect IHDD mounting solution, a G5 Power Mac can house a total of nine disk drives internally, which enables the system to boot from one drive and allows the rest of the disk drives to be RAIDED -Redundant Array of Inexpensive Disks

It offers 8X speed increase in the data transfer rate compared to single G5 Power Mac

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Comparison of Storage Devices

Storage type

Capacity Speed Cost $

Internal Hard Disk

160 GB – 1 TB

1.5 Gb/s – 3 Gb/s

50-500

External Hard Disk

20 GB- 500 GB

4800 Mb/s (USB 2.0) 786 Mb/s (Firewire 1394)

100-300

Zip Disk 250 MB – 750 MB

2.1 Mbit/s – 133 Mbit/s

50-150

CD-ROM 700 MB 2.1 Mbit/s – 133 Mbit/s

15-20

Data Cartridges

128 MB- 16 GB

4800 Mb/s (USB 2.0)

20-340

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Storage Devices – Disc Formatting

Disc formatting is a procedure of an initial physical or logical benchmarking for a disc

In other word it’s an operation of magnetic medium benchmarking before data are recorded there

Large disks can be partitioned, divided into logical sections that are formatted with their own file systems

Formatting a disk involves two quite different processes known as low-level and high-level formatting

Low-level formatting is the formatting of disk surfaces and installing characteristics like sector numbers that are visible to, and used by, the disk controller hardware

High-level formatting is the process of setting up an empty file system on the disk, and installing a boot sector

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