Computer Systems: Hardware and Software

Types and Components of Computer Systems

Hardware

• Encompasses the physical, electronic components forming a computer system
• Includes devices for both input and output

Internal Hardware Devices

• Central Processing Unit (CPU): Executes instructions.
• Processor: Performs calculations and operations.
• Motherboard: Connects and manages various components.
• RAM & ROM: Internal memory, RAM is volatile and ROM non-volatile
• Graphics & Sound Cards: Handles visual and audio output.
• HDD & SSD: Internal storage devices for data.
• NIC: Enables network connectivity.

External Hardware Devices

• Include components like Monitor, Keyboard, Mouse, Printer, and External Storage Devices.

Software

• Encompasses methods, commands, and instructions for device operation
• Programs that oversee the computer system and process data

Types of Software

Application Software

• Provides services enabling users to perform specific tasks
• Can be general-purpose or custom-made (specialist) software.
• Examples include spreadsheets, databases, and word processors.

System Software

• Designed to offer a platform where other software can operate
• Compilers: Translates high-level language to machine code
• Linkers: Establishes links among language processors for operational solutions
• Device drivers: Enables a device to function with an external connection

Analogue and Digital Data

• Computers read data in binary (0,1), known as digital data.
• Real-world data exists in analogue form, which goes beyond two values.
• Analogue data forms smooth curves, while data in digital form shifts in discrete steps.
• Computers convert real-world analogue data into digital form
• This is done using ADCs
• After processing it is converted back using DACs.

Main Components of Computer Systems

Central Processing Unit (CPU)

• The function is to understand and execute hardware and software operations within a computer
• Contemporary CPUs are commonly known as microprocessors

CPU Components

• Control Unit (CU) manages input/output devices
• Arithmetic and Logic Unit (ALU) executes computations and makes logical judgements
• Registers are small memory regions in the CPU

Internal Memory

Random Access Memory (RAM)

• It is temporary memory storage and is lost when power is off
• It serves in read and write functions and stores data that is currently running
• Operational speed can be improved by increased size

Read-Only Memory (ROM)

• It is permanent storage which is non-volatile
• Used for storing computers configuration such as BIOS

Internal Memory Differentiation

• RAM is temporary, ROM permanent
• RAM is volatile, ROM is non-volatile
• RAM is written to and from, ROM read only
• RAM used for storing data, files and programs of the OS currently in use
• ROM used for storing start-up data

Input/Output Devices

• Input devices: hardware allowing users for data input
• Output devices: presents computer output for humans. (e.g printer or monitor)

Input vs Output Devices

Input Devices

• Any hardware for data entry
• Can only send data
• Used for processing
• Complex

Output Devices

• Shows result
• Receives data
• Needed in order to display the outcome
• Simpler

Backing and Secondary Storage

• Requires storing significant amounts of data permanently
• The most common forms include Hard Disk Drives (HDD) and Solid State Drives (SSD).

Internal and Backing Storage

1. RAM erased when power is lost, ROM is read-only
2. Size: RAM and ROM are less than backing storage
3. Speed: RAM and ROM access faster
4. Price: Internal memory expensive
5. Portability: internal memories are fixed and backing storage portable
6. Access: internal memories CPU, backing storage first moved into RAM for CPU

Operating Systems

• Controls the operation of input, output, and backing storage
• Supervises the loading, running, and saving of application programs
• Deals with application program erros
• Maintains security
• Maintains the computer log

Operating Systems User Interfaces

Command Line Interface

• User types commands to communicate
• High Direct communication
• Not restricted to pre-defined options
• It's possible to change computer con guration settings
• Command must have correct form
• N.B - mainly for programmers to directly communicate

Graphical User Interface

• Uses WIMP (windows, icons, menu, pointing device)
• No need for commands
• icons represent applications
• More memory
• More complex operating system

Dialogue user interface

• Uses human voice to give commands
• Especially for assistance for the disabled

Gesture-based user interface

• Relies on motions in the hands
• Replaces mechanical input devices
• Human operation interface
• Possible unintentional movement will be picked up

Types of computers

• Desktop Computers*
• Usually refers to a general-purpose computer that is made up of a separate monitor, keyboard, mouse
• Which makes it not very portable

Advantages

• They are easier and less costly to upgrade and expand
• Spare parts are standardized, which makes them cheaper
• They tend to have better specifications for a given price
• No critical power consumption because they plug into a wall socket
• Due to fixed positions, they are less likely to be damaged or stolen
• As they usually have wired connections, they have more stable internet access

Disadvantages

• They are not particularly portable because they are made up of separate components
• More complicated because all the components need to be hooked up by wiring, which also clutters up the desk space
• Portable copies must be transferred using device or flashdrive for portability
• Mobile Computers*
• Refers to a type of computer where the monitor, keyboard, pointing device and processor are all together in one unit. This makes them extremely portable.
• Advantages*
• Lightweight
• Low power consumption
• Low heat output.

Laptop

• Refers to a type of computer; monitor, keyboard, pointing device and processor are 1 unit
• Lightweight / portable
• Low power consumption: lengthy battery
• Low heat output: cooling

Advantages

• Portability
• No trailing wires / desk clutter
• Easily used in public

Disadvantages

• Easily stolen
• Limited battery life
• May be awkward to use - keyboards / pointing devides
• Adding more RAM isn't easy

Smartphones

• Allow phone calls/running of apps using OS: such as iOS, Android, or Windows
• Mobile phones use Wi-Fi hot spots or using 3G/4G/5G mobile phone networks.
• Allow phone calls to be made
• Also run a number of computer applications
• Communicate with the internet

Advantages

• small / portable
• on the move connectivity
• can be used anywhere using WiFi and mobile phone networks

Disadvantages

• small screens and keyboards
• Web browsing
• photo drains

Tablets

• They work similarly to a smartphone, main differences include size
• Allow sending/receiving emails, a camera or MP3/4 player and able to use many apps.

Advantages

• Fast to boot up.
• Lightweight and touch friendly
• No heat

Disadvantages

• Tend to be expensive
• Have big touch screen, can be slow and error-prone
• tend to support more file formats than tablets.

Phablets

• A hybrid of a tablet and smartphone, it has much larger screens than a smartphone but are smaller than a tablet.

Uses

• Entertainment (streaming of music and videos, and television programs)

• Gaming (including group games)

• As a camera or video camera

• Internet use (online sales, social networks, using QR codes, and so on)

• Sending or receiving emails

• Global positioning system (use of maps to navigate to a location)

• Calendar functions

• Telephone banking (sending and receiving money using banking apps)

• Voice over Internet Protocol: telephone network using the internet, which also allows video calling

• Instant access to social networks (social contact with friends no matter where you are in the world)

• Instant messaging

• Office and business management (allows rapid voice and video communication)

• Education use (using interactive software to teach or learn from)

• Remotely control devices

• Laptops offer more expandability, smartphones are most portable

• Tablets and phablets fall somewhere in between

Examples

• Use of language, recognizing someone's face and to operate machinery

AI Impact

• Humans tend to think of think of robots, everyday uses include Driverless vehicles and Robotic research to help amputees

Robots

• Used to help carry out dangerous / unpleasant tasks and bomb disposal

AI Negative Impact

• Unemployment and dependency on technology

Extended reality

• refers to real and virtual combined environments.

Common examples

• AR virtual objects laid out in Pokemon GO, Safety and rescue operations' training,
• VR enables creation of new world with VR headsets and media

Input/output Devices

What they are

• Hardware device - Allows user to enter data / instruction to the computer directly
• Sends data to another device, it can't receive data from another device
• Receives user command and data to process under users control or direct data entry

Details

Input devices can be complicated to use, keyboard commands and numeric keypads or even a mouse is important

Keyboards

• Used for input, commands and the software
• Advantages include fast into a document and verification checks
• Disadvantages include being difficult to use

numeric keypads

• Allows customers to enter their PIN
• point of sale fails

Advantages

• Small in size and able to spread data

Disadvantages

• Smaller keys cause more difficulty

Mouse

Used for

• Opening and closing software
• grouping and deleting files

Image editing

• controlling the positions of a drawing

Advantages

• It's a faster method of keyboarding, Navigating
• Doesn't need a lot of dex space

Disadvantages

• Easy to damage, is a problem with wrist movement / data

TouchPad

• Integrate the lab top to the computer
• Aids ability in the big advantage

Disadvantages

• It makes it harder to control the pointer

Trickerball

• Great alternative using a mouse
• Using luxury card select function such a radio
• Doesn't need the same final control. Is easier to operators who their wris
• The needs Dex space, needs desk space etc

Remote control

• Using television can be controlled to remotely control processes

Joy sticks

• Helps control the simulator to mimic the actual controls

Driving wheel

• Similar advantages that are for the Joy sticks

Touch screens

• They are used for ATM'S and to make choices on screen

Scanners ,

• they document scanners to protect them against loss for damage

Digital cameas

• Allows the user to use them

Use

• Use them for audio conferencing or VP

Advantages

• It allows you to read to type into it

Sensor is more accurate

• Has more protection
• Automatic
• Are automatic systems etc
• They do for the sensors

Light pens

• Use to select object and display something that's needed

Devices

Magnetic Stripe Readers

• Security access for buildings or codes

Ship and pin readers,

• They are secure for all the payments

• Easy for inputting survey results

• And in all the devices

• Used to record students performance

• Allows the system to monitor a particular system

Output devices

2.3 - Output devices and their uses.

• Cathode ray tube, monitors CRT and large screens
• Light pens allow Designs to be created easier
• Use like Pens etc easy easy to use

Advantages and disadvantages,

• Can be seen at a wider range of the angles
• Use a variety of light pins
• Very very have and bulky , and cause fires
• Much more power needs etc , flicker in lead

Liquid Crystal Display screens

The end.