Computer Science Module 1

CAPE Computer Science Unit 1

What is a computer?

A computer is an electronic device that accepts input, processes data, and produces output. It can perform a variety of tasks based on programmed instructions.

A computer is made up of ______ & ______ components.

Hardware and software

Computer Hardware consists of?

Input/Output Devices and Stoage Devices

List 3 input devices.

Mouse, Keyboard, Microphone, Joystick

Speakers, Monitors, and Printers are all?

Output devices

What is a specialized device?

A specialized device is a computer system designed to carry out niche tasks or solve specific problems

Give 3 examples of sepcialised devices

Braille Keyboard (for the visually impaired, Eye tracking hardware (for paralyzed individuals), Graphics Tablets (typically used by digital artists), Concept Keyboard (programmable buttons w custom overlay used in special needs education/at fast food restaurants)

What is memory?

Memory is any physical device that stores data, information, or programs either temporarily or permanently for a computer system to function.

What are the two types of main memory in a computer system?

Primary & Secondary

List the 4 types of Primary memory.

RAM, ROM, Cache & Registers

What is RAM?

Random Access Memory (RAM) is the space used to store information currently being used by the processor in a computer system.

What are the two types of RAM?

Static RAM and Dynamic RAM

Differentiate between Static & Dynamic Ram

Static RAM (SRAM) stores data in transistors and requires a consistent power flow. It does not need to be refreshed to remember the data being stored. It is used in cache memory. Dynamic RAM (DRAM), however, stores data in capacitors that gradually discharge energy. A periodic refresh of power is required in order to function. It is used to implement main memory.

Give 2 advantages of SRAM

• lower power consumption

• faster access speeds

Give 2 advantages of DRAM

• low costs of manufacturing

• higher memory capacities

What are ‘registers’?

Registers are tiny, fast storage locations built directly in the CPU that hold the specific data, instructions, or memory addresses the processor is actively working on. Registers are the fastest type of computer memory. (slower than RAM)

What is ‘cache memory’?

Cache memory is a high-speed memory in a computer that plays an intermediary role between RAM and the processor(CPU). Instead of making the CPU access RAM every time it needs data, cache stores copies of the most frequently used information right next to the processor to increase efficiency.

What is the purpose of Read Only Memory (ROM)?

Read Only Memory is a non-volatile memory type used by the computer to store parts of the OS needed to boot the computer.

Give the 3 types of ROM

Programmable Read Only Memory, Erasable Programmable Read Only Memory, Electrically Erasable Read Only Memory

What is PROM?

This is a type of memory that can only be programmed once, and cannot be reprogrammed afterwards.

EPROM is?

A type of ROM that can be reprogrammed via exposure to ultraviolet radiation. However, all previous data stored on the chip must be deleted.

What is the main difference between EPROM and EEPROM

Though both allow for data to be erased, EPROM uses ultraviolet radiation to do so and all previously stored data must be wiped. EEPROM however allows for parts of data stored on the chip to be erased and this is done electronically.

List 3 memory features

Speed size, memory size & words size

What is word size?

The number of bits a CPU can process, transfer, or hold in its internal registers in a single operation. Modern systems typically used 64-bit word sizes.

Memory size is?

The total capacity of a computer’s physical memory (RAM) usually measured in Gigabytes or Terabytes, which indicates how many programs and files can be kept active at once.

The Speed size is?

The frequency at which a processor executes instructions, measured in hertz (Hz) or Gigahertz GHz)

List 3 characteristics used to classify storage devices

Access speed, portability, cost, capacity, access method, volatility

Give 4 examples of storage devices

Hard Disk Drives, Solid State Drives, USB Flash Drive, (Memory Card) MicroSD, CD/DVDS

What are storage access methods?

Storage access methods define how a computer system reads data from and writes data to a storage device.

What is the difference between sequential access and direct(random) access?

Sequential access means the system must read or write data in a fixed, linear sequence from start to finish. to reach a specific piece of data, it must pass through all preceding data. On the other hand, Direct (Random) access allows the system to jump directly to any specific data block or memory address instantly, regardless of location.

What is access speed?

The time taken for data held in storage to be located and sent to RAM for execution

What is Parallel (Simultaneous) Access?

This means the system is able to read and write data at the same time across several channels or lines rather than one after the other. RAM is considered a parallel access device.

In terms of cost, primary storage tends to be _________ than secondary storage.

more expensive

Secondary storage comes with a ____ storage capacity then primary storage and come at a ____ cost per megabyte than primary storage

greater, lower

What is ‘portability’?

The ease of which the device and the data it stores can be attached to another computer system.

List the 5 main types of computers

Supercomputers
Mainframes
Minicomputers
Workstations
Microcomputers

Give one example of the use of a supercomputer

Nuclear research, weather forecasting, animationT

The performance of a supercomputer is measured in?

Floating-point operations per second (FLOPS)

The speed of a _____ is measured in millions of instructions per second (MIPS)

Mainframe

What is a workstation?

A workstation (a.k.a. desktop system) is a powerful computer designed for a single user to complete specialised tasks.

Give 2 examples of microcomputers

Laptops, Tablets, Mobile phone, Video Game Console