Computer systems

This set of flashcards contains essential concepts and definitions from the Computer Science curriculum, focusing on data compression, logic gates, programming languages, and computer architecture, to aid in exam preparation.

What is Huffman coding used for?

To compress data by calculating the number of bits required to store compressed information.

How do you calculate the bits required for uncompressed data in ASCII?

By multiplying the number of characters by 8, as each ASCII character is 8 bits.

What is run-length encoding (RLE)?

A data compression method that replaces consecutive repeated values with a single value and count.

What does the RLE representation of 0000011100000011 look like?

5 0 3 1 6 0 2 1.

Define 'hardware'.

The physical components of a computer system.

Define 'software'.

The programs and applications that run on a computer.

What is the relationship between hardware and software?

Hardware is the physical machinery, while software is needed to perform tasks on that machinery.

What is a truth table?

A table that shows the output of a logic circuit for every possible input combination.

What does NOT gate do?

It inverts the input; if the input is true, the output is false and vice versa.

What does AND gate do?

It outputs true only if both inputs are true.

What does OR gate do?

It outputs true if at least one input is true.

What does XOR gate do?

It outputs true if the inputs are different (one true, one false).

How many inputs can truth tables be constructed for?

Up to three inputs.

What logic gates are included in simple logic circuits?

NOT, AND, OR, and XOR gates.

What does a Boolean expression represent?

A mathematical expression that represents logical operations using variables.

What symbol represents the AND operation in Boolean expressions?

A dot (·).

What symbol represents the OR operation in Boolean expressions?

A plus (+).

What symbol represents the XOR operation in Boolean expressions?

A circle with a plus (⊕).

Which symbol represents the NOT operation?

An overbar (e.g., A̅).

What is system software?

Software that manages the computer's resources and runs application software.

What is application software?

Software that performs specific end-user tasks.

Identify the functions of an operating system (OS).

Management of processor, memory, input/output devices, applications, and security.

What are low-level languages?

Programming languages that are close to machine code and hardware-specific.

What are high-level languages?

Programming languages that are more abstract and easier for humans to read and write.

What is machine code?

A low-level language that is directly understood by the CPU.

What is assembly language?

A low-level programming language that corresponds directly to machine code instructions.

What is the role of an assembler?

To convert assembly language into machine code.

What does a compiler do?

Translates high-level source code into machine code.

What is an interpreter?

A program that executes instructions written in a programming language without converting them to machine code first.

How does the Fetch-Execute cycle work?

The CPU fetches the next instruction, decodes it, then executes it.

What are the components of the CPU in the Von Neumann architecture?

Arithmetic Logic Unit (ALU), Control Unit (CU), clock, registers, and bus.

What is RAM?

Random Access Memory, a type of volatile memory used for temporary data storage.

What is ROM?

Read-Only Memory, a type of non-volatile memory that stores firmware.

What is cache memory?

A small-sized type of volatile computer memory that provides high-speed data access to the CPU.

What is a register in a computer system?

A small amount of storage available directly in the CPU for immediate data manipulation.

What is the main difference between main memory and secondary storage?

Main memory is directly accessible by the CPU and is volatile, while secondary storage is non-volatile and not directly accessible.

What is volatile memory?

Memory that requires power to maintain the stored information.

What is non-volatile memory?

Memory that retains stored information even when not powered.

What types of secondary storage exist?

Solid-state, optical, and magnetic storage.

What is cloud storage?

Storage that takes place over the Internet at a remote location, typically using magnetic or solid state storage.

What are some advantages of cloud storage?

Accessibility, scalability, and remote data backup.

What are some disadvantages of cloud storage?

Dependency on internet connection, potential security risks, and data privacy concerns.

What is an embedded system?

A computer system with a dedicated function within a larger mechanical or electrical system.

Give an example of an embedded system.

Washing machine control system, microwave oven controller, or automotive control system.

What is the primary function of utility programs?

To perform maintenance tasks and manage files on a computer.

What are examples of system software?

Operating systems, device drivers, and utility programs.