Computer Systems Flashcards
Define “hardware”.
hardware refers to the physical components of a computer system. These are the tangible parts that work together to perform various tasks, such as processing data, storing information, and interacting with users.
Define “software”.
software refers to the programs and applications that run on a computer, enabling it to perform specific tasks. Unlike hardware, software is intangible and consists of instructions that tell the computer what to do.
Describe the relationship between hardware and software.
They work together to perform tasks and execute operations.
Explain “system software”. Give examples.
system software manages the computer system resources and acts as a platform to run application software. macOS, Linux, Android, and Microsoft Windows)
Explain “application software”. Give examples.
application software is software that performs end-user tasks. word processors, web browsers and spreadsheet software.
name the 5 things the OS manages.
processor(s)
memory
input/output (I/O) devices
applications
security.
Explain the main differences between low-level and high-level languages.
Abstraction:
Low-level: Close to hardware, less abstract.
High-level: More abstract, easier for humans to read.
Ease of Use:
Low-level: Difficult to learn and write.
High-level: Easier to write and understand.
Control:
Low-level: More control over hardware and memory.
High-level: Less control, abstracted away from hardware.
Portability:
Low-level: Not portable, machine-specific.
High-level: Portable across different platforms.
Execution Speed:
Low-level: Faster execution.
High-level: Slower execution due to translation.
Examples:
Low-level: Assembly, machine code.
High-level: Python, Java, C++.
what are the differences between assembly language and machine code
Assembly Language: Human-readable
Machine Code: Binary code (0s and 1s), directly understood by the cpu.
Translation:
Assembly Language: Needs to be translated into machine code by an assembler.
Machine Code: Already in the form that the CPU can execute directly.
Use:
Assembly Language: Used for low-level programming and system tasks (e.g., operating systems).
Machine Code: The actual code that runs on the CPU after being compiled/assembled.
Portability:
Assembly Language: Specific to a computer’s architecture.
Machine Code: Also specific to a computer’s architecture and CPU type.
machine code and assembly language are ___ level languages
low
what code do all processors execute
machine
what is assembly language used for?
assembly language is often used to develop software for embedded systems and for controlling specific hardware components
what is the ratio of correspondence between assembly language and machine code
1:1
what do high level languages and assembly language need to be translated into?
machine code
what are the advantages of low level languages
faster execution
greater control
efficient
hardware specific
smaller code size
what are the disadvantages of low level languages
difficult to learn
Time-Consuming
Less Portable
Low-Level Management:
Lack of Built-in Features:
what are the advantages of high level languages
Easier to learn and use
More readable and understandable code
Portable across different platforms
Faster development time
Rich libraries and built-in functions
Less need for manual memory management
what are the disadvantages of high level languages
Slower execution compared to low-level languages
Less control over hardware and system resources
Requires translation (compiling or interpreting) into machine code
May use more memory and processing power
which 2 of assemblers, interpreters and compilers, directly translate their inputs into machine code?
assemblers, compilers
what are the advantages of a compiler
Fast execution after compilation
Program can be run multiple times without recompiling
Errors detected before execution
Produces optimized machine code for better performance
what are the disadvantages of a compiler
Compilation process can be time-consuming
Requires re-compilation to test changes
Platform-specific code (may need recompiling for different systems)
More difficult to debug due to lack of immediate feedback
what are the advantages of a assembler
Directly converts assembly language into machine code
Faster execution of programs
Provides low-level control over hardware
Generates efficient, compact code
Suitable for system-level programming
what are the disadvantages of a assembler
Difficult to learn and use
Requires detailed knowledge of the hardware
Not portable
Time-consuming
Limited debugging tools
what are the disadvantages of a interpreter
Slower execution speed compared to compiled code.
The program must be interpreted every time it runs.
Requires the presence of an interpreter to execute the code.
what are the advantages of a interpreter
Executes code line-by-line, allowing for immediate feedback.
Easier to debug since errors are reported immediately.
Platform-independent, as the interpreter runs on different systems.
what is a bus?
A bus is a collection of wires through which data/signals are transmitted from one component to another.
explain the role and operation of main memory within the von Neumann architecture
In the von Neumann architecture, main memory stores both the program instructions and the data that the CPU needs to execute.
what is a clock within the von Neumann architecture
the clock is a crucial component that controls the timing and synchronization of all operations within the computer system.
what is an ALU within the von Neumann architecture
The ALU handles calculations like addition, subtraction, multiplication, and division, as well as logical operations such as AND, OR, NOT, and comparisons (e.g., equal to, greater than).
what is the control unit within the von Neumann architecture
the Control Unit (CU) is a key component of the CPU that manages and coordinates the execution of instructions.
what is a register within the von Neumann architecture
In the von Neumann architecture, a register is a small, fast storage location within the CPU used to hold data temporarily during processing. Registers are used to store intermediate results, instructions, and addresses that the CPU needs quickly during program execution.
explain the role of fetch in the Fetch execute cycle
the next instruction is fetched to the CPU from main memory
explain the role of decode in the fetch execute cycle
the instruction is decoded to work out what it is
explain the role of execute in the fetch execute cycle
the instruction is executed (carried out). This may include reading/writing from/to main memory.
why is secondary storage required?
permanent
large capacity
what are the differences between main memory and secondary storage
Main memory will be considered to be any form of memory that is directly accessible by the CPU (except for cache and registers).
Secondary storage is considered to be any non-volatile storage mechanism not directly accessible by the CPU.
what are the differences between ram and rom
RAM (Random Access Memory):
Volatile (loses data when powered off).
Used for temporary storage of data and instructions currently in use.
Read/write memory (data can be both read and written).
Larger capacity compared to ROM.
ROM (Read-Only Memory):
Non-volatile (retains data when powered off).
Used for permanent storage of firmware or essential startup instructions (e.g., BIOS).
Read-only memory (data cannot be modified easily).
Smaller capacity compared to RAM.
what is cloud storage?
Cloud storage refers to storing data on remote servers that can be accessed over the internet, rather than on local hard drives or physical devices.
what are the advantages of cloud storage
Accessible from any device with internet connection.
Easy to share files and collaborate.
Scalable storage, allowing for more space as needed.
Data is backed up automatically, reducing the risk of data loss.
Reduces the need for physical storage hardware.
what are the disadvantages of cloud storage
Requires an internet connection to access data.
Security risks, including potential data breaches.
Ongoing subscription costs.
Limited control over data management and privacy.
Dependent on the cloud service provider’s reliability.
what is an embedded system
is a specialized computer designed to perform a specific task or function within a larger system.
give examples of an embedded system
smart thermostats, fitness trackers, home security cameras, and automobile control systems.
give examples of a non embedded system
Desktop computer
Laptop
Smartphone
Tablet
Server
Gaming console
Personal computer
how does a optical disk work?
An optical disk uses a laser to read and write data. The surface of the disk is encoded with pits and lands, which represent binary data.
how does a magnetic disk work?
A magnetic disk works by using a read/write head that moves over a spinning disk coated with magnetic material.
how does a solid state drive work?
An SSD stores data using flash memory chips, which retain data even when power is off. It has no moving parts, unlike traditional hard drives, and data is accessed electronically through electrical signals.
what are the advantages of optical disks?
Portable and lightweight
Relatively low cost per GB
Durable and resistant to physical damage
Can store large amounts of data (e.g., CDs, DVDs)
Long shelf life for storage
what are the disadvantages of optical disks?
Slower data transfer speeds compared to other storage types
Susceptible to scratches and physical damage
Limited storage capacity compared to newer technologies
Requires a specific drive to read or write data
what are the advantages of magnetic disks?
High storage capacity.
Relatively low cost per gigabyte.
Reliable for long-term storage.
Can be easily rewritten and updated.
what are the disadvantages of magnetic disks?
Slower than solid-state drives (SSDs).
Can be damaged by physical impact.
Moving parts make them less durable.
Noisy during operation.
what are the disadvantages of solid state drives?
More expensive than traditional hard drives
Lower storage capacity (generally) compared to HDDs
Limited write cycles (can wear out over time)
Data recovery can be more difficult if damaged
what are the advantages of solid state drives?
Faster data access and boot times
More durable (no moving parts)
Lower power consumption
Quieter operation
More compact and lightweight
give 3 types of secondary storage devices
solid state, magnetic, optical
