(Done) 1. components of a computer system Flashcards
1
Q
Define Embedded system
A
- Computers built into other devices
2
Q
What are embedded systems often used for
A
- Control systems, They monitor and control machinery in order to receive a desired result
3
Q
List the components of a typical desktop pc (9)
A
- Power supply
- Case Cooling Fan
- CPU Heat Sink and Cooling Fan
- CPU
- Optical Drive
- RAM
- Mother Board
- Hard Disk Drive
- Graphics Card
4
Q
What is the CPU’s function
A
- Processes all the data and instructions that make the PC work
5
Q
What can affect the CPU speed
A
- Clock speed
- Number of cores
- Cache size
6
Q
Three main parts of the CPU
A
- Control Unit
- Arithmetic Logic Unit
- Cache
7
Q
What does the Control Unit do
A
- Manages the fetch - decode - execute cycle
- Controls the flow of data into and out of the CPU
8
Q
What does the Arithmetic Logic Unit do
A
- Does all the calculations
- Completes addition, subtraction, multiplication, division and compares the sizes of numbers
- Performs AND, OR and NOT logic operations as well as binary shifts
- Contains the accumulator
9
Q
What is Cache
A
- Slower than registers, faster than RAM
- Stores regularly used data so the CPU can access it quickly, when data is requested, the cache is checked first
- Very low capacity
10
Q
What are the sub-sections within Von Neumann architecture
A
Control unit
- Program Counter
Arithmetic Logic Unit
- Accumulator
Registers
- Memory Address register
- Memory Data Register
11
Q
What happens in the Fetch stage of the Fetch-Decode-Execute cycle
A
- Copy the memory address from the program counter to the memory address register
- Copy the instruction stored on the MAR to the MDR
- Increment the program counter to point to the address of the next instructions, ready for the next cycle
12
Q
What happens in the Decode stage of the Fetch-Decode-Execute cycle
A
- The instruction in the MDR is decoded by the CU
- The CU may then prepare for the next step by loading values into the MAR or MDR
13
Q
What happens in the Execute stage of the Fetch-Decode-Execute cycle
A
- The instruction is performed, this can be loading data from memory, write data to the memory, do a calculation or logic operation, change the address in the pc or halt the program
14
Q
Features of RAM and what does it do
A
- Can be read and written to
- Volatile
- On startup, the OS is transferred from the Secondary storage to RAM
- Programs are copied to the RAM whilst in use and are removed once closed
- Slower than CPU cache and faster than Secondary storage
15
Q
Features of virtual memory and what does it do
A
- When RAM is full, recently unused data gets moved to secondary storage
- If the data need to be used again, it is copied back to the RAM which can be slow due to lower read and write speeds on secondary storage
16
Q
Features of ROM and what does it do
A
- Non-Volatile
- Read Only
- Comes on a small factory-made chip built into the motherboard
- Contains the Basic Input Output system (BIOS)
- On start up, the CPU gets instructions on self-check ups from the ROM
17
Q
Define CPU clock speed
A
- The number of instructions a CPU can carry out per second (Hz)
18
Q
Define CPU cores
A
- A core is a part of the CPU that can process information independently
19
Q
Effect of CPU cache size on speed
A
- A larger cache gives the CPU faster access to more data it needs to process
20
Q
Features of the GPU and what does it do
A
- Specialised circuits designed for graphics and image processing
- Computers have BASIC GPU’s built into their motherboards or CPU’s
- Higher-end graphics cards are usually required for graphics intensive activities such as Gaming and software design
21
Q
Define primary storage
A
- Memory areas the CPU can access quickly
- E.g. CPU registers, cache, ROM and RAM
22
Q
Define secondary storage
A
- Where all data is stored when not in use
- E.g. magnetic HDDs, SSDs, CDs and SDs
23
Q
Features of primary storage (2)
A
- Fast read/write speeds
- Usually volatile
24
Q
Features of secondary storage (2)
A
- Non-volatile
- Slow read/write speeds
25
Features of a HDD (3)
- Data is stored magnetically in small areas on the disks tracks
- Long lasting and reliable
- Slow read/write
26
Features of an SSD (3)
- No moving parts
- Flash memory
- Significantly faster read/write than HDD
27
Types of flash storage (3)
- USB pen drives
- Memory cards
- Solid state drives
28
List optical disks (3)
- CDs
- DVDs
- Blu-ray
29
Types all optical disks can come in (3)
- ROM - read-only
- R - writeable-once
- RW - rewriteable
30
Why has optical disk usage decreased (3)
- Increased internet speeds make streaming and downloading viable
- Modern devices don't have optical drives
- Low capacity (typically 700MB) and slow read/write speeds
31
Advantages of optical disks (3)
- Cheaper per GB
- Portable
- Won't easily be damaged by water or shocks
32
Advantages of magnetic tapes (2)
- Greater storage capacity than HDDs
- Extremely low cost per GB
33
When are magnetic tapes traditionally used
- By large companies to store huge amounts of data in archive libraries
34
Functions of the OS (6)
- Communicate with the internal and external hardware via device drivers
- Provides a user interface
- Provides a platform for applications to run
- Allows the computer to multitask by controlling the memory resources and the CPU
- Deal with file and disk management
- Manage the security system
35
Function of Device drivers
- Used by the OS to communicate with the internal hardware or peripherals connected to the computer system
- Acts as a translator for the signals between the OS and hardware
36
What does a user interface do
- Allows the user to interact with a computer system
37
Types of user interface
- Graphic user interface (GUI)
- Command line interface
38
What is WIMP
- Windows, Icons, menus and pointers
- A way of structuring GUIs
39
Features of a command line interface (3)
- Text based
- Less resource heavy
- Can automate processes using scripts
40
What is the name for OSs that can run multiple applications simultaneously
- Multi-tasking OSs
41
How does the OS allow CPUs to multi-task
- By efficiently managing memory and CPU processing time
42
What responsibilities does the OS have in terms of file and disk management
- The organisation of data into a usable hierarchical structure
- naming, saving, movement, editing and deletion of data
43
Types of operating systems in terms of users
- Single-user
- Multi user
44
What does defragmentation software do
- Reorganises data on the hard drive to put fragmented files back together.
- it also moves files to collect all the free space together, this prevents further fragmentation
45
What does compression software do
- Reduces the size of files by permanently or temporarily removing data from them
46
What does encryption software do
- Scrambles data to stop third-parties from accessing it
